When considering the hazards associated with any workplace, it is essential to understand the relationship between ‘hazard’, ‘exposure’ and ‘risk’. ‘Hazard’ is the potential for an agent or process to do harm. ‘Risk’ is the likelihood that an agent will produce injury or disease under specified conditions. Health effects can only occur if a worker is actually exposed to the hazard. The risk of injury or disease usually increases with the duration and frequency of exposure to the agent, and the intensity/concentration and toxicity of the agent. The evaluation of toxicity takes into account the actual concentration of an agent in the body. The processes outlined above may result in the release of particles, vapours and gases to the environment. These agents may be hazardous if they are present in concentrations above the exposure standards