The laboratory is a unique work environment. Most labs involve processes with materials that are potentially hazardous. Therefore, employees should know of potential work hazards and how to avoid them. This two-part program will give you a better understanding of laboratory chemicals and your health. It is important to distinguish between toxicity and hazard when discussing the health effects of chemical substances.
Toxicity is the inherent ability of a material to cause adverse health affects.
For example, mercury can cause memory loss, as well as gastrointestinal and neurological problems. Hence, mercury is a toxic substance. Hazard is the likelihood that adverse health effects will occur. Taking one's temperature with a mercury thermometer is not hazardous, because the chemical is well contained within the thermometer. However, mercury released from a broken thermometer can be a health hazard.