a. Breathing/inhalation takes a chemical from the nose or mouth, down the
windpipe, and into the lungs. Some chemicals get trapped in the lungs. Others leave
when you breathe out. But many pass from the lungs into the bloodstream.
b. Skin/eye contact can cause anything from reddening or itching to severe
rashes, burns, loss of eyesight, or even death.
Skin absorption hazards pass through the skin on contact and enter the
bloodstream. Once in the bloodstream, chemicals can spread throughout the body and
cause injury or disease far away from the original site of contact. Chemicals can also
be absorbed through the mucous membranes of the eye.
d. Swallowing/ingestion takes a chemical from the mouth, down the
esophagus, and into the stomach. From the stomach, many chemicals enter the
intestines where they can be absorbed into the bloodstream and spread throughout the
body. Damage can be done at any point along the way.
DEGREE OF HAZARD
The degree of hazard associated with exposure to health hazards depends on
Toxicity of the Chemical. See Table 4-1.
EFFECTS OF EXPOSURE
Minor symptoms that go away when exposure stops.
Require medical attention, may be permanent.
Can cause death or severely disabling conditions.
Table 4-1. Toxicity and its effects.
b. Exposure Route. Some chemicals are more toxic by one exposure route
than by another. For example, onion juice vapor irritates the eyes, but skin contact with
onion juice produces little or no effect.
Dosage. Dosage depends on:
(1) How much you were exposed to each time.
(2) How long each exposure lasts.
(3) How often you are exposed.