A hazardous substance is any material that can harm our bodies, either at the time of exposure or
later. These substances may be solids, liquids, gases, or dusts. The toxicity of a substance is the
ability of the substance to cause damage to living tissue, illness, or even death. The degree of toxicity
depends on several factors:
- Chemical makeup. Some chemicals are more toxic than others because
of their chemical structure.
- Amount. All chemicals are toxic. It is a matter of how much to
which you are exposed. For example, some chemicals, such as strychnine, that are extremely toxic
may have beneficial therapeutic
value when used in very small amounts in prescription drugs. The amount a person is exposed to
- Type of contact. There are three primary routes of entry for hazardous
materials. These are inhalation (entry through the lungs), absorption (entry through the skin or
eye), and ingestion (entry
through the mouth). Each of these routes can cause different effects.
- Length of contact. For some substances, a short contact may cause
no ill effect, while a long term exposure may be harmful.
- Personal susceptibility. Some of us are more sensitive to hazardous
materials than others. Some things that can cause any of us to be more sensitive are diet, smoking,
allergies, and pregnancy.
index | next page