1. HEALTH EFFECTS
Opening Slide

2. OBJECTIVES When finished with this section, participants will be able to:
List the four Routes of Entry for chemicals into the body
Define the terms: Acute; Chronic; Target Organ; PEL; IDLH; and Dose Response
State Objectives

3. Routes of Entry How chemicals get into the body
Inhalation – INH
Ingestion – ING
Contact – CON
Absorption – ABS
Injection - INJ
Discuss the various routes of entry. State that Inhalation is the most common route of entry for chemicals into the body.
The abbreviations after the terms are what the participants will find on MSDSs and in the NIOSH Pocket Guide.
Point out that INJ (injection) is seldom listed. This occurs when there is a break in the skin, such as a puncture (stepping on a nail or a splinter) or scratch or cut (from wire or a tool). It can also occur from compressed air or hydraulics.

4. Acute vs. Chronic ACUTE Large dose over a short time
Effects usually within 72 hours
Effects may be temporary, permanent, or fatal
CHRONIC
Small dose over a long period of time
Effects may not appear for years
Effects are permanent and possibly fatal
Discuss the differences between Acute and Chronic. Stress that even though a worker may feel fine after an exposure, many effects of chemicals do not show up for weeks or years. In the case of Asbestos, it may be 10 to 40 years until the effects are known.

5. Target Organs
Chemicals can affect organs distant from the point of contact
Organs usually affected are the filters or the nervous system
Effects can either be acute or chronic
Even though an organ is not exposed to a chemical, it can still be affected. The most commonly affected organs are the liver and kidneys (The body’s filters) and the Central Nervous System.
The CNS includes the brain, spinal cord, and body functions that are not conscious acts (Breathing, Heartbeat, Digestion, Ability to Learn, etc.),

6. Exposure Limits PEL Averaged over 8 hours
Most individuals will not show adverse health effects below this level
IDLH
Will cause death, lasting health effects, or limit the ability to self rescue
All carcinogens are IDLH
Exposure limits are usually averaged over an eight hour workday. These are only averages. Stress that there is no way to predict how much of a certain chemical it will take to affect someone, as everyone is different.
PELs are legally enforceable exposure limits. They are set by law.
Other exposure limits are Threshold Limit Values (TLV) set by ACGIH and Recommended Exposure Limits (RELs) set by NIOSH.
DOE uses TLVs as their legal limit.
RELs are only recommendations and are not enforceable by law.

7. Dose Response The greater the dose, the greater the response
Everyone reacts differently
LD/ LC/50
An example of Dose Response would be a reaction to a bee sting. Not everyone reacts the same. Some people have a small red lump with itching. For other individuals, a bee sting is fatal.
LD/50 is Lethal Dose. This is the amount of a chemical (ING or INJ) that it took in laboratory studies to kill ½ of the test animals.
LC/50 is the concentration in the air that it took to kill ½ of the test animals.
While this is a good measure of the toxicity of a chemical, there are no reports of the condition of the remaining test animals.

8. OBJECTIVES When finished with this section, participants will be able to:
List the four Routes of Entry for chemicals into the body
Define the terms: Acute; Chronic; Target Organ; PEL; IDLH; and Dose Response
Restate objectives. Take any questions