2320 & 2420 Flashcards
Where is most of the responsibility for TDG placed?
Employers and workers that :
- prepare dangerous goods for transport
- operate transport vehicles containing dangerous goods
- receive dangerous goods
- respond to emergencies involving dangerous goods
Who “owns” TDG law and enforcement?
Transport Canada, just like Health Canada “owns” WHMIS.
What are the classes of dangerous goods?
9 classes:
Class 1
Explosives, including explosives within the meaning of the Explosives Act
Class 2
Gases; compressed, deeply refrigerated, liquefied or dissolved under pressure
Class 3
Flammable and combustible liquids
Class 4
Flammable solids; substances liable to spontaneous combustion; substances that on contact with water emit flammable gases
Class 5
Oxidizing substances; organic peroxides
Class 6
Poisonous (toxic) and infectious substances
Class 7
Radioactive materials and radioactive prescribed substances within the meaning of the Atomic Energy Control Act
Class 8
Corrosives
Class 9
Miscellaneous products, substances or organisms considered by the Governor-in-Council to be dangerous to life, health, property or the environment when handled, offered for transport or transported and prescribed to be included in this class
What is a dangerous good according to the TDG Act?
Any product, substance or organism included by it’s nature or the regulation in any of the 9 classes in the TDG Act schedule.
Discuss safety marks and placards.
Safety marks must be on smaller dangerous goods containers under 450L.
Placards must be on bulk containers of dangerous goods over 450L.
Transport units (highway tanker) transporting dangerous goods must be placarded. - this alerts first responders. (not required on ships/aircraft)
Who requires TDG training?
Every person engaged in the handling, offering transport, or transporting dangerous goods.
Handling includes packing and receiving goods.
What must accompany dangerous goods when transported?
Very specific documents and signs/placards as appropriate.
What is required for TDG documents?
Documents must be transported with dangerous goods and include the following 4 pieces of information.
- UN ID number
- Official shipping name
- Hazard class
- Packing Group (if applicable)
Employers can design own documents, and can be hand written so long as required information is clear and indelible.
What information SHOULD be included on TDG documents?
9 items:
- Date
- Shipper name
- Shipper address
- 24 emergency number (which may be CANUTEC)
- Quantity & unit of measure
- Number of packages
- Shipping name (the TDG name of the dangerous good)
- TDG class
- UN number
Where should TDG documents be stored during transit?
Somewhere clear/obvious, and easily/safely accessible to the driver.
Must be accessible in the event of an accident.
Discuss TDG Placards
Required on containers with over 450L.
Required on transport vehicles, on both ends and both sides.
Must be in TDG class colour, in a diamond, with contrasting background.
Must usually be 250mm per side, unless on small container when can be reduced to min’ 100mm.
Must be weather-proof, visible, and durable.
Must be on vehicle before loading and removed when empty.
What are UN specification codes?
United Nations standard packaging codes.
Packaging with these codes is based on standards published by the UN.
The code includes a lot of information about the packaging.
What are the three major groups assigned roles by TDG law?
Handlers
Offerors for transport
Carriers
List the characteristics of a hazardous Material
Chemical or biological agents
Prevalent in the workplace
Has a history of causing occupational disease
Tend to be recognized by most workers/public
Have received significant media coverage
Perceived risk often higher than actual risk
Often governed by prescriptive regulation
Subject to regulatory oversight
Often produce anxiety in the workplace
Exposure control strategies generally well developed
Transportation highly regulated
List & describe the four functions of a manager.
POLC (aka PLOC)
Plan work
Organize work
Lead the team in the work
Control the work
Briefly describe the roles of federal and provincial/territorial governments in regulating hazardous materials.
The Canadian Constitution assigns responsibility for regulating certain things to provincial/Territorial governments and certain other things to the federal government.
Provincial
Safety of workers exposed to HM
Disposal of HM within the province
Federal
Safety of workers exposed to HM in federally regulated workplaces
HM disposal outside of Canada
Transport of HM by road/rail/ship/aircraft (note, road transport is delegated to provincial ministry)
Describe an exposure control plan as required by Canadian OHS law.
(a) a statement of purpose and responsibilities;
(b) risk identification, assessment and control;
(c) education and training;
(d) written work procedures, when required;
(e) hygiene facilities and decontamination procedures, when required;
(f) health monitoring, when required;
(g) documentation, when required.
Define hazardous material
HM is not defined in any Canadian OHS law. Other sort-of-related terms like hazardous product, controlled product and designated substance are defined in OHS law but not HM.
Canadian OHS laws are filled with regulations related to prevention of adverse worker exposure to materials that are hazardous to their health.
List the elements of a WHMIS program.
Worker Education & Training
Supplier Labels
SDS
Describe the information elements of WHMIS as a results of completing a standard WHMIS education course.
Basic understanding of the WHMIS program in the workplace
How to recognize and use WHMIS information
Major hazards of products in the workplace
Rights and responsibilities of employers and workers
Required contents of labels and SDS sheets including how to understand pictograms and terms.
Compare and contrast WHMIS education and WHMIS training.
WHMIS education teaches workers about the WHMIS system and hazards. The focus is on the WHMIS system.
WHMIS training trains workers how to safely work with the hazardous materials and what to do in the event of a problem. Training is specific to the materials and work being done.
Define acute
Sudden onset, brief duration, or short exposure.
Define carcinogen
A hazardous material that may cause cancer.
Define “chemical name”
A scientific designation of a substance made according to a set of rules and internationally recognized.
Define chronic
Gradual/prolonged onset, long-term duration, or repeated exposures.
Define corrosive material
A material that is liable to destroy or damage another material by chemical action.
Define IDLH
Immediately Dangerous to Life or Health
Used related for respirator selection.
The airborne concentration that poses a threat of death or permanent adverse health effects upon exposure.
Workers must have means of escape from environment in case of respirator failure.
When levels greater than IDLH, highly reliable breathing apparatus required.
Define skin irritatants
A material that may cause an allergic skin reaction after contact with skin.
Define skin irritatant
A hazardous product that may cause reversible damage to the skin such as redness, itching, or swelling.
What are the four WHMIS test questions?
What are the hazards of the product?
How are you protected from those hazards?
What do you do in case of an emergency?
Where can you get further hazard information?
What important information can be found on an SDS sheet?
Material hazards.
Recommended controls (engineering, administrative, PPE).
First aid and spill response recommendations.
Additional: disposal information, contact information, manufacturer information.
List differences between WHMIS 1988 and WHMIS 2015.
Different symbols/pictograms
MSDS are now SDS with new standard format
There is a new classification system for controlled/hazardous products.
There is a new grouping system for hazards.
Name the most common forms of asbestos and types of asbestos-containing materials found in Canadian workplaces.
Chrysotile (most common) Amosite Crocidolite Tremolite Actinolite Anthophyllite
Floor tiles, ceilings, brake pads, insulation, ship building.
List diseases associated with overexposure to asbestos fibres.
Pneumoconiosis and cancer (mesothelioma, lung cancer, GI cancer).
Describe the methods most commonly used to manage asbestos-containing material in place.
Inventory of ACM
Decision on fate of ACM (manage or remove/abate)
Managing in place
Removal/abatement
What is asbestos?
Asbestos is a commercial term that includes six regulated asbestiform silicate minerals (silicon + oxygen).
What percentage of asbestos in a material does WorkSafeBC require for it to be designated as asbestos-containing?
1% per course (0.5% per OHS reg).
Recognized occupational causes of pneumoconiosis
Silicosis
Asbestosis
Other
What is required to inventory ACM?
Determine: What kinds of ACM are present Where? Quantity? Condition of the ACM.
When should asbestos be abated (removed)?
When ACM risk is high and easily accessible to workers or the public. Examples commonly include fire insulation because it was extremely friable.
When ACM has a moderate or high risk and enclosure or encapsulation is not feasible.
When the perceived risk of ACM is unacceptable and abatement will address worker or public concerns.
What is white asbestos?
Serpentine minerals - Chrysotile are known as white asbestos.
It is the most commonly used asbestos (~90% of world use).
Wavey/curly fibers.
What is amphibole asbestos?
The other 5 asbestos fibers
Amosite, crocidolite, tremolite, actinolite, anthophyllite.
Straight, rod-like fibers.
What are the three most common types of asbestos?
Chrysotile (white asbestos)
Amosite (brown/grey asbestos)
Crocidolite (blue asbestos)
How is testing performed to test for asbestos?
Bulk sampling.
- Safe collection technique/sealing
- Sent to lab (1-10g)
- polarized microscopy
How is asbestos classified in Canadian OHS law?
Form of ACM Type of asbestos fibers Percentage of asbestos in material Friability of ACM Amount and location of the ACM
This all determines whether it is low/medium/high risk.
List five sources of inorganic lead and work activities where exposure may occur.
Lead-acid batteries, automotive repair
Lead solder - Jewlers or electricians soldering
Lead containing ore - foundry/refinery workers
Firearm ammunition - Police, shooting ranges
Lead paint, panels, tiles, piping - Demolition/renovation/lead abatement workers
Explain how lead dust and fume enters a workers’ body.
Inhalation and ingestion.
Breathing dust or fumes
Lead contaminated food/drink
Nail biting with lead on hands and other habits of putting objects in mouth
Organic lead can be absorbed through the skin (some pesticides)
Describe the health effects of acute and chronic exposure to inorganic lead.
The health effects from lead are the same regardless of the source or route of exposure.
Early lead toxicity symptoms are non-specific and can be difficult to recognize.
Acute toxicity can cause lethargy, headache, hyporexia, metallic taste.
Chronic toxicity can cause abdominal pain, constipation, muscle/joint pain, memory problems.
Lead toxicity can cause neuropathy, GI Dz, renal Dz, reproductive Dz. Also carcinogenic.
List and describe the elements of a lead exposure assessment.
1, Identification of sources of inorganic lead in the workplace.
2, Observation of work activities to determine which practices expose workers to lead inhalation or ingestion.
3, Hierarchy of controls. Where exposure cannot be eliminated, air monitoring and surface sampling necessary to determine exposure levels.
4, Health monitoring, often including blood sampling, should be implemented where practicable.
What is organic lead? what is inorganic lead?
inorganic or elemental lead is just lead. Organic lead is a combination of lead and carbon.
List 5 common products manufactured using lead.
Lead-acid batteries
Lead-paint on roads
Lead-containing weapons/ammunition
Decorative glass
Protective coating on underwater cables
Differentiate fumes vs vapours.
Vapours are gaseous. Solids heated turn to liquid and then gas. A gas rising from a heated liquid is a vapour.
Fumes are small solid particles suspected in the air. Smoke is a fume.
When lead is heated, it melts, some lead may be vapourized and turn into a gas. In the air, the lead vapour cools and forms particles in the air - now a fume.
Removal of which two hazardous materials does WorkSafeBC require 48 hours notice in advance?
Asbestos and lead.
List two physical forms of lead that can enter a worker’s body.
Fine dust and fumes.
List 5 similarities between asbestos and lead OHS regulations
- Exposure control plan requirements
- Air monitoring requirements
- Highly prescriptive methods of removal
- Removal risk classification levels
- Notice of project requirements
List 5 legal methods for the removal of lead-based paint/coatings.
