1. Health Hazards
Instructional Goal
The participant will be able to interpret health hazard information for reducing personal risk when handling chemicals.

2. What is a health hazard?

3. Toxicology is the study of chemical toxicity
based on epidemiological studies
based on animal studies

4. Factors Affecting Human Response To Chemical Exposure
Toxic substances
Route of exposure
Chemical dose
Individual sensitivity
Interaction with other chemicals

5. Forms of Toxic Substances
Solids
Dusts
Fumes
Liquids
Vapors
Mists

6. Health Hazards Asphyxiants Carcinogens Flammable Irritants Sensitizers
Mutagens
Teratogens
Target Organ Poisons
You need to understand that some chemicals may fall into more than one category.

7. Target Organ Poisons CNS Circulatory system
Blood and blood forming system (hematoxins)
Liver (hepatotoxins)
Kidneys (nephrotoxins)
Reproductive Organs
Lungs
Skin
Eyes

8. Routes of Entry
Inhalation

9. Routes of Entry
Eye/skin (dermal contact)

10. Routes of Entry
Ingestion

11. Routes of Entry
Injection

12. Acute Response Headaches Dizziness Nausea
Eye, skin or respiratory damage
Unconsciousness
Death

13. Chronic Response Frequently not reversible Liver, kidney, lung damage
Target organ poisons
Storage in fat (adipose) tissue

14. Dose - Response Relationship
Dose of chemical
How much / How long
Response of the biological system

15. Dose Response Curve
Dose
Response
LD50

16. (quantity vs time of exposure)
Remember!!
Toxic Dose
(quantity vs time of exposure)
The smaller the number
the more toxic the dose!

17. Toxicity is
Rate of the potential for harm from a substance
Low toxicity vs. high toxicity

18. Toxic Concentration 500 - 5,000 mg/kg Moderately Toxic
Less than mg/kg Dangerously Toxic
1- 50 mg/kg Highly Toxic
mg/kg Toxic
,000 mg/kg Moderately Toxic
g/kg Low Toxic

19. “All substances are poison .....
The right dose differentiates a poison and a remedy.”

20. Substance Interaction
Additive = 4
Synergistic = 10
Potentiation = 4
Antagonism = 3

21. Toxic dose is based upon normal distribution and average health.
Genetic variability is a major factor.

22. Less Sensitive
More Sensitive
Average Population

23. PEL/TLV,IDLH are Exposure Limits
airborne concentration of a material to which nearly all individuals may be repeatedly exposed without adverse health effects.
helps eliminate factor of genetic variability

24. Common Units for Exposure Limits
ppm or ppb
used with liquid, vapor, and gas
mg/m3 (milligrams/cubic meter air)
used with solid particulates suspended in air

25. Exposure Limits Permissible Exposure Limit (PEL)
Threshold Limit Value (TLV)
Recommended Exposure Limit (REL)
Time-weighted average (TWA)
Short-term Exposure Limit (STEL)
Ceiling (C)
Immediately Dangerous to Life or Health (IDLH)

26. Exposure Limits PELs - OSHA's enforceable standards
TLVs - intended for use in the practice of industrial hygiene (ACGIH)

27. Cautions and Limitations Don’t use PELs, REls, TLVs
as fine lines between safe and dangerous
for evaluation or control of community air pollution
for estimating the toxic potential of continuous exposure
as proof of an existing disease or physical condition

28. Exposure Limits
Time Weighted Average
8 hour day
40 hour week

29. TWA, STEL, C
Measured Amount
Exposure (ppm)
TWA 8
Time (hours)

30. TWA, STEL, C Time (hours) Exposure (ppm) TWA STEL 4 1 2 34 1 2 3
Maximum of 15 minutes

31. TWA, STEL, C
Time (hours)
Exposure (ppm)
TWA
STEL 4 1 2 3 C

32. IDLH Values
Concentrations of toxic substance from which escape is possible without irreversible harm should a worker's respiratory protective equipment fail.

33. Toxicology Protection from Toxins
Know the potential for toxicity of the materials with which you work.
Know the signs and symptoms of toxins effects.

34. Toxicology Protection from Toxins
Use engineering controls.
Use common sense around chemicals.
Select and use protective equipment based on MSDS and safety officer recommendations.
Wash exposed areas thoroughly before eating, drinking, or smoking.