One of the fundamental requirements of the Control of Substances Hazardous to Health Regulations (COSHH) is the prevention or control of exposure to substances hazardous to health.
Where you have hazardous substances, you must have controls measures in place to reduce the risk of exposure. After all, these substances are called hazardous for a reason - they can harm peoples health and in some cases, cause serious and permanent damage.
(3) Where it is not reasonably practicable to prevent exposure to a substance hazardous to health, the employer shall comply with his duty of control[...] by applying protection measures appropriate to the activity and consistent with the risk assessment...
And, just like carrying out a COSHH assessment is a legal requirement, so is the need to control the hazards and risks you identify.
If you have read our post on the principles of prevention, you will know that not all control measures are created equally. But what protection measures are best to use for COSHH? And in what order of priority?
Here are 7 types of COSHH control measures, in order of priority, with details on how they reduce the risk from hazardous substances.
The COSHH regulations first require exposure to be prevented. This can be done by eliminating hazardous substances entirely, and therefore control exposure by getting rid of the risk in the first place.
This might involve changing a process completely to avoid the use of the substance.
(1) Every employer shall ensure that the exposure of his employees to substances hazardous to health is either prevented or, where this is not reasonably practicable, adequately controlled.
Of course, it's not always possible to eliminate a substance. Sometimes, hazardous substances do need to be used, so you can't entirely prevent the risk of exposure. Now we need to think about how the risk can be controlled.
Another way to prevent exposure to a hazardous substance is to substitute it, for a less hazardous alternative.
An example of this could be changing from oil-based to water-based paints. Or changing from a chemical based cleaning product to a more natural alternative.
You might also substitute or even change a product to a safer form. For example, use a paste rather than a spray. Another example would be to damp down a dust during drilling so that it doesn't become airborne.
With thousands of products available, a review of various suppliers can often result in finding lower hazard alternatives.
Can the process be changed to reduce exposure to hazardous substances? Reviewing the way you work might highlight COSHH problems.
For example, it might be standard practice for operatives to sweep up after they have finished working, and this could cause dust to become airborne again. Changing the process to damp down before sweeping or cleaning up, or to use damp rags to clean up, will help to prevent the particles becoming airborne again.
Engineering controls are the next option on our list. This would involve the design of systems and work equipment to control exposure, ideally at the source to prevent or greatly reduce peoples exposure to a safe level.
You can use engineering controls to enclose the process and prevent the hazardous substance from escaping outside the enclosure. You can also use engineering controls to extract emissions at or near the source.
These controls might include:
As the employer, you must make sure that the COSHH control measures keep working properly. You can also put in place certain rules to keep exposure minimised to a safe level.
These supervisory controls could include:
For example, you might say that only particular people are allowed within a COSHH enclosure, and they must have certain training and be wearing and using specific equipment.
Supervisory controls usually have to be enforced, because unlike engineering controls, they rely on being followed and obeyed.
When you think about control measures, personal protective equipment (PPE) is often one of the first things that might come to mind. But actually, it's one of the last items on this because, while an important control, PPE is a last resort control measure.
It can only control the risk to one person at a time, and PPE does not reduce the hazard, so a failure of the equipment will expose the wearer to the maximum health risk.
It's always best to combat the hazard at the source first to reduce the risk.
None the less, PPE is still an important control measure. To be effective it should fit the user, and be comfortable and suitable for the risks they are likely to be exposed to.
A combination of control measures may be used for maximum risk reduction.
You might use control equipment in addition to PPE. You might substitute a hazardous substance for a lower risk substance but still needs to have other controls in place, like dust suppression, enclosures and PPE.
Often the best way to implement COSHH control and get the risk adequately controlled is through combining control measures.
When you are using a mixture of control measures, it is important that they all work together. Remember to look at the process as a whole, and consider how each control impacts another.
For example, if you substitute a power for a paste to lower the risk of inhalation, then you may also need to change the users PPE, to give more protection to skin contact, rather than respiratory protection.