Chemical strippers Manual scraping Heat guns Water jet blasting Dry ice blasting Specific dry abrasive blasting Wet abrasive blasting
What is a toxic process gas?
A gas that meets criteria in Canadian federal HPR (Hazardous Product Regulation).
Category 1, 2, or 3 for acute toxicity and is used in one of the following:
1, Part of an industrial process
2, Refrigeration
3, Material treatments (such as disinfection systems)
Specifically:
Anhydrous ammonia, chlorine gas, and sulfur dioxide.
What is Process Safety Management?
Important:
“PSM is an analytical tool used to prevent the release of substances defined as highly hazardous chemicals”
It is the formal process of assessing and controlling OHS issues created by process lines.
(Developed by OSHA)
Typical examples would include large scale industrial processes where each individual component has a direct impact upon the other components. This can lead to hazards when there is a change to any 1 component of the overall process.
What elements make up a typical process safety management plan?
Name at least 6.
Process Safety Information Process Hazard Analysis Operating Procedures Training Contractors Mechanical Integrity Hot Work Management of Change Incident Investigation Compliance Audits Pre-startup safety review Emergency planning and response Trade secrets Employee participation
What are common uses of ammonia in the workplace?
Refrigeration
Fertilizer
Component in industrial production.
What are the effects of overexposure to ammonia?
Irritation of nose and throat.
Coughing, shortness of breath, tightness of chest.
Burns to the eyes, nose, throat (anywhere with moisture).
Pulmonary edema.
What is the federal HPR?
Hazardous Product Regulation
Federal legislation that is related to WHMIS and toxic process gas. This regulation is referenced for definitions in BC OHS Regulation.
What is a process flow diagram?
A display of the relationship between major equipment/processes.
A simple diagram that depicts processes and how they are related in a larger design. It does not provide details of how each process functions or specifically how different components are connected (rather it shows that they are and in what direction).
Commonly used in chemical and process engineering.
What is a piping and instrumentation diagram/drawing?
A P&ID is a diagram that shows specifically how different components in an industrial process are connected and controlled.
There are standards symbols for these schematics.
What is anhydrous ammonia?
NH3.
A gas at room temperature, often stored under pressure as a liquid.
Anhydrous = without water (no water added)
Aqueous ammonia is ammonia with water (such as household ammonia cleaner). Risks associated with aqueous ammonia are relatively low.
Discuss how ammonia refrigeration system safety is governed by OHS and related laws in BC.
Ammonia refrigeration systems are a concern because they contain large quantities of anhydrous ammonia, they are typically in large urban areas, and they are complex mechanical systems with potential for failure.
WorkSafeBC has a combination of performance-based and prescriptive regulations for all toxic process gases
Technical Safety BC has detailed prescriptive regulations for boilers, pressure vessels, and refrigeration systems. These include:
- Mandatory standards of equipment design
- Mandatory standards of equipment installation
- Qualified operators and maintenance staff
What workplaces and work processes commonly use chlorine?
Disinfectant (swimming pool, water treatment plant, sewage treatment, community water supplies)
Also used in some manufacturing:
Pulp/paper industry, pool chemical products, cleaning products, mining processes, bleach manufacturing, plastics manufacturing.
What are health effects of chlorine overexposure?
- Nose/throat irritation
- Pulmonary edema
- Coughing, shortness of breath, dyspnea
- Onset of chronic asthma
- Corrosive burns (skin/eyes)
- Cold injuries with liquid contact
How are bulk quantities of chlorine usually transported?
Large pressurized containers on rail cars or tank trailers.
Alt - large volume pressure cylinders.
What is required for day-to-day safe work procedures when working with chlorine?
OHS and public safety regulators have regulations that require/enforce:
Design standards for equipment Design standards for facilities Qualification for workers Safe work procedures for work and emergency response Exposure control plans
What is anhydrous chlorine?
Chlorine, Cl is a diatomic molecule. Meaning that there are two atoms in one molecule: Cl2.
It is a gas at room temperature, and often stored under pressure to store in liquid form (anhydrous chlorine).
Sodium hypochlorite is a solid powder that can be dissolved into water to make bleach. Some chlorine gas is released from sodium hypochlorite/bleach in quantities that are generally considered to be safe.
What is the Transport Canada Emergency Response Guide?
The ERG is a reference guide that categorizes hazardous materials and gives important information on each category.
The information provided for each category is reliable and useful for the development of safe work and emergency procedures.
What certification/training is legally required for persons working with chlorine in Canada?
There are several good certification/training programs in Canada.
These programs are not required by any prescriptive legislation.
Legislation does require that workers be “qualified” and so due diligence requires that these programs of an equivalent be used.
Describe the health effects of inhalation of hydrogen sulphide.
Odor.
Irritation - eyes, nose, mouth, throat, lung. Loss of appetite.
Loss of smell
Headache, dizziness, ataxia, collapse.
Respiratory paralysis, cardiac arrhythmia, death.
How H2S is formed?
1, organic material
2, anaerobic conditions
3, sulphate-reducing bacteria
= H2S
Explain the role of OHS regulators and energy boards in regulating worker exposure to hydrogen sulphide
H2S is covered by broad hazardous material OHS laws, and a few specific H2S regulations in known high-risk industrial activities (oil & gas).
National and provincial energy board regulators, in their activities to protect public safety, indirectly improve worker safety.
Note:
- BC Oil and Gas Commission
- Canada Energy Regulator
What is hydrogen sulphide?
H2S
Usually a gas (unless under high pressure or extreme cold)
Highly toxic
In tiny amounts, has a rotten egg/sulphur smell
H2S is typically a by-product of other processes
H2S is created by anaerobic decomposition of organic material
Rapidly dissolves in water (or mucus membranes) to produce sulphuric acid.
What is sour gas?
Natural gas mixed with H2S.
The natural gas industry processes sour gas to remove H2S.
What is the usual H2S ceiling?
The ceiling limit for hydrogen sulphide is 10 parts per million.
C 10 ppm
No worker, at any time, for any duration, may be exposed to more than 10 ppm.
What is the H2S IDLH?
The Immediately Dangerous to Life or Health limit for hydrogen sulphide is ~100 ppm
What are the health effects of hydrogen sulphide?
Inhalation:
Airway irritation, pulmonary edema, headache, respiratory paralysis, unconsciousness, death.
Long term effects may cause asthma, RADS (reactive airway dysfunction syndrome), nervous system dysfunction.
Skin contact:
Cold effects from liquid form.
Eye contact:
Irritant. Cold effects from liquid form.
Not known to be carcinogenic, teratogenic, embryotoxic, reproductive toxin, mutagenic.
What is the rule of thumb for H2S concentrations?
1-10-100-1000ppm
1= Smell 10= Irritation (Regulatory limit) 100= Severe nose/throat/lung irritation, loss of appetite (severe enough to prevent self-rescue) 1000= Respiratory paralysis, arrhythmia, death
(around 150ppm, sense of smell stops working)
What workplaces may have H2S? (Name 4/7)
Gas plants, refinaries, petro-chemical plants, sulphur recovery plants.
Underground mines
Tank cars (railway), tank trucks (road)
Commercial laboratories
Septic tanks, sewers, manure handling areas
Pulp & paper mills
Pipelines
What is the LEL? (context, fire risk)
LEL = Lower Explosive Limit
The lowest concentration (%) of a gas or vapour in air capable of producing a flash of fire in presence of an ignition source (arc, flame, heat).
Sometimes called the Lower Flammable Limit.
Percentage vs ppm
1% = 10,000 ppm
What is the UEL? (context fire risk)
UEL = Upper Explosive Limit
The concentration (%) above which a gas will not burn.
What is the flammable range? Specifically for H2S.
The flammable range, is the range between the LEL and the UEL.
H2S has a range of 4 - 44.
(4% to 44%)
What H2S-specific sections are in the BC OHS Regulation?
The only H2S-specific regulations are under part 23, Oil and Gas.
What H2S-specific sections are in the BC OHS Regulation?
The only H2S-specific regulations are under part 23, Oil and Gas.
Why do most OHS regulations in Canada not have specific H2S sections in industries where H2S is a known hazard?
While there are not specific H2S sections/requirements, the general requirements for chemical hazards and confined space hazards provide sufficient regulation that would include H2S hazards.
List 5 areas of regulation (OHS & public safety) that apply to H2S, anhydrous ammonia, and chlorine gas.
- Design standards for equipment used in processes.
- Design standards for process facilities.
- Mandatory or highly recommended qualifications for workers who operate processes.
- Requirement for safe work procedures for normal work and emergency response.
- Exposure control plans.
Why might management of a H2S OHS program be potentially more challenging than for ammonia or chlorine?
There are uncertainties about the presence and quantity of H2S in a given situation.
Emergency scenario’s involving release and exposure of H2S can be sudden and with severe consequences.
How should an OHS program for H2S be started/approached?
1, Read the regulations and the ‘nearly law’ best practices carefully/completely.
2, Read the guidance documents from OHS and energy board regulators carefully/completely.
What is the maximum recommended short term exposures to H2S in a given day per the ACGIH?
5.
The ACGIH recommends no more than 5 short term exposures to H2S in a day.
American Conference of Governmental Industrial Hygienists.
How many breaths of high H2S concentrations are necessary to kill a worker?
1.
Name three broad areas of regulation for H2S.
1, General OHS regulations for hazardous materials.
2, Specific OHS regulations for activities where H2S is a known hazard.
3, Public safety laws, such as those administered by energy boards.
Why would a worker remain in an area of high H2S concentrations when there is a distinct/nauseating odor?
At high levels, H2S dissolves into the blood and paralyses the olfactory part of the brain, eliminating the sense of smell. Workers may be unaware of the high levels.
What is upstream or downstream oil and gas production?
The oil and gas production supply chain is divided into three areas: upstream, midstream, downstream.
Upstream - identification, extraction, and production of raw materials
Downstream - Post production of crude oil and natural gas
Midstream - Connects up/down stream. Transportation & storage.
What is H2S Alive?
A 1 day course offered by ENFORM for people entering the oil/gas industry. Covers H2S safety.
It is nearly impossible to work in upstream oil and gas without this course.
List three energy regulators that indirectly improve the safety of oil & gas workers.
The Canada Energy Regulator
Alberta Energy Regulator
BC Oil and Gas Commission
All three enforce laws to protect the public, which also result in worker protection.
What is part 5 of the BC OHS regulation?
Chemical agents and biological agents.
What is part 6 of the BC OHS regulation?
Substance specific requirements.
What jurisdiction is responsible for the transport of hazardous materials across provincial borders?
Federal, transport Canada.
What justification is responsible for transportation of hazardous materials on roads within a province?
Provincial. CVSE in BC
Commercial vehicle safety and enforcement
What justification is responsible for the use of hazardous materials in an RCMP lab?
Federal, labor Canada.
What justification is responsible for hazardous materials at a local hospital?
Provincial, WorkSafeBC
What justification is responsible for disposal of hazardous material waste at local landfill?
Provincial, ministry responsible for environment.
What does WHMIS stand for?
Workplace hazardous material information systems
What is WHMIS - explain to a worker.
Required at every workplace in Canada
A system to provide information to workers about hazardous materials they work with/around
Requires that workers using hazardous materials (hazardous products in legislation, previously controlled products) be educated and trained
Requires workers to be educated on the WHMIS elements (labels, SDS)
Requires that workers are trained in the safe use of hazardous materials and appropriate PPE.
