Units 4 And 3 Flashcards
Explain the concept of WEL's How they are set? Under what Leg Two Units of measurement Two Reference periods What is a wel (def) Status and use of EH40
Oels are standards set for exposure to particular health hazards above which employers must not be exposed. Wels are the legal standards for substances set by coshh. Lead and asbestos have their own oel under separate regs clar and car
Wels are established by the ACTS advisory committee for toxic substances. And they are set at a level where no adverse effects on human health would occur. ACTS establish the dose/ response relationship.
The two units of measurement are
PPM gases and vapours
Mg/m3 particles
Two reference points are
Twa 8 hr period Ltel. Control harmful substances in the body, control conditions that would enhance disease.
Twa 15 min Stel. Control high concentration of of a contaminant over short period of time.
Maximum concentration of an airborne substance, averaged over a reference period to which employees maybe exposed.
Gives advice on exposure limits, expressed as concentrations, to which airborne substances should be controlled in workplace.
What is the role of the occupational hygienist and what will the level of competence required depend on ?
PicketM
Identification:- identification of the health hazards eg noise, vibration, toxic chemicals.
Measuring:- measurement of exposure levels and hazard data collection eg dosimeters
Evaluation:- evaluate the risks by comparing data against published data and legal standards eg eh40 and wels
Controls:- identification and implementation of controls to reduce risks, evaluate and control.
Level of competence will be based upon
Knowledge
Experience
Certification
Member of professional organisations.
Safety practitioners maybe involved in the management of occupational hygienists. What should be checked ?
What is the effective strategy for monitoring hazards under HSG173
A appropriate strategy and method of sampling was used
The equipment was, tested, maintained and calibrated.
The tests were carried out in real world conditions. Time place duration etc
Results correctly evaluated against legal standards.
Initial Survey-
Gather info
Simple qualitative tests
Basic survey-
Worst case first
Personal sampling
Static sampling
Detailed Survey- Carcinogens, mutagens Exposure is highly variable Initial appraisal indicates close to WEL Cost of additional controls need to be evidence
What is the HSE MDHS series ? And what types of tests are used ?
Methods determining hazardous substances. A set of detailed descriptions for approved sampling and analytical methods.
Direct reading instruments
Chemical reactions designed to produce a colour change
Electrical detection
Physical methods based absorption of ultraviolet or infrared radiation.
Stain tube detectors
A known volume of air is drawn over a chemical reagent supported in a glass tube.
The contaminant reacts with the reagent and the length of the stain is proportionate to the contaminant.
Asbestos
Downward facing cowled sampler head. Amount of asbestos collected is quantified by counting fibres by phased contrast microscopy PCM
Passive detectors
Employ absorbent material to sample concentrations of airborne pollutants without using pumps to draw air.
Badge type samplers
Tube type samplers
Active samplers
Liquid or solid sorbents
Air is pumped through a tube containing active charcoal.
What is the requirement for health and medical records and under what leg must they be kept ?
Health records needs to be kept for as long as the employee is under health surveillance. They must be kept for 40 years.
HR do not contain any confidential clinical details, kept by employer
MR include medical info
Held by doctor or nurse
Can only be released by written consent of individual.
How are biological samples taken ?
What does biological sampling indicate and when are they useful ?
What are the adv and dis of Biological monitoring?
Blood, urine, breath or any combination
Indicates how much of a chemical has entered a workers body, (rather than how much was in the air that may have been inhaled)
Useful when:-
Absorption is likely through the skin or ingestion rather than inhailable.
Valid laboratory methods to identify metabolites in the body
References values available for interpretation of results
PPE used as a significant control
Advantages:-
Demonstrate effectiveness of PPE
Individual exposure measures by all routes of entry
Identifies what has been absorbed into the body
Demonstrates effectiveness in control
Reassurance to workers they are individually monitored.
Dis
May require sample of blood so physicians or nurses required
Measurements relate to individuals so confidentiality must be observed
Individuals may suffer adverse effects below the standard.
BMGV’s :- derived by HSE and published in EH40.
BMGV’s do not have the same status as WEL’s
So not approved and not legal.
Biological limit values BLV’s
Contained in CLAW 2002
Unlike BGMV’s BLV’s are binding statutory limits.
Two sets in claw
Action levels
Suspension levels
Each trigger a set of action that must be taken.
What is the meaning of adequate control ?
The appropriate Wel is not exceeded
The principles of good practice are followed
Additional measure for Carcinogen, mutagens and asthmagens exposure must be controlled to lowest level reasonably practicable.
Principles of good practice
Design, takes, control, choose effective, PPE
Check and review, inform and train, not increase.
Design and operate activities and processes to minimise emission, spread and release of substances
Take into account all relevant routes of exposure inhalation, ingestion skin.
Control measures that are appropriate to health risk
Choose effective and reliable control options to minimise the escape and spread
Where adequate control cannot be achieved by other means provide in combination with other means suitable ppe
Check and review all elements of control and there effectiveness
Inform and train all employees on hazardous substances and control measures
Ensure the introduction of controls does mot increase the risk to H&S
What are the three types of Asbestos and what are the three categories or work ?
Crysotile white
Amosite Brown
Crocidolite Blue
Non licensed work
work is short duration, low fibre release is expected, asbestos in good condition and firmly bonded in a matrix. No notifiable to Authorities.
Notifiable licensed work
Short non continuous duration, high fibre release when disturbed, Asbestos in poor condition , poorly bonded in matrix. Authorities must be informed.
Licensed work Longer duration (more than one hr week) asbestos coatings, lagging.
What are the exposure levels and control measures for Asbestos
Use of RPE where the control limit of 0.1 fibres/cm3 over four Hours. Or peak exposure of 0.6 Fibres/cm3 over 10 minutes.
Risk assessment Removal plan Inform authorities RPE Health Surveillance Negative pressure Signage (asbestos areas and RPE areas) Duration, numbers and Frequency Air monitoring
List the component parts of LEV systems?
The Hood
The receptor
Contaminant directed naturally into the hood by thermal draughts, directional movement (solids) or local generation
The captor
Contaminants captured by airflow into the hood.
Ducting
Straight as possible with gentle bends
Filter or purifying system
Cyclones, scrubbers, washers, bag filters and electrostatic systems
Ventilation fans and motors
Axiel or centrifugal
Exhaust outlet.
What do u use to measure static pressures in LEV
Manometer
Displacement of a column of liquid in a u tube
Diaphragm
Gives reading on gauge as result of direct pressure on diaphragm
How often should LEV systems receive an inspection and what inspections should be done ?
Coshh 14 months
Lead 14 months
Asbestos 6 momths
Stage 1 visual All external parts for damage and wear Internal Duct and hat seals Filter and filter materials Pressure gauges Water scrubber levels sump and pump Fan or motor for damage Monitors or alarms Excessive system vibration
Stage 2 measuring technical performance
Transport velocity anemometer or pitot static tube
Static pressure manometer diaphragm gauge
Face velocity anemometer (heated head, swing vane, rotating vane.
Stage 3 assessing control effectiveness
Dust lamp dust particles to be visualised
Smoke pellet visualise air movement
Statutory provisions for ppe
Supply suitable ppe where the risks can’t be controlled by other suitable means
Is appropriate fir the task Takes into account ergonomic factors Fits Does not increase risk Ce marked
Two or more must be compatible
Ensure PPE is cleaned and replaced
Suitability and compatibility
Suitable storage
Provide IITS
Enforce PPE
What is meant by the term ergonomics ?
Designing the workplace/ work methods or work equipment to suit the worker.
