Hazardous Chemical Substances | Risk Assessment

Assessing the Potential Risk to Workers Posed by Hazardous Chemical Substances is Crucial

Working with hazardous chemical substances can threaten an employee’s health. A regular risk assessment is the most effective way to ensure their safety. While the entire world population is now affected by atmospheric pollution due mainly to the products of combustion from fossil fuels, many people face a significantly greater risk of coming into contact with toxic substances whilst at work. Suspended particles, such as asbestos fibres, gaseous substances, like ammonia, chlorine and bromine, or heavy metals like mercury, lead and cadmium, are frequently present in many workplaces. In addition, the mining industry employs strong acids and deadly cyanide to extract and refine precious metals.

Where the presence of such substances is known and appropriate countermeasures introduced, such risks must be eliminated or, at least, minimised. However, to do so, it is necessary first to confirm the presence of any chemical hazards and assess the extent of the threat they might pose to workers and anyone visiting the workplace.

Hazardous Chemical Substances

Conducting a Risk Assessment for Hazardous Chemical Substances

In most cases, the offending substances are present in the surrounding air, where they may pose a health hazard if inhaled. However, repeated skin contact with materials like lead filings can prove equally hazardous over a sufficiently long period.

Employers can usually confirm the identity of any potentially harmful substances employed in the workplace. However, they generally lack the specialised knowledge and facilities required to accurately assess the level of risk to which their employees may be exposed. In practice, this is a task that only a trained occupational hygiene technician has the necessary skills, experience and equipment to conduct. Nevertheless, a preliminary discussion with management and staff is an essential starting point in the assessment process. While an experienced industrial hygiene specialist will be familiar with the common hazards in most industries, specific input from an employer can be invaluable. Assessment or evaluation is the second step in a process known as a workplace survey, which begins by confirming and identifying any potentially hazardous chemicals present. However, in practice, detecting the presence of a known toxic substance in the workplace does not necessarily mean it might threaten the safety of those who work there. Each potential hazard must be assessed individually to determine whether it may be necessary to introduce suitably effective countermeasures. There are two steps to this process as follows:

  • Sampling: The occupational hygiene technician will collect air samples from different areas around the workplace and may also collect surface swabs if indicated. Sampling will be repeated at intervals during a typical eight-hour shift. The collected material will then be analysed in a suitably equipped laboratory. Testing will confirm the identity of any hazardous chemical substances present and provide an accurate measurement of the concentration of each.
  • Evaluation: This step is the cornerstone of a risk assessment and is designed to determine the level of risk posed to workers’ health by those chemicals found to be present. Local authorities publish a list of acceptable occupational exposure levels. Only if these are exceeded will countermeasures be necessary.


Arranging a Risk Assessment for Hazardous Chemical Substances


Employers can contact IOH Solutions, an accredited inspection agent and South African industry leader, to get a quotation and ensure their workers’ health and safety.


Contact Us for Hazardous Chemical Substance Risk Assessments