Requires that workers be trained to respond to accidents and spills involving hazardous materials.
Describe common uses of ozone in the workplace.
- Swimming pool water treatment
- Drinking water disinfection (bottled water)
- To prevent food from spoiling (example ozonated ice)
Other Uses:
- Waste water treatment
- Cooling tower water treatment
- Treatment of storage water, fishing industry
- Purifying feed water in fish farming
- Disinfection (abattoirs, aquariums, hospitals)
- Pulp bleaching
- Medical treatments
- Perfume manufacturing
- Odour and smoke control
- Air purifiers
List health effects associated with overexposure to ozone.
Acute
Minor irritation of eyes & URT (low due to low water solubility)
Irritation of LRT (often described as a dull chest pain)
Headache
Pulmonary edema with higher concentrations
Chronic (either chronic low exposure, or chronic symptoms after a high exposure)
Reduced lung function, possible premature aging of body.
No evidence of carcinogenicity, or fetal-toxicity.
Explain the concept of a lower respiratory tract irritant.
There are fewer nerves in the lower respiratory tract than in the upper. Irritation of the LRT often feels more like a dull ache/pain than the true irritation of the URT.
Ozone is more of a LRT irritant than URT. As such workers may be less aware of symptoms if they are exposed.
Discuss similarities between ozone and chlorine as hazardous materials.
Both gasses, and toxic process gasses.
Both cause severe respiratory damage and can be fatal.
Both oxidizing agents, and can be used for disinfection.
Both can be used for disinfection of things like drinking water, in which case large quantities used.
Both have similar regulations and require similar control systems.
Describe common technologies used to generate and destroy large quantities of ozone in the workplace.
The most common system to use ozone:
- Water content of air decreased in an air dryer.
- Dry air moved into ozone generator (most commonly corona discharge). O2 breaks down and some O3 formed
- Compressor moves O3 through an injector into contact tank
- O3 meets water in contact tank, disinfection process
- Excess O3 released from contact tank into ozone destructor, where it is catalysed into O2
- Water from contact tank passed through de-ozoning filters and ready for use.
What is ozone?
O3.
A gas under normal circumstances, heavier than air.
Extreme pressure/cold required to liquify (not normally done)
Toxic process gas.
It is part of the smell after lightening.
Electricity can separate O2 molecules, allowing them to reform as O3.
Stratospheric ozone is the earth’s ozone layer. (good)
Ground ozone is an industrial pollutant which can cause environmental damage. (bad)
Ozone used in the workplace is good and bad. It has practical (good) uses, and can be harmful in excess or when not controlled (bad).
Discuss differences between ozone and chlorine.
Chlorine is almost never made on-site. It must be transported and stored. Ozone can be made on-site and is not stored in large quantities.
Chlorine is more water soluble than ozone. This makes it more of an upper respiratory tract irritant than ozone.
List 7 properties of ozone.
Gas at normal temperature/pressure
Heavier than air
Pungent odour
Excellent disinfectant
Blue in pure form
Invisible when in air
Highly reactive
What pictograms apply to ozone?
Health hazard
Oxidizer
Environmental Harm
Exclamation Mark (irritant & toxic)
List 4 properties of ozone as a disinfectant.
Used before other disinfection methods in system.
Greater effectiveness than other methods.
No residue in water.
Ineffective against algae at standard concentrations.
List 4 properties of chlorine as a disinfectant.
Used as last disinfection method in system.
Used in many forms as a disinfectant.
Leaves residue in water.
Effective against algae.
Discuss ozone generated from UV radiation.
A small amount of ozone is produced, and is typically used to disinfect small quantities of water.
Discuss ozone produced from corona discharge.
A high voltage of electricity is passed through a point, resulting in the electrical potential breaking down the molecules surrounding the point. Bluish light produced (the corona), and ozone formed.
Dried air is typically used to reduce unwanted products of reaction.
Discuss ozone desctructors.
A device or oven that used a catalytic process to convert ozone gas into harmless oxygen.
This permits for safe venting into the environment.
Discuss de-ozoning filters
Filters that will remove excess ozone in the ambient air or prior to entering target water source.
What is an ozone contact tank?
A container where ozone is allowed to contact water.
What is the ACGIH?
The American Conference of Governmental Industrial Hygienists.
That is TWA?
Time-Weighted Average.
The term is used to describe the exposure limit (ppm) for workers assuming an 8-hour work day and 40-hour work week.
What is OEL?
Occupational Exposure Limit.
What is the typical OEL for ozone?
TWA for heavy work is 0.05 ppm.
TWA for moderate work is 0.08 ppm.
TWA for light work is 0.1 ppm.
There are usually no prescriptive ceiling limits or 15 min exposure limits for ozone.
What is the IDLH generally reported for ozone?
Typically 5 ppm.
Discuss routes of exposure with ozone.
`Ozone exposure is typically considered to be through inhalation.
Absorption is generally not an issue. Ozone is not very water soluble, and direct contact would require high levels of exposure over time to break down the surface layers of the skin enough to cause any significant harm.
Ingestion is not likely due to the nature of the gas and it’s insolubility.
Discuss symptoms of ozone exposure at different concentrations.
The effects are dependant upon breathing rate/volume. As such effects under heavy work conditions are worse than light work conditions.
0.01 ppm - Odour threshold
0.1 ppm - Minor eye, nose, throat irritation
0.2 ppm - headache, dry cough
0.6 ppm - chest pain (dull)
1 ppm - Lung irritation, coughing, severe fatigue
5-10 ppm - IDLH
What is the ATSDR?
The Agency for Toxic Substances and Disease Registry (American)
What is the LEL and UEL of ozone?
LEL = Lower Explosive Limit UEL = Upper Explosive Limit
Ozone has neither, it is not flammable. It is however oxidizing, and so there is a fire risk.
Discuss laws related to ozone safety.
Ozone is not likely to cause a public health hazard, so public health laws are not a concern as they are for chlorine or ammonia.
Ozone is covered under general hazardous material regulations, and toxic process gas regulations.
There are no ozone-specific laws in Canadian OHS legislation.
What elements are included in safety guidelines for workplace ozone safety?
- Design standards for equipment
- Design standards for facilities
- Training/qualifications for workers
- Written safe work procedures and emergency procedures
- Exposure control plans
- Use of supplier manuals for equipment
What is the CRBOH?
The Canadian Registration Board of Occupational Hygienists.
What key engineering controls would be expected in a facility where ozone is generated in large quantities to disinfect drinking water?
- Ozone monitors (working room and vent post ozone destroyer)
- Interlock system between monitors/generator/destruct unit
- Ventilation systems in generator and filler rooms
What is Silica?
SiO2
Silicon dioxide, a chemical compound.
One of the most commonly occurring minerals on earth.
Usually a major component of sand. Quartz is silica.
What is silicon?
Si
Silicon
A chemical element.
Hard, brittle, crystalline solid.
8th most common element in the universe, and is rarely found in pure form in the earths crust.
What is silicate?
Any anion of silicon and oxygen.
Often used to denote types of rock that a predominantly composed of silicon oxides.
Silicates constitute the majority of the earths crust. (eg, sand)
What are the differences between crystalline and amorphous silica?
Crystalline silica is always more toxic than amorphous silica.
What is crystalline silica?
Any compound of silicon dioxide that has a regular structure.
What is amorphous silica?
Any compound of silicon dioxide that has an irregular structure.
What workplaces and activities are at highest risk of crystalline silica dust overexposure?
Trade contractors (construction)
Building construction
Heavy and civil engineering construction
Metal ore mining
Cement and concrete product manufacturing
What are silicones?
Silicones are polymers including any inert compound of repeating siloxane units.
Siloxane units are chains of alternating Si and O atoms.
Si-O-Si-O-Si
Name a type of silicate mineral that is a famous hazardous material.
Asbestos.
What is siloxane?
A siloxane is a compound including alternating chains of silicon and oxygen atoms.
Eg, Si-O-Si-O-Si
Differentiate crystalline and amorphous solids.
Both are solids, and so there are atoms fixed in position with each other that vibrate.
Crystalline solids form repeating patterns, where the patterns of connected atoms all look the same (crystals, metals, salts).
Amorphous solids form irregular patterns, where the sections of atoms each look differently. (glass, wax)
Compare the risks of silica exposure in processing silica sand versus making glass.
Both of these processes involve working with silica.
Silica sand is a crystalline silica, whereas glass is an amorphous silica.
The crystalline silica is more toxic than the amorphous form, as such the risks for the silica sand processing are higher than the making of glass.
Discuss diatomaceous earth.
Diatomaceous earth is a siliceous sedimentary rock consisting of fossilized diatoms.
It is an amorphous silica in it’s natural state which is not very toxic.
It can be exposed to high heats to change it into a crystalline silica called “calcined diatomaceous earth”. This is more toxic and is often used as a ine filtration medium (example, in pool filters).
Discuss “total”, “inhalable”, and “respirable” as occupational hygiene terms.
These terms all refer to the size of molecule where they can enter into the respiratory tract and cause illness.
Total, means the maximum size where the particle will cause illness (typically 100 microns and smaller)
Inhalable means the particles are small enough that they will pass the upper respiratory tract and enter the middle respiratory tract.
Respirable means the particles are small enough to pass to the lower respiratory tract and alveoli. (typically under 5-10 microns)
What pictograms are applicable to silica?
Harmful to health.
No others.
What factors affect the health effects of silica exposure?
The form of the silica (amorphous vs crystalline)
The silica particle size (are the particles small enough to get into lungs)
The dose, concentration x time (how much exposure)
Individual susceptibility
What is silicosis?
A recognized occupational disease cause by exposure to silica dust.
What are the health effects of concern related to silica?
Crystalline silica dust particles small enough to be respirated can cause:
- silicosis
- lung cancer
- COPD & pulmonary emphysema
Three forms of silicosis:
1, Acute silicosis (v.high concentrations, symptoms within a few weeks up to 5 years)
2, Accelerated silicosis (high concentrations, symptoms in 5-10 years post exposure
3, Chronic silicosis (low concentrations, symptoms after 10 years)
Discuss pneumoconiosis
Pneumo (relating to the lungs)
Coniosis (dust)
“black lung”, “miner’s lung”, “dusty lung”, “brown lung”
Silicosis and asbestosis are both types of pneumoconiosis.
An interstitial lung disease where dust particles cause fibrosis in alveoli.
What is the IARC?
The International Agency for Research on Cancer
Is silica a carcinogen?
Crystalline silica is a known carcinogen.
Crystalline silica is an IARC group 1 carcinogen (known human carcinogen)
List common materials that contain silica.
Rock and sand Topsoil and fill Concrete, cement, and mortar Masonry, brick, and tile Granite, sandstone, and slate Asphalt (containing rock and stone) Fibrous-cement board containing silica
What are common work activities that expose workers to silica?
Abrasive blasting Jackhammering Cutting brick/tile Grinding concrete Road construction Hauling gravel Concrete demolition Sweeping concrete dust
What legislation governs the safety of silica in the workplace?
- No public safety legislation (as with toxic process gasses)
- General OHS legislation for hazardous material
- Specific legislation in BC OHS Regulation (Part 6) - includes prescriptive legislation.
