- Adverse Effects may be local or systemic.
- Local Effects occur at the site of exposure e.g. corrosives and often irritants.
- Systemic Effects occur at a target organ or at site remote from the point of contact following absorption and distribution around the body.
Some substances produce both effects e.g. lead tetraethyl damages the skin on contact and is the absorbed and transported to the central nervous system where it may cause further damage.
Adverse Effects may also be acute or chronic.
- Acute Effects are immediate such as the effect from inhaling chlorine.
- Chronic Effects are much slower, often cumulative following repeated exposures. Chronic effects can be the most difficult to avoid because damage may not become evident for many years.
Adverse Effects may also be reversible or irreversible.
- Reversible Effects: damage can be repaired by the body’s natural processes.
- Irreversible Effects: cannot be repaired e.g. dead nerve cells cannot be replaced.
Adverse Effects may be psychological as well as purely physical.