Occupational Safety and Health Regulations, 1996, for Western Australia require that the employer, main contractor or self-employed person will undertake a risk assessment for each hazard from a “toxic atmosphere”.  Toxic atmosphere is defined as one where the concentration of the atmospheric contaminant exceeds its exposure standard (8-hour time weighted average basis) and presents a risk to health.

Occupational Hygiene may be defined as the science of anticipation, recognition, evaluation and control of physical, chemical, biological and ergonomic hazards in the workplace. It involves assessment of chemicals, dusts, fibres, gases, vapours, fumes, mists, noise, vibration, heat, cold, ionising radiation, non-ionising radiation, illumination hazards and similar.  The Occupational Hygienist observes processes and activities that may lead to materials being inhaled, swallowed or coming in contact with the workers skin. The Occupational Hygienist will normally need to understand the production and maintenance processes, the deployment of workers, the impact of work practices on exposures, and the toxicity or human health effects attached to the chemical, physical and biological agents present in the workplace.

An exposure assessment is the process for judging the acceptability of workplace exposures to chemical, physical and biological agents. They assume the absence of personal protective equipment.

Employees may be exposed to a few agents or, in some cases, many agents in the workplace.  The magnitude of exposure to these environmental agents varies from minute-to-minute, hour-to-hour and day-to-day.  The ideal goal is to assess the exposures and occupational health risks for all employees on all workdays and for all environmental agents.  However, there are obvious resource and technological constraints that make this impracticable. A strategy for meeting this challenge is the systematic formation of Similar Exposure Groups (SEG). 

A SEG is made up of one or more individuals who perform similar work and are expected to have similar exposures over time.  The classification of employees into SEGs is based upon an examination of the activities they perform and a judgment about the expected similarity of exposure. The underlying value in this strategy is that once employees are segregated into SEGs then exposure for a single employee in the group should be representative of the exposures for all employees in the group. 

The experienced staff at Occuhealth can provide all areas of the Health Risk Assessment, including collection of data, analysis and final assessments in order to give clients clear exposure assessments of their workforce along with strategies to ensure physical, chemical, biological and ergonomic hazards are controlled.