What did Peter Sandman famously say about risk?
Risk = Hazard + Outrage
If workers are aware of a hazard, and not educated properly, then they will become outraged about it. Risk of worker relations issues.
What basic things does mold require?
Food
Water
Oxygen
Correct temperature
What is mold?
A type of fungus.
-multicellular filaments (hyphae)
[versus single-cell yeasts]
There are many species.
It aids in decomposition of organic material.
Mold can grow on dead organic matter everywhere in nature, but are only typically visible when forming large colonies.
Some mold can remain alive/dormant when conditions are extreme or not conducive to growth.
How does mold reproduce?
Spores are produced, which may be sexual or asexual).
Some spores are hydrophobic, making them proficient at wind dispersal over long periods/distances.
List common molds in Canada.
*Cladosporium
(the black mold usually found around windows/bathrooms)
Aspergillus
Stachybotrys (controversial toxic black mold - debated & rare in Canada)
Penicillium
Trichophyton (athlete foot, ringworm, jock itch)
What is it about mold that can cause disease?
Exposure to partial or whole fungal hyphae
Exposure to mold spores
Exposure to mold by-products (mycotoxins or MVOCs)
{MVOC, Microbial Volatile Organic Compounds}
What is a MVOC?
Microbial Volatile Organic Compound.
Produced as part of metabolism and usually responsible for musty smell.
Can be a respiratory irritant, but usually little more than an annoyance.
Discuss health effects associated with mold.
Most people have no reaction to mold exposure.
The most common health effects of mold exposure are allergic or irritant reactions.
Flu-like sympoms, asthma-like reactions, and skin rashes may occur. Symptoms often resolve with removal of mold.
Fungal infections are possible, usually in immuno-compromised individuals.
Sometimes mold is incorrectly identified as a cause of disease.
List acute and chronic symptoms of mold exposure.
Acute: Fatigue Headache Eye/nose/throat irritation Cough Asthma aggrevation
Chronic: Joint pain Morning stiffness Poor memory and difficult speech Tingling/numbness of skin
Discuss mold overexposure as addressed in BC OHSR.
There are no OEL, therefore no overexposure.
OHS claims for respiratory inflammation due to exposure to fumes/vapours/mists/gasses/dusts/irritating substances that occur within 48-72hrs can be approved.
There are some known allertic alveolitis diseases with specific repeated exposures. (mushroom workers)
Is Canadian OHS law regarding mold prescriptive?
No. Very non-specific, and very performance-based.
Discuss mold investigation.
Primary investigation method is to think about likely locations and visually inspect.
Secondary method, usually not recommended, is air sampling. Context important. Mold in air is considered normal. Source would still need to be found visually.
Describe 4 methods of remediation for mold caused by clean water.
Wet Vacuum & steam cleaning
Damp-wipe Surfaces
-wiping surfaces with water +/- detergent. Scrubbing PRN.
HEPA (high efficiency particulate air) Vacuum
-after fully drying
Discard
-dispose of materials in sealed plastic bags, regular garbage.
What are the two mold common molds in Canada? Why?
Cladosporidium and Penicillium.
Nutrient recycling by decay of organic material. Lots of leaves and organic material to break down, therefore lots of these molds.
What are hyphae?
Multi-celled filaments that make up a mold colony.
When disturbed, hyphae can break and become airborne particulates, which can be allergenic.
What are mycotoxins?
Toxic chemicals produced by fungi. They increase risks to workers.
Discuss primary and secondary methods of mold investigation.
1, Visual - look at likely problem areas first. Identify locations and note colony size.
2, Air sampling. Count spores and identify species.
- does not identify source
- No OEL, therefore hard to compare results
- Snapshot in time, counts often fluctuate over time
What information is needed when determining mold prevention or remediation stratagies?
Clean/dirty water?
Time since water exposure?
(48hrs)
What are the materials/chemicals involved?
Size of mold colony & area affected.
Compare/contrast protective headgear CSA classes G, E, and C.
All CSA Z94.1 headwear is:
- resistant to blunt-force impact
- resistant to penetration by pointed objects
- avoid degradation in heat & bright light
- passively retained on the head
- must identify electrical performance class inside shell
Class C = conductive
Class G = general use (resistance of 2,200 V)
Class E = electrical trades (resistance of 20,000 V)
What are the 7 CSA classes of eye and face protector?
1, Spectacles 2, Goggles 3, Welding helmets 4, Welding hand shields 5, Non-rigid hoods 6, Face shields 7, Respirator facepieces
Discuss CSA grade 1 and 2 protective footwear.
CSA Grade 1 protective footwear provides maximum toe impact protection, with sole penetration protection.
Grade 2 provides toe impact protection (lower level protection than grade 1) and sole penetration protection (equal protection to grade 1)
What is a reasonable process for the selection of high-visibility garments for use in the workplace?
1, Determine the nature of the work/hazards.
(directing traffic under 30kph)
2, Review regulation/standard to determine minimum requirement
Type 1, 2, 3?
3, Consult workers/supervisors to determine most appropriate style
(if multiple types acceptable, which is preferred?), (which colour better, orange vs lime green?), (what about differing weather conditions?)
4, Work with suppliers to source garments that comply with regulations and meet workers needs
What are the CSA Z94.2 HPD classes?
Based on sound attenuation, HPDs are placed into three classes, A, B, and C.
A, attenuates 10dB at 125Hz, up to 33 dB at 8000Hz. 31dB at 1000Hz.
B, attenuates 5dB at 125Hz, up to 23dB at 8000Hz. 21dB at 1000Hz.
C, is not required to attenuate sound until 1000Hz, at which time it must attenuate 11dB, up to 13dB at 8000Hz.
**there are two special extra classes, AL and BL.
These are used for devices that qualify as category A or B AND provide at least 20dB attenuation at 125Hz (low frequency protection)
What is the required process for selecting the class, grade and style of hearing protection for workers?
Bigger is not better. Too much protection interferes with work and reduces compliance. Too little protection, fails to protect.
1, perform noise exposure monitoring to determine hazard.
2, Use standard to select appropriate class/grade of protection.
3, Identify suitable options based on work and workplace (temperature, activities)
4, consult with JOHSC/workers/supervisors for input/preference.
Explain the need for a professionally managed PPE program in the workplace.
The appropriate PPE needs to be identified for the hazards of the work.
PPE can interfere with work and comfort. Use when not needed may reduce compliance.
Workers need to know how PPE protects them, and what the limits are. Otherwise they may think they have more protection than they do.
PPE must be maintained, cared for and replaced to ensure it is functioning properly.
If workers and supervisors are not educated/trained in appropriate selection and use of PPE, then they will not choose to use the appropriate PPE.
What 5 indicators suggest an organizations PPE is not effectively managed?
1, PPE decisions are made by the purchasing department, primarily based on cost.
2, Workers are routinely asked to wear PPE, although risk assessment shows that it is not necessary.
3, Workers have little knowledge about their PPE limitations when asked.
4, There is little evidence of a program for PPE upkeep and maintenance.
5, Managers and supervisors are unaware that there are critical choices to be made in the selection of basic PPE (headgear, footwear)
What are typical PPE requirements in Canadian OHS regulations?
1, Workers may be required to provide PPE against natural elements
2, All other PPE must be provided by the employer, at the employer’s cost.
3, Employers must be knowledgeable about hazards and the range of PPE available. PPE selection must be chosen based on this information.
4, Most PPE must meet CSA standards, or another acceptable standard.
5, Employers require a program for maintenance/repair/replacement of PPE.
6, Employers must educate workers about limitations of PPE.
7, A written PPE program should be developed for all PPE. It is required for certain types of PPE.
List some CSA standards for PPE.
CSA Z94.1 - Industrial Protective Headgear
CSA Z94.2 - Hearing Protection Devices, performance, selection, care, and use
CSA Z94.3 - Industrial eye and face protectors
CSA Z94.4 - Selection, use, and care of respirators
CSA Z195 - Protective footwear
CSA Z195.1 - Selection, care, and use of protective footwear
What are the eight hazards that CSA eye and face protectors protect against?
1, Flying objects 2, Flying particles/dust 3, Molten material and sparks 4, Chemical splash 5, Abrasive blasting material 6, Glare and stray visible light 7, Optical radiation (UV, light, infrared) - moderate reduction 8, Optical radiation - large reduction
What are the 6 hazards that CSA Z195 footwear protection may protect against?
1, Toe impact 2, Sole penetration 3, Metatarsal impact 4, Electrical shock 5, Electrical charge build-up 6, Chainsaw cut
footwear will protect against two or more, but never all of the 6 hazards
What are the 6 hazards that CSA Z195 footwear protection may protect against?
1, Toe impact 2, Sole penetration 3, Metatarsal impact 4, Electrical shock 5, Electrical charge build-up 6, Chainsaw cut
footwear will protect against two or more, but never all of the 6 hazards
How are protective footwear identified?
The footwear must have a sewn on label depicting designated markings that indicate the specific protections.
The same information must be printed on the inside of the shoes/boots.
What is the difference in safety equipment with comparable safety ratings when there is a significant price difference.
The price may indicate additional features, comfort, or durability. It does not indicate that the equipment is more or less protective than a cheaper alternative with the same safety rating.
Should protective headgear (hard hats), and high visibility clothing be worn at all times by all workers on a work site?
Not necessarily. Protective equipment should be worn when indicated by hazard assessments and risk evaluations.
When PPE is worn, it should be worn for a reason and the worker should understand what that reason is and what the limits of the protection are.
What legislation governs PPE?
Provincial OHS regulations usually reference known standards, such as CSA standards. Sometimes regulators will develop their own standards instead of or in the absence of pre-existing standards.
BC OHSR Part 8, Personal Protective Clothing and Equipment
also, work activity specific legislation (such as BC OHSR part 18, traffic control - section 18.9 & 18.10)
What are the WorkSafeBC Standard types of high visibility garment?
Type 1, vest/shirt/similar
Type 2, jacket/coat/coveralls/similar
Type 3, harness/harness affixed to another garment (such as a harness stitched to a vest)
Discuss OHS regulations for HPDs.
All Canadian OHS regulations have similar provisions for Hearing Protection Devices.
HPDs may only be used when all reasonable engineering and administrative controls have been implemented and noise levels remain above exposure limits.
A professional process must be used to select HPD that are appropriate for the amount and type of noise present.
BC OHS Regulation, Part 7
List four CSA Z94.2 recognized HPD devices.
Earplugs
- foam/rolldown
- pre-moulded
- formable
- custom moulded
- semi-insert/canal cap (superaural)
Earmuffs
- headband
- hardhat attached
Helmets (such as for pilots)
How does the CSA assign a class or grade to hearing protection?
The class of a HPD is based on the dB attenuated, based on the sound frequency in Hz. A being the highest protection, C the lowest.
The grade of a HPD is based on the attenuation achieved with 84% of workers (evaluating fit). Grade 0 is the lowest, and grade 4 is the highest protection.
What are the CSA Z94.2 HPD grades?
If 84% of workers, when fitted with the device achieve ≤9dB sound reduction outside, then they device is grade 0.
If 84% of workers, when fitted achieve ≥22dB sound reduction, then the device is grade 4.
