Hazardous substances are those substances that can cause harm to health, and may include:
Learn more about welding fumes and metalworking fluids by visiting our dedicated FAQ page on Welding Fumes and Metalworking Fluids.
Hazardous substances have several routes of entry into the body, where they can cause harm. The most common routes of entry for health hazards include:
Contact with a hazardous substance can have a range of effects that are classified as one of the following:
The specific effects that a hazardous substance has will depend on its nature but, because these effects can take many years to develop, it is often difficult to establish a definitive link between a substance and an illness. This is why many dangerous materials, such as asbestos, were used extensively for as long as they were.
There are a number of ways to tell that a substance is hazardous. One such way is by looking at its packaging.
The EU’s Globally Harmonised System (GHS) and the UK’s Classification, Labelling and Packaging (CLP) Regulations both set out a series of pictograms that must be present on a substance’s packaging if it poses a hazard to health. These pictograms are as follows:
Alongside pictograms, any hazardous substance that is being supplied for use at work must come with a Safety Data Sheet (SDS). This sheet will outline the hazards associated with a specific substance, making it easier to assess and control the risks that the substance poses in a specific workplace.
COSHH, or the Control of Substances Hazardous to Health Regulations, are a set of regulations designed to protect people from coming into contact with hazardous substances and experiencing ill health as a result. They cover all substances that are hazardous to health except asbestos, lead and radioactive substances, which are all covered by their own legislation.
The COSHH Regulations impose duties on employers to protect employees and others who may be exposed to substances hazardous to their health, and require employers to control exposure to such substances. They also offer a framework that employers can use to build a management system to assess the health risks associated with hazardous substances, and implement effective control measures.
When hazardous substances are considered for, or are in, use at a place of work, the COSHH Regulations impose certain duties on employers to prevent or reduce workers exposure to hazardous substances. They must do so in several ways:
Employers must undertake a suitable and sufficient assessment of the health risks created by work which is liable to expose their employees to substances hazardous to health and of the steps that need to be taken by employers to meet the requirements of these regulations (regulation 6).
Employers must prevent, or where this is not reasonably practicable, adequately control the exposure of their employees to substances hazardous to health. If exposure cannot be prevented, Workspace Exposure Limits (WELs), which are specified by the HSE for certain substances, must not be exceeded.
When preventing inhalation specifically, control should be achieved by means other than personal protective equipment where possible. If personal or respiratory protective equipment is still required, then it must conform with HSE standards (regulation 7).
Employers and employees must make proper use of any control measures provided (regulation 8). Employers must also regularly maintain any installed control measures, keep suitable records (regulation 9) and review their systems of work.
Monitoring must be undertaken of any employee exposed to certain substances (listed in schedule 5 of the regulations) or in any other case where monitoring is required for the maintenance of adequate control or the protection of employees. Records of this monitoring must be kept for at least 5 years, or 40 years where employees can be identified (regulation 10).
Also, health surveillance must be provided to any employees who are exposed to certain other substances (listed in schedule 6), and records of this surveillance must be kept for at least 40 years after the last entry (regulation 11).
Emergency plans and procedures must be prepared to deal with accidents or incidents involving exposure to hazardous substances beyond normal day-to-day risks. These should include details of any warnings and communication systems used to alert people immediately after any incident occurs.
Employees who may be exposed to substances hazardous to their health must be given information, instruction and training sufficient for them to know the health risks created by the exposure and the precautions which should be taken (regulation 12).
One of the main duties that the COSHH Regulations places on employers is to complete a COSHH risk assessment. This is used to identify any relevant hazardous substances that an employee may come into contact with, and establish how to adequately control exposure to them.
Not all hazardous substances are covered by the COSHH Regulations.
A COSHH assessment is very similar to a risk assessment, but it applies specifically to hazardous substances. The HSE suggests that a five step process is used to complete a COSHH assessment, which is outlined below:
Step 1: Gather information about the substances, work and working practices.
Step 2: Evaluate the risks to health either individually or collectively.
Step 3: Decide what needs to be done to control the exposure to hazardous substances.
Step 4: Record the assessment.
Step 5: Review the assessment.
Workplace exposure limits (WELs) are set by the HSE in its ‘EH40 Occupational Exposure Limits’ publication. They dictate how much of a substance an employee can be exposed to before new or additional control measures are required.
If an employee is exposed to a greater concentration of a hazardous substance than the workplace exposure limit allows, additional control measures must be implemented to reduce their exposure. Failing to do so is dangerous for employees, and can have significant legal consequences.
A COSHH assessment may determine that employees must undergo health surveillance, which is a regular system of ongoing health checks.
Health surveillance is important for:
The objective of the COSHH Regulations is to prevent ill health caused by exposure to hazardous substances. In doing so, employers are expected to develop suitable and sufficient control measures that control said exposure.
To help with this, the HSE has produced the eight principles of good practice that outline how control measures should be determined and maintained:
The COSHH Regulations require:
‘The prevention or adequate control of exposure by measures other than personal protective equipment (PPE), so far as is reasonably practicable, taking into account the degree of exposure and current knowledge of the health risks and associated technical remedies’
An effective way of determining which control measures should be implemented is the hierarchy of control, which lists the forms of control measure from most to least effective:
Elimination is the safest and most effective method of control, and is usually achieved by changing the process completely (such as using a brush applied paint rather than a spray paint).
If a substance cannot be eliminated, the next best alternative is to substitute it with something safer. For example, using a water-based paint poses less of a risk to health than an oil-based one.
Engineering controls may involve the use of a wide range of equipment, such as on-gun solder fume collectors, dust hoods, fume cupboards, and spray booths. Regardless of how they operate, all engineering controls will be designed to:
Supervisory controls include systems of work, effective communication and training. Some examples of supervisory controls include:
Personal protective equipment (PPE) can only be used as a control measure as a last resort. This is because it does not eliminate the hazard, and relies on good user training, the availability of the correct equipment at all times, good supervision and strong enforcement.
Still have more questions? Consider visiting our FAQ and answers about COSHH.
At Commodious, we offer a COSHH Awareness course that provides learners with all the information they need on COSHH. Successfully completing this course will also provide learners with an IIRSM-approved COSHH Awareness certificate: