Working for hygiene

Health hazards in the workplace abound, so occupational hygiene is something not to be taken lightly. NOSA provides some advice.

Occupational hygiene is more than simply washing your hands on a regular basis or having clean premises. Rather, it is a discipline entailing the anticipation, recognition, evaluation and control of health hazards in the workplace, with the objective to protect the health and well-being of those working there.

Health hazards in the working environment can emanate from many sources. These might include chemical agents, physical agents, biological agents, ergonomic factors and psychosocial factors. Excessive exposure to these types of factors can have a variety of impacts on the worker.

Two important laws govern occupational hygiene in the workplace. Firstly, the Mine Health and Safety Act (MHS Act), 29 of 1996, which is intended to ensure a healthy and safe environment in mines/quarries and works. The second piece of legislation is the Occupational Health and Safety Act (OHS Act), 85 of 1993, which is intended to ensure a healthy and safe environment in factories and offices.

Risk assessment and occupational hygiene monitoring are required by both these Acts. Regulations promulgated under the MHS Act cover airborne pollutants, thermal stress and noise, while specific regulations under the OHS Act cover exposure to asbestos, lead, hazardous chemical substances, hazardous biological agents and noise-induced hearing loss.

Thermal environment and lighting are covered under the Environmental Regulation for Workplaces. They prescribe certain Occupational Exposure Limits (OELs) that may not be exceeded.

Compliance with these legal obligations is done through Occupational Hygiene Compliance Testing, which is the minimum amount of monitoring required to demonstrate compliance with legal obligations. It forms part of a monitoring programme that includes taking measurements in accordance with procedures laid down in the applicable regulations, and then comparing those results with the relevant OELs.

Once excessive exposure is determined, control measures need to be formulated and implemented to eliminate or reduce the risk. This is normally accomplished by following a hierarchy of control, which combines a variety of engineering and operational/ procedural control measures.

Personal Protective Equipment (PPE) forms the first line of defence, where the correct choice of PPE devices, appropriate maintenance and comfort will ensure its effectiveness. Administrative controls – such as procedures, job rotation, shift work, biological monitoring programmes and training – are the second step in reducing exposure to risk. One step beyond this are engineering controls, which entails physically introducing, for example, local exhaust ventilation systems or changing layout design.

However, if one is to get really serious about occupational hygiene, the risks will need to be mitigated altogether. Segregation is the first basic step, locating hazardous processes in separate rooms or buildings.

Following that, elimination of the use of a hazardous agent, or the removal of a superfluous process, follows. This will need to be tied in with substitution; for example, replacing solvent with water-based chemicals. Finally there is isolation, which is the total or partial enclosure of processes or equipment.

Effective control strategies will combine several, if not all, of these measures, resulting in less exposure to hazardous elements, compliance with legislation and, ultimately, a happier workforce.