Grade 1 is 10-13
Grade 2 is 14-17
Grade 3 is 18-21
How is hearing protection rated in the USA?
Noise Reduction Rating, in dB.
How much noise is OK?
Sound below 70dB may be too low. If overprotection reduces sound to this level, then it may interfere with work.
Ideally, sound levels should be 75-80dB.
Sound greater than 85dB carries an increasing risk of hearing loss.
What is the “permeation rate”?
The rate at which a chemical passes through a glove or clothing material.
What is “breakthrough time”?
The elapsed time between contact with a chemical on the outside of a glove/garment and the time that the chemical is first detected on the inside.
Example, acetone has a fast breakthrough time with nitrile gloves, but a slow breakthrough time with butyl rubber gloves.
Where can an OHS professional find information on the most suitable material for protection against chemicals?
The best information is found on the SDS sheet.
There are also a variety of published guides that can supplement the SDS.
What are the 5 classes of materials for protective gloves/garments?
1, Natural rubber (latex)
2, Synthetic rubber (butyl, neoprene, nitrile, viron)
3, Synthetic polymers (Tyvek, Silvershield, CPF)
4, Polyvinyl alcohol (PVA)
5, Other materials (Polyvinyl chloride, PVC)
What are the 4 main hazard types to consider for protective gloves and clothing?
Chemical hazards
Biological hazards
Physical hazards (temperature, vibration)
Mechanical hazards
Discuss considerations for protective gloves/clothing against biological agents.
Typically gloves/clothing to protect against biological agents are used in medical workplaces. As such, there is a need to protect against bodily fluid exposure and cuts/punctures. There is a need to allow for manipulation of fine instruments.
Natural latex used to be the material of choice, but it is now synthetic nitrile rubber due to people with allergies.
Vinyl is popular as an inexpensive option, although the properties lead to a poorer fit.
Discuss considerations for protective gloves against physical vibration hazards.
Vibration can cause HAVS (Hand-Arm Vibration Syndrome).
Many gloves marketed as anti-vibration do not do what they claim, and some increase risks.
There are standards for anti-vibration gloves, but they are not referred to in any North American legislation (they are in areas of Europe).
Discuss gloves to protect against cuts and abrasions.
Leather, heavy cotton, and mixtures of both are most commonly used to protect against cuts and abrasions.
The standard ‘work glove’.
Stainless steel can be incorporated into gloves to protect more against cuts, particularly with metal work, meet cutting, and other higher risk activities.
Kevlar has become an alternative/popular inexpensive material that protects against cuts and puncture without absorbing a lot of water.
Protective gloves may have grips added, such as dots/strips of neoprene to improve grip. Especially with Kevlar gloves because the material is slippery.
Discuss leg protective devices.
Commonly called chaps, or chainsaw pants.
There is no Canada-wide standard for leg protective devices. BC has it’s own standard in part 8 of the OHSR, which some other regulators recognize.
Chaps often work by containing loosely woven fibers behind a barrier that, when broken, rapidly bind the teeth of a chainsaw while also forming a barrier between the chain and the leg.
What are the four general categories of hazard that respirators might protect against?
Chemical agents
Biological agents
Ionizing radiation attached to particulate material
Oxygen deficiency
What is an APR respirator?
An Air Purifying Respirator uses a filter or cartridge to clean air before it is breathed in.
What are the types of respirator?
APR, non-powered
- half-face
- –filtering facepiece (mask is filter)
- –elastomeric (uses filters/cartridges)
- full-face
- –always elastomeric
APR, powered (PAPR)
- half-face elastomeric
- full-face elastomeric
- hood
- helmet
- loose-fitting facepiece
Air-supplying respirators
- Supplied-air (airline)
- Self-contained breathing apparatus (SCBA)
- Combination, supplied with auxiliary self-contained supply
Escape Respirators
(may be APR or ASR)
Discuss filters and cartridges for respirators.
Filters a made of a fibrous material that traps particles as you breathe. This mechanically filters the air.
Cartridges contain sorbent materials, chemicals, or both.
Sorbent materials (activated charcoal) bind to contaminants to remove them from the air. Chemicals react with specific air contaminants to alter their composition.
Some respirators can be fitted with multiple cartridges for multiple functions.
What is NIOSH?
National Institute for Occupational Health and Safety (US agency)
What respirators are approved for use in BC?
All respirators must be NIOSH approved and unmodified unless they have been specifically approved by WorkSafeBC use.
WorkSafeBC does not accept single-strap “dust masks”. They must all have two or more straps for secure fit.
Discuss particulate filters
NIOSH filter types:
N = not oil resistant R = oil resistant (OK for 1 shift with oil) P = oil-proof (OK for more than 1 shift with oil)
Efficiency: 95 = 95% 99 = 99% 100 = 99.97% (aka HEPA) High-Efficiency Particulate Air filter
List four examples of contaminants where WorkSafeBC requires HEPA filter respirators.
Asbestos
Lead
Hantavirus
Cadmium
What are TWA and ceiling limits?
The ceiling limit is the absolute maximum concentration (ppm) of a substance that a worker may be exposed to.
The TWA, Time-Weighted Average, is the maximum average concentration that a worker may be exposed to over an 8-hour period.
When should an air-supplying respirator be used?
When there are high levels of contaminant.
When contaminants are highly toxic.
When the contaminant has poor warning qualities and end-of-life cartridge indicators for APR are unavailable.
When cartridges/filters are unable to effectively remove the contaminant (nitrogen dioxide, nitric oxide, nitrous oxide)
Discuss respirator Protection Factor (PF)
aka APF, Assigned Protection Factor
NIOSH and ANSI perform standard tests to measure the ability of a respirator to reduce contaminants.
The PF (protection factor) is the ratio between contaminant in exposure air and purified air.
If contaminant is 100ppm, and purified is 10ppm, then the ratio is 100:10, 10:1. PF =10.
If contaminant is 1000ppm, and purified is 10ppm, then the ratio is 1000:10, 100:1. PF =100.
If contaminant is 50,000ppm, and purified is 100ppm, then the ratio is 50,000:100, 500:1. PF =500.
What are the two basic types of respirators?
Air purifying
Air supplying
What are the two basic types of AS respirator?
Airline
SCBA
Discuss regulations for respirators.
Respirators are often highly regulated in provincial OHS regulations. Part 8, BC OHSR.
Respirators must meet published standards, also selection of respirators and it testing must also meet published standards.
There are no Canadian agencies that approve respirators, and NIOSH is usually used.
List the steps to choosing a respirator.
1, Hazard identification
2, Check hazard concentration
3, Compare hazards/concentrations with exposure limits
4, Check IDLH concentration
5, Check hazard properties and select possible respirator types
(eye irritant? skin irritant?)
[use SDS to help]
6, Check APF (assigned protection factors)
7, Compare APF needed, to APF of identified respirators
8, Compare MUC (maximum use concentration) to the contaminant concentration.
9, Identify the general class of respirator required (ASR vs APR)
10, What is the state of the contaminant? (gas/vapour, particulate, both)
11, What are the warning properties of the contaminant? (smell, etc.)
12, Select the appropriate filter/cartridge.
13, Are there any special requirements?
- worker comfort
- work activity needs
- worker with corrective lenses
What is a respirator MUC?
Maximum Use Concentration
Determined by multiplying the respirator’s APF (assigned protection factor) by the TWA.
This indicates the maximum contaminant the respirator is demonstrated to be effective against.
Discuss user seal or fit checks for respirators.
Every time a worker uses a respirator, they should conduct user seal check (aka fit check).
Both a negative and positive pressure test should be performed, unless the respirator resign prevents one of these being done.
Negative Check
Block the valves etc. and inhale slightly. Hold for 10s. Ensure no leaks.
Positive Check
Block valves etc. and exhale slightly. Hold for 10s. Ensure no leaks.
Discuss Mask Fit Testing
Qualitative and quantitative tests possible. Required at least annually.
Quantitative requires special equipment to measure concentrations of contaminant in/out of mask.
Qualitative more common. Three main methods.
1, Odour Test
Banana oil - tests cartridges, not filters
(vapour, not irritating, pleasant odour, easy to use, can be a problem with latex allergy)
2, Irritation Test
Irritant Smoke
(fume, easy to use, highly irritating)
3, Taste Test
Bitrex and Saccharin
(Messy, a test hood is required)
What are the general classes of hazardous energy in the workplace?
Kinetic Chemical Potential Thermal Electrical Radiation
What is de-energization?
De-energization is the process of ensuring that energy from machinery/equipment is contained and unable to be released into a worker that may be working in the normal path of that energy.
What resources should be used when determining whether de-energization or lockout are required for a work process?
1, Regulations
2, Technical manual from manufacturer
3, Input from qualified workers
What is a control system isolating device?
A device that physically prevents activation of a system used for controlling machinery or equipment.
What is an energy isolating device?
A device that physically prevents the transmission or release of an energy source to machinery or equipment.
What is a key securing system?
A system which physically prevents access to keys when locks or positive sealing devices are applied in a group lockout procedure.
What does the term lockout mean?
The use of a lock(s) to render machinery or equipment inoperable or to isolate an energy source in accordance with a written procedure.
What is “maintenance” according to BC OHS legislation?
Work performed to keep machinery or equipment in safe operating condition, including repairing, installing, cleaning, lubricating, and clearing of obstructions to normal flow.
What is “normal production” according to BC OHS regulations? Context, de-energization & lockout.
Work that is routine, repetitive, and integral to the normal use of machinery or equipment for production.
What are the standard rules regarding personal locks?
1, They must be key locks, not combination.
2, Each lock much be individually keyed with only the owner having the key (with possible exception of a spare with supervisor/manager)
3, Most jurisdictions (incl’ BC) require that locks be identified/labelled
4, In most situations, every worker must apply their own lock on machines during work.
What is the standard process for re-energization?
1, The worker who did the de-energization/lockout checks that the equipment is clear and safe of obstruction/workers. The machine is then observed to ensure no person enters the energy path after inspection
2, The worker removes their lock and re-activates the main energy-isolating device.
Who should apply a multi-lock hasp?
The person with the primary responsibility, who performed the five steps of DE/L, should apply the multi-lock hasp and secure their lock in the first position.
What is a multi-lock hasp?
A device that can be used in place of a padlock, which has spaces for multiple padlocks to be applied.
This allows for multiple individuals to each secure a device with their own personal lock.
What are the steps of de-energization and lockout?
1, De-energization
Identify and shut off the main energy-isolating device.
2, Confirm de-energization
Confirm that there are no workers in the path of energy, and then test the equipment to conform that the energy is controlled.
3,Assure continued de-energization
Apply a personal lock.
What is a group lockout procedure?
A procedure that can be used when there are multiple energy-isolating devices that require lockout and there are multiple workers involved.
It reduces the need for excessive numbers of personal locks.
1, TWO qualified workers perform standard DE/L procedures for each device.
2, The keys to the locks are locked in a box, and the box is secured with a multi-lock hasp.
3, Each worker puts their personal lock on the hasp.
4, Each worker removes their own lock when they have completed work and are no longer in the path of energy.
5, When all locks are removed, TWO designated/qualified workers re-energize the devices together following standard procedures.
What should be done if a worker leaves and forgets to remove their personal lock?
1, All reasonable steps must be taken to contact the worker and confirm that they are not in the path of energy.
