Acute and Chronic Effects : The effects of accidents due to chemicals are severe and immediate on the human body. These effects are called acute effects and can be traced without difficulty. Frequently, poor lab practice or an unsafe system of work will lead to gradual poisoning. At first, effects may go unnoticed; or the effects may be attributed to the wrong cause. It may be hard to trace the real cause of these chronic or long term effects. In some cases, final results could be much worse than the immediate results. For instance, consider the effects of ingested alcohol:

1.  Acute effect - drunkenness and vomiting

2.  Chronic effect - addiction, liver damage, etc.

Safe lab practice will also minimize chronic effects. An example of good practice is ventilating the lab in the morning; this will minimize immediate poisoning or asphyxia (acute effect) and longer term poisoning (chronic effect) due to inhalation hazards.