Occupational Hygiene

Question 1

What are the six elements of an occupational hygiene program? (Hint - Same as an OHS Program)

Answer 1

1) Management Involvement 2) Hazard ID and Risk Control 3) Rules and Procedures 4) Training 5) Communication 6) Accident/Incident Reporting and Investigation

Question 2

What is a principle of the code of ethics in Industrial Hygiene?

Answer 2

1) Use scientific principles to practice the profession and protect the health and well being of workers. 2) Counsel affected parties about possible exposures to hazards and what methods and controls are available for safe work. 3) Maintain confidentiality of personal and business information. 4) Avoid conflicts of interest. 5) Perform services only in areas of competence.

Question 3

1) What 1883 act put increasing pressure on employers to provide workers a safe workplace? 2) When did workers compensation first become available in Canada? (And where)

Answer 3

1) 1833 - The Factory Act 2) 1915 - In Ontario

Question 4

What are some job functions of an Occupational Hygienist?

Answer 4

1) Direct an occupational hygiene program 2) Workplace inspections 3) Study processes to obtain full details of potential exposures 4) Measure stressors or factors to determine exposure 5) Conduct training and education 6) Interpret workplace in terms of potential to cause ill health.

Question 5

What was Pliny the Elder’s contribution to Industrial Hygiene?

Answer 5

Noticed workers in dusty trades used masks and that slaves who worked with asbestos got sick.

Question 6

Who is considered the greatest contributor to the science of Industrial Hygiene? What was his observation and quote?

Answer 6

Paracelsus He described miners lung/asthma/dyspnea and attributed it to vapors. Quote - “All substances are poisons, the right dose differentiates a poison from a remedy.”

Question 7

What are the cornerstones of an effective Occupational Hygiene program?

Answer 7

Anticipation of hazards Recognition of hazards Evaluation Control

Question 8

What is the ACGIH and what are they most famous for?

Answer 8

The American Conference of Government Industrial Hygienists - They publish Threshold Limit Values, most famous for the TLV Booklet.

Question 9

What is AIHA and what do they do?

Answer 9

The American Industrial Hygiene Association. They promote study, evaluation, and control of environmental stresses. Provides training and develops educational resources. Founded in 1939.

Question 10

• What is OSHA?

Answer 10

The Occupational Safety and Health Administration. They are the US regulatory enforcers, and educate about hazards.

Question 11

What is NIOSH What is the CRBOH and what designation does it administer? What is the ABIH and what designations does it administer?

Answer 11

The National Institute of Occupational Safety and Health. Canadian Registered Board of Occupational Hygienists, ROH (Registered Occupationl Hygienist) and ROHT (Technologist) American Board of Industrial Hygienists. CIH - Certified, CAIH - Certified Associate

Question 12

What was Hippocrates Greatest Contribution to Industrial Hygiene?

Answer 12

Hippocrates identified lead poisoning in miners.

Question 13

Who was the “father of Industrial Medicine?” - What was his book called? - What question did he believe should be included in every patient case history?

Answer 13

• Bernardo Ramazzini - De Morbis Artificum Diatriba - The diseases of workmen (contained description of occupational diseases including silicosis) - What trade are you?

Question 14

______ is an OHS discipline concerned with exposure of workers to airborne contaminants, skin contaminants, and other harmful agents.

Answer 14

Occupational Hygiene

Question 15

What is the definition of Occupational Hygiene?

Answer 15

Science and Art devoted to the anticipation, recognition, evaluation, and control of those environmental stressors arising in or from workplace which may cause sickness, impaired health and well being, or significant discomfort among workers.

Question 16

Who passes Statutes?

What is the difference between statute law and common law?

Answer 16

The highest governing power in the jurisdiction. Federally it is passed in the house of commons.

Statue law is based on actions of a person w/respect to others compared to written obligations (Acts Regs Codes). Common law is based soley on past or current judicial decisions.

Question 17

How many legislative authorities are there in Canada?

What type of law does WCB fall into?

What health and safety code applies to Federally legislated workers?

Answer 17

14. 1 Federeal, 10 Provincial, 3 Territorial.

Administrative Law, taken care of provincially by administrators.

Canada Labour Code part II.

Question 18

What is Specification Based Legislation? Example.

What is Performance based legislation? Example

Answer 18

Regulations are quantitatively specific. More focus on REACHING the desired outcome. IE Hearing protection must be worn above 85 dBA.

Regulations are less quantitatively specific. More focus on the outcome than the process of getting there. IE Employer must monitor for airborne contaminants if workers may be exposed.