2, The supervisor may take responsibility for removing the lock, and the lock may be removed in the worker’s absence.
3, The device is re-energized following normal procedures, including confirming that there are no workers in the path of energy.
(this is prescribed in the BC OHSR)
What legislation governs de-energization and lockout?
BC OHS Regulation, Part 10.
Additionally, there are a number of design standards to ensure that equipment has de-energization and lockout design features/instructions.
Discuss why there is a section in the BC OHSR dedicated to de-energization/lockout, and how inspections handle violations.
- Regulators have not found another method to assure the same level of safety
- There is a long history of injuries and deaths where rules were not followed.
- Violations are still being noted during inspections and there is a known gap in education/training/attitude.
If an inspector encounters a violation in BC they will immediately stop work, and issue a penalty to the employer and/or worker.
When the main energy-activating device for a machine is a valve, what is the DE/L proedure?
1, Close the valve
2, Bleed the remaining energy from the system if possible
3, Apply a valve lockout device with a personal lock
4, Confirm that there are no people in the path of energy
5, Test the equipment to confirm de-energization
Who is responsible for the five steps of DE/L in a multi-person lockout?
The person that applies the hasp is responsible for the 5 basic steps of DE/L.
Ideally this person should be one of the most experienced/knowledgeable in DE/L procedures.
The responsibility of re-energization may fall on the last worker to remove their lock, unless there is an employer designated responsible person.
Why are most radiation sources of energy controlled with electrical energy DE/L procedures?
Most sources of radiation require electricity to operate. Electrical DE/L eliminates the possibility of radiation.
-This is applicable to ionizing and non-ionizing radiation.
How are plugged in machines typically managed for DE/L?
The machine is unplugged and male end of the cable kept in full sight/control of the worker.
This is acceptable as DE/L without the use of physical lockout.
If the male-end of the cable is not under full sight/control of the worker, then standard lockout procedures are required.
What are the five basic steps of DE/L?
1, Identify the machinery/equipment that requires DE/L
2, Shut off the machinery/equipment, and wait for all moving parts/process to come to a complete stop.
3, Locate and de-activate the main energy-isolating device
4, Apply a personal lock
5, Test the effectiveness of the DE/L (try to start machine)
What is voltage?
Voltage is the potential difference between a conductor and the ground.
It is the electrical pressure, or power.
Volts.
What is current? Context, electricity.
Current is the quantity or volume of electricity.
amps.
Name the regulations, standards, and codes governing the installation and design of electrical conductors and electrical powered equipment.
Provincial electrical codes and regulations are usually based on the Canadian Electrical code, and CSA 22.1, 22.2, and 22.3.
In BC this is the Electrical Safety Act, and Electrical Safety Regulation
Additionally, OHS regulations usually cover some electrical safety. There is often overlap between the legislation.
BC OHSR Part 19. Electrical Safety
The BC OHSR references the Electrical Safety Regulation.
What regulations govern work practices on and near energized equipment?
1, Provincial electrical code and regulations
(usually based on the Canadian Electrical Code, CAS 22.1, CAS 22.2, CAS 22.3)
In BC this is the Electrical Safety Act, and Electrical Safety Regulation
2, Provincial OHS regulations associated with electrical safety
In BC, this is the BC OHSR Part 19.
There is often overlap between electrical safety and OHS safety regulations.
What is GFCI? Context, electrical safety.
A Ground Fault Circuit Interrupter is a device that monitors the current in the hot and neutral wires of a cord. If there is 5 mA or more leakage, then the GFCI will cur the power.
A GFCI is not the same as a circuit breaker or fuse in an electrical panel. These trip when the current through the wire is too high, typically 10-30 A. At 10 A, the current is high enough to cause electrocution.
What is electrical resistance?
Electrical resistance is the amount that a material reduces the flow of electricity.
Ohms.
What is ohms law?
V = I x R (Voltage = current x resistance)
Variation
I = P ÷ E
V, voltage I, current (intensity) R, resistance P, power (watts) E, voltage (electromotive force, older notation than V)
What is considered to be a low voltage line?
BC OHSR, part 19 = 31-750 is low voltage.
What is high voltage?
BC OHSR, part 19 = 750+ volts is high voltage.
What is AC/DC?
AC = alternating current DC = direct current
Frequency of AC is measured in Hertz (Hz), cycles per second. Always 60Hz in Canadian homes.
Discuss electrical shock injuries.
Injuries caused by the bodies own electrical system being overloaded.
- Muscle damage from severe contraction
- Damage to non-muscle tissue from excess muscle contraction
- Cardiac arrhythm or arrest
Discuss electrical burns.
Electrical resistance converts electricity into heat. Burns can occur at entry site, exit site, or anywhere between.
An arc may be created resulting in arc or flash burns to the skin or eyes.
What are indirect electrical injuries?
Injuries incurred by electrical shocks other than shock and burn injuries.
For example, a fall or bring thrown from the electrical source.
What is the CSA?
The Canadian Standards Association
How can a professional design safe work practices for work on or near electrical systems?
1, If possible, de-energize the system before work
2, If possible, reduce the energy in the system
3, Only permit qualified workers to work on the system
4, Work with appropriately qualified workers to develop safe work practices
How can an OHS professional ensure that work on or near electrical energized equipment meets due diligence?
1, Know the regulations for the jurisdiction, including what is accepted as a qualified worker for the jurisdiction.
2, Confirm the qualifications of all workers.
3, Ensure that at least 1 qualified person assists in the writing of safe work procedures.
4, Limit risk by limiting the numbers of qualified and non-qualified workers permitted in the work area.
What is the cause of most accidental high voltage deaths & injuries?
Accidental contact with high voltage powerlines.
Investigations typically find:
- Work was usually near the power line and not on the power line
- Lines carried 25kv or less (standard commercial lines) and not 60-500kv lines (main, high power lines)
- Workers were aware of risk but didn’t implement appropriate controls
- Workers assumed that the power lines were insulated or protected in some way
- Additional workers were injured attempting rescue
What is the touch potential?
Touch potential is the potential difference in volts between a power source and the ground.
If a circuit contact is made between the two, then the electricity will travel along the circuit.
Example, power lines where a person touches the line and the pole supporting the line, completing the circuit to the ground.
What is step potential?
Touch potential is the potential difference in volts between two points on the ground.
When electricity is travelling to the ground (down power lines), the ground around the source becomes electrified. Further away from the source, the voltage gradually decreases. If a person stands with one foot on ground with 5kv, and another foot on ground with 4kv, then 1000v will travel through the worker to move from the high to low voltage areas.
What are limits of approach?
Prescriptive legislation that is generally found in all OHS legislation. It dictates the minimum distance workers or equipment may be to an electrically energized source. (with exceptions)
Example, BC OHSR Part 19, section 19.24.1
750V to 75kV = 3 meters
75kV to 250 kV = 4.5 metres
250kV to 550kV = 6 meters
What should a worker do if operating equipment that comes into contact with powerlines?
1, Remain in vehicle
2, Attempt to move vehicle to break contact
3, Warn other workers to maintain limits of approach to vehicle
4, If vehicle cannot be separated from powerlines, then remain in vehicle until help can be organized
5, If the worker must leave the vehicle (fire), then jump with feet together being careful not to stumble. Goal is to avoid touching ground and vehicle at the same time.
6, Keep feet together and carefully hop until out of limit of approach
Discuss accidents from low voltage electricity
Injuries and deaths from low voltage equipment are high. Possibly due to:
- uneducated people think that low voltage means low danger
- uneducated people may work on low voltage equipment at home, and so think that it is safe
- workers may have seen qualified persons working with energized low voltage equipment and think that they know all the hazards
- Standards and regulations for design and installation of electrical equipment in Canada are high. As such, many people do not hear about low-voltage accidents
- Many workers think that low voltage equipment has protective design features to keep them safe.
What should be done if work must occur within the limits of approach?
There is highly prescriptive legislation that follows the hierarchy of controls when work must be conducted within the limits of approach.
This includes de-energization when possible, and paperwork when it is not. WorkSafeBC must be notified, hazards must be clearly marked and a watcher is necessary.
What three steps can be taken to ensure that portable electric-powered tools do not become an electrocution hazard?
Only permit approved electrical tools and extension cords to be used.
Ensure that appropriate grounding is in place for all electrical tools and extension cords.
Use a ground fault interrupter, especially in wet locations.
How can you ensure that portable, electrical tools and extension cords are safe for use in the workplace?
Tools should be double insulated, ensuring that the electrical components are isolated from the case. This should be stated on the label with a symbol of a square within a square.
While OHS regulations do not require double insulated tools to be grounded, many are and best practice is that they should be.
Extension cords should be CSA approved for outdoor use.
How can grounding be tested in an extension cord or a receptable?
1, A polarity tester can be plugged in and light codes checked.
2, A multimeter can be used to test continuity.
What is the difference between a circuit breaker and a GFCI?
A circuit breaker is designed to reduce the risk of fires, and stops current that is too high. A high current can generate heat and cause a fire.
Typically 10-30 A.
A GFCI trips when there is a leakage of current from the circuit. This is designed to reduce the risk of electrocution.
Typically 5 mA.
What is the ripple effect?
When equipment grounds a high voltage line, the current travels into the ground and spreads out from the grounding. The voltage gradually decreases in concentric circles around the grounding point, like ripples in a pond when a stone is dropped in.
These ripples can create step potentials if someone is walking or an object connects two sections of ground that have differing voltages.
What 4 questions can be used to understand the product movement/transportation system being used in a warehouse?
What type of product packages are being handled?
What is the direction of transport in the facility?
What is the mode of transport?
What transport equipment is being used?
List 7 common material handling tools.
Hand trucks Pallet Jacks Lift Tables Conveyors Overhead Rail Systems Stair Climber Vacuum Lifter
Are back belts PPE for lifting?
No.
There isn’t strong evidence to indicate whether back belts make a difference in the risk of injury. As such, WorkSafeBC does not consider them to be PPE.
What are the most common styles of storage racks?
1, Pallet Racks
Simple shelving designed for pallets or large units of materials
2, Drive-In/Drive-Through Racks
Large racks intended for use with a lift truck (or similar)
3, Cantilever Racks
Bracket-like arms that long items can be placed on.
4, Special Racks
Usually an adapted version of one of the other systems.
What standards are relevant in storage rack systems?
Most OHS regulations and building codes require RMI/ANSI standard steel racking.
ANSI usually adopts RMI standards for steel storage racks.
RMI is the Rack Manufacturers Institute.
What 4 critical safety items should be considered with storage racking?
1, RMI/ANSI approved or another acceptable standard.
(Rack Manufacturers Institute, American National Standards Institute)
2, Rack components strong enough for intended load.
3, Rack height is stable.
4, Racks guarded against contact with machinery (such as damage from lift truck collision)
What is ANSI?
American National Standards Institute
What is the RMI
Rack Manufacturers Institute
Contrast storage shelving vs storage racks.
Storage shelving is for smaller/lighter materials.
Racks are for larger/heavier materials.
What are the 4 basic configurations of storage shelves?
