Hazardous substances

Sources of hazardous substances include

* Substances used directly in work activities (e.g. adhesives, paints, cleaning agents);
* Substances generated during work activities (e.g. fumes from soldering and welding);
* Naturally occurring substances (e.g. grain dust);
* Biological agents such as bacteria and other micro-organisms.

Potential consequences of exposure include:

* Skin irritation or dermatitis as a result of skin contact;
* Asthma as a result of developing allergy to substances used at work;
* Losing consciousness as a result of being overcome by toxic fumes;
* Cancer, which may appear long after the exposure to the chemical that caused it;
* Infection from bacteria and other micro-organisms (biological agents).

Exposure can cause immediate effects or create longer term health problems (e.g. people become sensitised or develop cancer and other illnesses)

Also, people can have allergic reactions where immune system over-reacts to a substance that is safe for most people (e.g. food stuff).

Reference