Question 19

What are examples of Occupational Hygiene hazards which have no threshold effect? Meaning a single dose may cause the damage?

What are other names for Compliance Levels? PEL, OEL, TLV.

Answer 19

Asbestos, Carcinogens, Viruses, Allergic Agents.

Permissible Exposure Limits, Occupational Exposure Limits, Threshold Limit Values.

Question 20

Are TLV’s safe limits?

For what hazards might you use:
mg/m³?
ppm?
f/cc?

Answer 20

No, They are defined as compliance limits.

mg/m<sup>3</sup> = Gases, vapours, dusts, mist, fumes
ppm = gases, vapours
f/cc = fibrous substances

Question 21

What formula converts mg/m³ to ppm?

What are basic TLV’s based on?

Answer 21

ppm x MW = mg/m³ x 24.45

8 hour days, 40 hour weeks, 40 year careers without risk of ill health.

Question 22

What is an 8 hour or TWA-TLV?

What is a 15 minute or STEL-TLV?

What is a Ceiling or C-TLV?

Answer 22

Time weighted average for 8 hours a day/40 hours per week without risk of ill health.

15 Minute period of exposure continuously for a short time to be exposed to without suffering injury.

Concentration to ever be exceeded at any time.

Question 23

In Alberta if a TWA-TLV is provided but no STEL-TLV or C-TLV, what assumptions are you legally allowed to make?

Chemical X has 8 Hour TLV of 10, STEL-TLV of 25, rule is 4 excursions per shift. Is the following exposure time compliant?

8: 00-12:00 - 5ppm, 12:00-1:30 - 6ppm, 1:30-1:45 20ppm
1: 45-2:30 - 6ppm, 2:30-2:45 - 20ppm, 2:45-4:00 - 6ppm

Answer 23

You can create a STEL-TLV of up to 3x the TWA-TLV for 30 minutes/24 hours, and a C-TLV of 5x the TWA-TLV.

(5ppmX4 hours)+(6ppmX1.5 hours)+(20ppmX0.25 hours)+(6ppmX0.75 hours)+(20ppmX0.25 hours)+(6ppmX1.25 hours) / 8 hours = 6.38 ppm, Exposure is in compliance and under the TWA TLV of 10, and doesn’t exceed the STEL 4 exposure limit.

Question 24

Ammonia 8 Hour TLV of 25ppm, STEL-TLV 35ppm.
4 15 minute excursions allowed.
8:00-9:00 5ppm, 9:00-9:12 - 26ppm, 9:12-11:12 - 20ppm
11:12-12:00 - 28ppm, 12:00-4:00 20ppm.

Does this exceed the TWA-TLV? Is it in compliance?

Answer 24

(5ppmX1 hour) + (26ppmX0.2 hour) + (20ppmX2 hour) + (28ppmX0.8 hour) + (20ppmX4 hour) = 19.1
- This is a compliant TWA-TLV itself, HOWEVER, a max of 15 consecutive minutes is allowed for a STEL TLV and this exceeds it (48 minutes) so is not compliant.

Question 25

What is a TLV table?

Who publishes TLV tables?

Answer 25

Tabular form listing chemical name, associate exposure standard.

Many are published in legislation by jurisdictions.
The ACGIH also publishes a large list of TLV tables.

Question 26

What is the “Action Level” rule?

How do you calculate exposure to mixtures?

Answer 26

If the exposure cannot be eliminated the exposure must be reduced to 50% or less the TWA-TLV.

Calculate total exposure of combined chemicals.
D = (C1/TLV1) + (C2/TLV2) …
Units for C and TLV must be the same.

Question 27

If you are exposed to 10 ppm Toluene (TLV 50) and 40 ppm Ethyl Benzen (TLV 100), find the Dose. Are you compliant?

Answer 27

D=(10ppm/50ppm Toluene) + (40ppm/100ppm Ethyl Benzene) = 0.6
0.6 = 60% of allowed, it is compliant but over the action level, so action should be taken.

Question 28

Find Dose
Worker exposed to 3mg/m³ (TLV 10mg/m³) sulphur dust and 0.5ppm H₂S (TLV 10ppm). Is it compliant? Does it require action?

Answer 28

D = (3/10) + (0.5/10) = 0.35 or 35% of dose.
This is compliant (<1) and does not require action (<0.5)

Question 29

What is Sunergism?

What is Potentiation?

Answer 29

Synergism is when the effect of combined exposure is greater than the sum of the idividual effects. IE 1+2=6
Example: Likelihood of cancer in smokers exposed to asbestos.