1, Open shelves
- Sides and back of shelving is open
- braces may help to stabilize
- floor mounted
2, Closed shelves
- sides and back panels present & add stability
- floor mounted
3, Ledge Shelves
- may be open or closed
- 2 or more units, where the lower is deeper resulting in a ledge/counter space
- floor mounted
4, Counter shelves
- shelving mounted on a counter instead of the floor
- may be any other type (open, closed, ledge)
What standards are relevant in storage shelving systems?
SEMA (Storage Equipment Manufacturers Association) & ANSI produced two standards.
1, industrial steel shelving
2, metal-wood shelving
What is an AS/AR system?
Automated Storage/Automated Retrieval system.
What is an AGV?
An automated guided vehicle.
Used in highly automated facilities to store and retrieve materials.
What safety considerations are generally important when working with AS/AR systems?
Automated systems are powered, and as such introduce the hazard of workers coming into contact with the energy of the system.
Effective guards are required to protect workers from accidental contact with system energies.
Effective de-energization processes are necessary.
What safety items should be inspected on racking/shelving systems?
- Conformation to design standards
- Load capacity vs actual; load
- Bracing/stabilization components in place and good repair
- Structural components in place and in good repair
- End/corner guards are in place
- If evidence of damage to guards, then review worker training (lift trucks)
- Materials stored is stable
Describe the Recognition — Evaluation — Control model as it is applied in risk assessment and hazard control in the workplace
The simplest approach to H&S issues.
Recognize a problem, evaluate it, control it.
Recognition:
- Own professional experience/education
- Stastistics
- Consultation with workers, supervisors, managers
- Regulations, guidelines, standards
Evaluation:
May be simple or more involved.
(evaluating need for guard on sawblade is fairly simple)
(evaluating chemical exposure hazards can be more involved)
Control: Order of preference (the control toolbox) 1, Prescribed regulation 2, Required standards 3, Best practices 4, Other control practices
Explain the rationale behind the hierarchy of controls: Engineering — Administrative — Personal Protective Equipment
Most to least effective controls.
Training is essential for controls to be effective.
Outline the method for selecting appropriate hazard controls given either prescriptive or performance-based OHS regulations
Order of preference (the control toolbox)
1, Prescribed regulation
2, Required standards
3, Best practices
4, Other control practices
————————————————————————————
Identify required controls. Then Look at published best practices. In the absence of sufficient controls from the above, look elsewhere such as professional training and professional organization recommendations.
Due diligence requires that these all be considered when developing controls.
Define the term hazard.
A condition or situation that exists within the working environment that is capable of causing an unwanted release of energy resulting in physical harm, property damage, or both. More simply, a workplace hazard is a dangerous condition, whether potential or existing, that can cause physical harm.
Define the term risk
The likelihood or possibility of hazardous consequences; the probability of a loss producing event. Therefore, a work process can be at once both highly hazardous and very low risk, if it has been correctly recognized and the hazard effectively controlled.
What is a standard?
A “standard” is a document that is written by a group of experts in the subject matter. The standard is then a consensus document of the standard way in which something should be done according to those who should know best.
What are the three categories of engineering controls?
Elimination
Reduction
Ventilation
Explain significance of maintaining workplace sanitation.
Unclean facilities can be a health hazard to workers (food health etc.).
Poor sanitation is an indicator of employers safety attitude. Good sanitation demonstrates value to workers.
Unclean workplaces are a red flag to OHS regulators suggesting fundamental OHS management problems.
Discuss importance of personal facilities (showers, change rooms) in preventing movement of workplace contaminants outside the workplace.
Many studies demonstrate measurable levels of chemical/biological agents in the homes of workers. These are usually transported on clothing and in hair.
OHS regulations generally include provisions that when employer supplied clothing is provided, the following must also be provided:
1, Suitable location for storage of street clothes.
2, Suitable facilities for changing in/out of street clothes.
3, Special storage/change arrangements for contaminated work clothing.
Where contaminated work clothes are an issue, the following is a common setup:
Antiroom - remove contaminated clothing
Washroom - shower
Clean room - put on street/clean clothes.
Discuss regulatory and standard requirements for emergency showers and emergency eyewash stations.
There are no Canadian standards for emergency showers. Regulation usually references American standard.
Emergency showers must:
- Have simple controls that can be operated by a semi-incapacitated worker.
- Be close to work processes, and able to resist environmental factors (prevention of freezing if in cold climate)
- Immediately provide adequate water at appropriate temperature for a guaranteed length of time.
There are no Canadian standards for eyewash stations. American standard is usually referenced in regulation.
Self-contained 1L eye wash stations fail to meet ANSI standard (1.5L/min for 15 minutes)
List three reasons an OHS professional should spend an appropriate amount of time dealing with sanitation and basic maintenance.
- Workers see basic housekeeping and it will impact their impression of the workplace and employee-management relations
- A good indicator of systemic OHS problems. Often used as an indicator for inspectors
- Important for hygiene. Worker food safety, and prevention of contaminants taken home.
What are common reasons workers may not take precautions seriously with regards to sanitation and bringing contaminants (eg lead) home?
- Facilities not available
- Facilities not readily available
- Not enough facilities
- Unclean facilities
- Workers not aware of benefit
Why should lunchroom sanitation be maintained?
- Risk of foodborne illness. This is a compensable disease
- Encourages overall concern for sanitation and maintenance
- Possible risk of contamination by workplace chemicals/hazards
- Worker-employer relationship. Condition of lunchroom demonstrates value of workers.
What does an ANSI-compliant emergency shower require
- High flow rate
- Instant method to turn on and remain on
- Hands free operation
- Immediately available tempered water
What should be checked as part of monthly eyewash inspection?
- Access
- Signage
- Water availability & flow rate
- Water temperature
- Unit must be flushed to ensure sanitation
Describe the US National Safety Council’s model for safety through design.
US National Safety Council - NSC
1, Design for minimum risk
2, Incorporate safety devices into design
3, Provide warning devices
4, Develop safe work practices and procedures
5, Use PPE
List the model Canadian national codes that would be of interest to the OHS professional.
CCBFC (Canadian Commission on Building and Fire Codes) a division of the National Research Council of Canada develops and maintains:
- 1, National Building Code of Canada
- 2, National Fire Code of Canada
- 3, National Plumbing Code of Canada
4, National Farm Building Code of Canada
5, National Housing Code of Canada
6, Model National Energy Code of Canada for Houses
7, Model National Energy Code of Canada for Buildings
Note: model codes are not law. Provincial jurisdiction. These are guides that a federally produced for provincial consideration.
Discuss the process by which model codes and design standards become law in provinces and territories.
Province/territory considers model codes (such as written by CCBFC or CSA).
Model code can be adopted, or modified/enhanced.
Examples: Electrical installation and equipment design Elevators Boilers and pressure vessels Pressure piping
The province then develops method of enforcement. BC has Technical Safety BC operating under Safety Authority Act and Safety Standards Act:
- electrical installation
- Elevating devices
- Natural gas installations
- Boilers and pressure vessels
- Mechanical refrigeration systems
What sections of the National Building Code of Canada (2015) are most important to OHS professionals?
Part 1: General Requirements
Part 3: Fire Protection, Occupant Safety, and Accessibility
Part 4: Structural Design
Part 6: Heating, Ventilating, and Air-Conditioning
What is the modern role of each layer of government in safety through design?
Federal - develops model codes
Provincial - adopts laws, often based on model codes
Municipal - usually inspect and enforce provincial laws
Define light
Light is a form of nonionizing radiation. It is in the portion of the electromagnetic spectrum that is visible to the human eye.
400-700nm
Define Lamp
Any device that transforms electricity into light.
Define luminaire
A luminaire is a complete lighting unit, including a lamp.
A luminaire is a device that produces, controls, and distributes light.
What is the difference between luminance and illuminance?
Illuminance is the measure of the amount of light falling on a surface.
Luminance is the amount of light being reflected from a surface.
Describe common lighting metrics.
Standard measurements of illuminance is in lux.
USA also uses older measurement of footcandles.
The measurement of luminance is candela per square meter (cd/m2)
What are the three most common types of emergency lighting?
Unit equipment
Self-contained unit with rechargeable battery and lamp. Mains power charges battery, and unit activates when power is off. Lamp is special incandescent (shorter life, greater output).
Unit Inverters
Similar to Unit Equipment, but uses an inverter to power fluorescent tubes.
Central DC and Inverter Systems
Batteries are stored in a central location and provide power to numerous lamps in event of power failure.
What is the brightness ratio?
The radio of luminance of one surface and the luminance of a second surface.
If one surface has markedly greater luminance than another, then the brightness ratio is high.
What is the contrast ratio?
The contrast ratio is the ratio of luminance of an object (or task) versus the luminance of the immediate background.
A white object with a white background has a contrast ratio of 1.0.
A white object with a black background has a contrast ratio greater than 1.0. The white object has more luminance.
What is the reflectance ratio?
The ratio of an objects luminance versus it’s illumination.
A reflectance ratio of 0.6 means that 60% of the light (from illumination) is being reflected.
What is glare?
Glare is an excessive brightness that causes loss of visual performance or eye fatigue.
Glare can be come from luminaires or from reflected light.
How is visible light typically measured in OHS?
A light meter (photometer or luxmeter) measures illuminance and can be used to estimate luminance, contrast ratio, and reflectance ratio.
Special meters are required for accurate measurements of luminance, contrast ratio, and reflectance ratio.
Discuss incandescent lamps
A filament in an inert gas or vacuum.
Inexpensive overhead Easy to handle & use Instant start No ballast required Come in various shapes
Poor energy efficiency
Short life (including “long-life”)
Produce heat
Discuss fluorescent lamps.
Electricity converted into UV light in tube covered by fluorescent material. Material fluoresces when exposed to UV light.
Often tubes contain mercury to increase UV production and therefore greater fluorescence.
High energy efficiency Low heat output Relatively long life Available in various shapes/sizes Can produce a wide range of light spectra
High initial cost
Requires a ballast
Not usually instant starting
Special disposal needs (mercury)
Discuss HID lamps.
High Intensity Discharge lamps look like incandescent lamps, but function differently.
High energy efficiency
Very long life
Large sizes for large area illumination
Long warmup times
High initial cost
Disposal issues
Often give limited spectrum lighting
Discuss LED lamps.
Light Emitting Diodes use semi-conductors and reflective materials.
Inexpensive Extreme long life Resistant to damage (motion/vibration) Extreme low heat output High energy efficiency Highly visible light
Impractical for lighting large areas
Does not produce significant illumination distant to the lamp
Produces a harsh/bright light
What are reflectors?
Reflectors are highly reflective devices often used in luminaires to redirect light.
These are commonly used in pot lights and floodlights.
What are refractors?
Refractors are lenses of glass or plastic that refract light to a desired direction.
Office fluorescent lighting and warehouse HID systems often use refractors.
What are diffusers in the context of lighting?
Diffusers are opaque glass or plastic sheets that scatter light in many directions.
They are typically used to spread out light that comes from high luminance lamps.
What are bafflers and louvers?
Bafflers and louvers scatter light in many directions in a way that breaks up the images of the lamp to reduce glare.
Often office florescent lighting have bafflers and louvers to reduce monitor glare from the lamp.
What are the IESNA principles of security lighting?
Illuminating Engineering Society of North America
1, Integrate light into the total security system.
2, Illuminate people and places to allow observation and identification.
3, Use security lighting to deter criminals.
4, Reduce fear of crime by enhancing the perception of security.
What references should be consulted to determine minimum illuminance for a workstation?
IESNA recommendations
Building Codes
OHS Regulation
What are basic operational testing and troubleshooting techniques that can be applied to local exhaust ventilation systems?
Do workers know how to properly use the system?
Are air contaminants being effectively drawn into the hood?
Are air contaminants being effectively moved through the ductwork?
Is the air cleaner working efficiently?
Is the exhaust air being efficiently moved away from the building?
What is a Local Exhaust Ventilation system?
An LEV is a system that captures, contains, and removes air contaminants near their source.
Examples:
Laboratory fume hood, kitchen grease canopy, spray paint booth.
What is a GV or DV system?
A General Ventilation or Dilution Ventilation system is a system to supply and exhause large volumes of air to dilute air contaminants in a large, low risk environment.
Typical office HVAC systems are examples of GV/DV systems.
What are the basic components of an LEV?
Hood - surround and capture contaminants near source
Duct - Transport contaminants
Air Cleaner (optional) - Remove contaminant from air
Fan/motor - Provides motion to air in system
Exhaust stack/vent - air exit point
Replacement air source - to replace air removed from work area
What happens if the duct velocity in a woodworking shop dust extraction system is not maintained?
Wood dust may accumulate in the ductwork, this will decrease the extraction system efficiency and pose a fire hazard (combustible wood dust).
What happens if the face velocity in a kitchen range hood is not maintained?
Nuisance odors, smoke, and grease will accumulate. These may present a health, slipping, and fire hazard.
What is the most common and correct purpose for using a dilution ventilation system?
To provide thermal comfort and nuisance odour control.
Define the following in the context of a DV system.
Outdoor air
Supply air
Return air
Outdoor air is untempered and unfiltered air from the outdoors that it drawn into a DV system.
Supply air is tempered and filtered air that is provided by the DV system to the workspace.
Return air is the air returned from the workspace to be exhausted or re-used as part of the supply air.
Why shouldn’t a DV system be used to control air contaminants in the workplace?
It may not provide adequate dilution of a contaminant before it reaches a worker, and contaminated air may be drawn through breathing zones of more workers prior to being removed.
When could a DV system be used for air contaminant control?
When small quantities of low toxicity and low fire hazard contaminants are released into the workspace at a known/uniform rate.
When there is sufficient space between the contaminant source and the worker’s breathing zone, so that effective dilution has occurred by the time workers are exposed.
When contaminated air does not need to be cleaned and the air does not produce other issues (such as corrosion of surfaces).
What observations/measurements can be used at the hood of a LEV system?
Visually assess positioning in regard to contaminant source and worker location.
Use a smoke tube to visualize the capture zone.
Take a face velocity measurement.
What are four common designs of hood in a LEV system?
Plain or flanged (round, rectangle, square)
Slot (plain or flanged)
Booth
Canopy
What might happen if ducts in a LEV system are undersized, rough textured, or have excessive bends?
Inadequate duct velocity (therefore inadequate face velocity)
Accumulation of contaminants in ductwork
Turbulent and inefficient airflow
Noise
What happens when LEV vents/exhaust stacks are improperly designed or positioned?
Contaminants may be re-introduced into the workplace.
Contaminants may ne introduced into other work areas.
List the 6 main components of a standard lift truck.
Overhead Guard
(protects against falling objects and rollovers)
Seat
(seatbelt +/- other restraints, protect against rollovers)
Counterweight
(Added weight to counterbalance the lifted load)
Capacity Plate
(information on the trucks capacity)
Mast, Load Backrest, and Forks
(lift and support the load)
Tilt, Lift, and Side Shift Controls
(allow for safe/secure lifting/carrying)
What are the most common lift truck accident types?
Trucks falling from loading docks
Trucks tipping or losing load on an incline
Trucks tipping when overloaded
Contact with bystanders, other trucks, or equipment/structures.
What four components are required in a powered industrial truck safety program?
1, Trucks operated must meet design standards.
2, Trucks must be operated in accordance with manufacturer instructions AND safe work practices that conform to the standard.
3, Regular inspections are necessary as specified in design standards and manufacturer documents.
4, Operators must be competent.
Discuss lift truck training in BC
Training is required to operate a lift truck. Certification is not required.
Training must meet CSA standard, but can be offered by in-house trainers or external trainers.
Training is required every 3 years, with additional training and supervision as appropriate.
List 6 items that lift truck operators must be tested on in their classroom/knowledge test.
Legislation and regulations applicable to the operation of lift trucks
Lift truck features
Stability
Capacity plate
Preoperational inspection
Start-up
Traveling, with and without a load
Pedestrians
Load handling
Ramps and grades
Personnel lifting
Elevators
Workplace specific hazards
Shutdown
Refueling/recharging
List 6 items that lift truck operators must be tested on in their operation/practical test.
Preoperational inspection
Start-up
Travelling, with and without a load (including pedestrian safety)
Load handling
Driving on ramps and grades
Personnel lifting
Using elevators
Shutdown
Refueling/recharging
What four components are required in an elevated work platform safety program?
1, Elevating platforms operated must meet design standards.
2, Elevating platforms must be operated in accordance with manufacturer instructions AND safe work procedures that conform to the standard.
3, Regular inspections/maintenance are necessary as specified in design standards and manufacturer documents.
4, Operators must be competent.
Discuss classifications of elevating work platforms.
There is no standard classification system for elevating work platforms. However…
MOVEMENT METHOD
- Manual
- Self propelled
- Truck-mounted
LIFTING MECHANISM
- Boom
- Scissor
- Other
CAPACITY
- Single occupant
- Multi-occupant
What standards are available for elevating work platforms?
There are many design standards for elevating platforms depending upon the type of platform.
There are 7 or more CSA and ANSI standards for elevating work platforms.
What are the major hazards of elevating work platforms?
Tipping and rolling when in motion.
Operator falling from platform.
Crushing and shearing injuries when operator or bystander is caught in moving parts of the platform.
Discuss manuals for elevating lift platforms.
The BC OHSR requires that the operation manual AND maintenance manual from the manufacturer be available for workers at the workplace.
If either of these is not available, then the equipment may not be used until it is obtained or written instructions are provided by a professional engineer.
Discuss fall protection with elevated platforms.
In almost all circumstances, fall protection is required when working on an elevated platform. Anchors must meet specifications.
Discuss prevention of tip/roll hazards with elevated work platforms.
If platforms are not designed to be moved with an occupant, then they must be secured against movement before use.
If platforms are intended to be moved with an occupant, then there are prescriptive regulations on the method of movement based on intended design, base dimension and platform height.
Discuss elevating lift platform controls.
Controls must be clearly identified.
Controls must be “hold-to-run”.
Be protected against accidental operation.
Be within reach of operator
Have a clearly labelled, red stop button.
Have an overriding lowering control available to operator.
What are the most common causes of accidents when work platforms are suspended from a crane or hoist?
Inadequate design/construction.
Inadequate attachment of platform to crane or hoist.
Workers not wearing fall protection equipment.
What are the 5 basic requirements found in most OHS regulation regarding fall protection?
Work done over a certain height requires fall protection.
Guard rails are first choice.
When guardrails are not practical, fall restraint must be used.
When fall restraint is not practical, fall arrest systems must be used.
All workers at risk of falling must be trained and supervised.
What is the hierarchy of fall protection?
Elimination of fall hazard. Guardrails or equivalent. Fall restraint. Fall arrest. Control zone.
Guardrail regulations are highly prescriptive. What 3 basic concepts are ensured with the regulations?
STRONG/HIGH/SUBSTANTIAL
guardrails should be strong enough to resist a stumbling worker
guardrails should be high enough to act as a barrier to an stumbling worker
guardrails should be substantial enough to prevent a stumbling worker from slipping between parts.
What is the BC OHSR guardrail height requirement?
102-112 cm.
What is the BC OHSR guardrail height requirement?
102-112 cm.
Discuss fall protection systems
fall restraint & fall arrest.
Must…
-be inspected by qualified person before each shift.
- be kept free of substances and conditions that contribute to deterioration
- be maintained in good working order
- consist of compatible/suitable components
- be sufficient to support the fall restraint/arrest forces
- meet and be used per CSA or ANSI standards from time of manufacture
- be removed from service after arresting a fall
- not be returned to service after removal until recertified by manufacturer, authorized agent, or professional engineer.
Discuss fall restraint.
Fall restraint is a type of fall protection that ensures a worker falls no further than the level that they are working on.
Some regulations require that system minimizes falls to 30cm or less (1ft).
There are various of fall restraint systems, but they must still meet CSA standards.
Discuss fall arrest systems.
Fall arrest systems stop a falling worker before they reach the ground.
Systems must meet CSA standards.
The MAF (maximum arrest force) must be less than 8kn and should be less than 4kn. Most fall arrest systems require shock absorbing technology to achieve this.
Full body harnesses should be used to distribute forces across the body instead of being focused in one area.
Discuss fall arrest systems.
Fall arrest systems stop a falling worker before they reach the ground.
Systems must meet CSA standards.
The MAF (maximum arrest force) must be less than 8kn and should be less than 4kn. Most fall arrest systems require shock absorbing technology to achieve this.
Full body harnesses should be used to distribute forces across the body instead of being focused in one area.
Lanyards may be attached to an anchor or a horizontal/vertical/retractable lifeline.
What are the typical components of a fall arrest system?
Full-body harness
Lanyard or restricted length, with shock absorbing elements
Adequate anchor point.
What are the typical components of a fall restraint system
- full body harness
- lanyard of restricted length
- adequate anchor point
Discuss anchors for fall-protection systems.
Temporary fall-restraint anchors must have a capacity of 3.5kN or four times the weight of the worker.
Temporary fall-arrest anchors must have a capacity of 22kN or two times the maximum arrest force.
Permanent anchors for restraint or arrest must have a capacity of 22kN.
All persons connected to an anchor must have an independent attachment.
What is a swing fall hazard?
A swing fall hazard is a hazaqrd that would cause a person to swing and potentially strike objects in the event of a fall.
These are often ideal locations for anchor points.
Risks are reduced by minimizing lanyard lengths and advising workers to work closely to their anchors.
Discuss lifeline systems.
When workers need more mobility than a fixed anchor provides, a lifeline can be used.
Horizontal lifelines are attached at two ends and the attachment can move freely along the line.
Vertical lifelines are attached at the top, and hang down. The worker is attached to the vertical line with a rope grab, which locks in place when a fall occurs.
Permanent lifelines must be certified by a professional engineer.
Temporary lifelines must be made for purpose, used following manufacturer instructions, installed following written instructions from a professional engineer, and meet requirements of regulatory body.
What are control zones and safety monitors in the context of fall protection.
Some employers (typically roofing industry) argue that the hierarch of fall protection is not practical for their work. (many workers, tangling lines, work at roof edge, processes that damage fall protection equipment)
Some jurisdictions permit control zones and safety monitors as an alternative method of fall protections.
Designated area of higher fall risk (at least 2m from edge), flagged and monitored by a worker that alerts others to fall dangers.
Which part of the BC OHSR covers fall protection?
Part 11.
Discuss fall protection plans.
Most regulators require written fall protection plans.
BC requires written plans for