The effect of exposure to a substance at a safe level is greatly increased by exposure to a second otherwise normal/acceptable level. IE 1+0 = 3
Example: Chlorinated Solvents and Alcohol.

Question 30

How does a longer shift create exposure “double trouble”?

What is F_a?

Answer 30

Longer shifts create longer exposure and a shortened detoxification period.

F_a is the TLV adjustment factor for non-standard shifts. F_a is multiplied by the 8 hour TLV to calculate the new TLV for shift length.

Question 31

What is the formula for F_a?

So what is the F_a for a 10 hour day?

If Xylene has a TWA-TLV of 100ppm, what is it for a 10 hour shift using the above calculation?

Answer 31

F_a = (8/h)(24-h/16)
Where h is the length of the increased shift.

F_a = (8/10)(24-10/16) = 0.7

100ppm x 0.7 = 70ppm

Question 32

What is an example of using a biological index to test for intoxication by a chemical?

What benefit is collecting a sample of blood and performing a Biological Exposure Index?

Answer 32

A breathalyser.

It is a measure of the total exposure a person recieves by all routes of entry including: inhalation, ingestion, and skin absorption.

Question 33

1) What is the most common Occupational Disease?
2) Skin varies from 0.5mm at eyelids to 3mm thick at soles of feet, what are the three layers it is composed of?
3) What are some signs of exposure to the skin?
4) What are some common sources of skin damage?

Answer 33

1) Occupational Dermatitis
2) Epidermis, Dermis, Subcutaneous Layer
3) Hives, Blotching, Bruising, Blisters, Rashes, Erosions, Dry
4) Cleaning products, acids, alkali’s, solvents, oxiders, reducers, plants, animas.

Question 34

1) What are the main functions of the renal system?
2) What are the sub-systems of the Digestive system?
3) What are some exit routes of substances from the body?

Answer 34

1) Filter out waste, reabsorb and secrete water, create urine.

2) Mouth/Teeth/Salivary glands
Esophagus/Stomach
Liver
Small and Large Intestine

3) Urine from kidneys, Feces, Expired Air, Perspiration, Tears, Lactated Milk

Question 35

How does the Liver work to detoxify?

What is, and what is the cause of:
Cirrhosis
Steostasis
Necrosis
Cholestasis

Answer 35

It lowers substances molecular weight and increases water soluability

• Hardening of liver resulting in reduced function - Alcohol
• Accumulation of fatty material - Antimony, Chloroform, CCl₄
• Cell Death - Allyl Formate, Beryllium, Cadmium, Selenium
• Impaired Bile Production - Manganeses, Toluene diamene.

Question 36

What is the endocrine system?

What are some glands associated with the endocrine system?

What is a Teratogen, Give 1 example.

What are functions of the hepatic system?

Answer 36

Chemical messaging system in the body

Pituitary, Thalamus, Thyroid, Adrenal Glands, Gonads

A chemical whose exposures harm the developing fetus - X-rays, Dioxins, Ethanol, Lead

• Breakdown of fats, metabolism, Chemical biotransformations, storage/breakdown/excretion of wastes.

Question 37

The Musculoskeletal system provides the main structure of the body (the ______) and the main means of motion (The _________ system).

The cardiovascular system does what?

What are the three regions of the respiratory system?

Answer 37

• Skeleton, Muscular
• Transports gases ad other materials around the body in the blood.

- Nasopharyngeal region (nose and airway)
Tracheobroncial region (upper area of lungs)
Distal region (alveolar or terminal air sacs)

Question 38

• Give examples of chemical exposures which may interview with the 3 processes of respiration:
  1) External Respiration (0₂ between lung and blood)
  2) Internal (O₂ between blood and cells)
  3) Intracellular (Use of O₂ and release of CO₂ at cells).

What, in regard to Pulmonary Function testing does:
FEF, FEV, FVC, PEF mean?

Answer 38

1) Nitrogen
2) Carbon Monoxide
3) Hydrogen Cyanide

• Forced Expiratory Flow
  Forced Expiratory Volume
  Forced Vital Capacity
  Peak Expiratory flow

Question 39

1) What is the inhalable size fraction?
2) What is the respirable size fraction?
3) What are the two major sub-systems of the nervous system?

Answer 39

1) Particles small enough to become airborne and be drawn into the respiratory system.
2) The smallest particles, 1-10 micrometers, which reach the deep lung. At high concentrations they appear as a “smoke”.

3) Central Nervous System - Brain
Peripheral Nervous System