What is a COSHH assessment, and how do you do one?

What it is, and what it is not

Regulation 6 of COSHH requires a suitable and sufficient assessment of the risk created by work liable to expose people to substances hazardous to health, and of the steps needed to meet the rest of the regulations. That phrase is doing the work: suitable and sufficient is a standard, not a form.

Which is why a printed safety data sheet is not an assessment. The sheet describes the substance in general; the assessment is about this job — how much, how often, in what space, with what ventilation, and who is standing nearby. Two firms using the same product can honestly reach different answers.

It is also not a document you write once. It is a decision you record, and it stops being valid when the work changes.

The seven steps

1. List what the work actually involves

   Both halves: what arrives in a tin, and what the work generates — dust, fume, mist, vapour. The second half is where assessments go wrong, because nothing arrives labelled for it and nobody thinks to write it down.

2. Find out what each one does to people

   The label and the safety data sheet for a supplied product; the published lists for a substance. Look it up to see its hazard classifications and whether it has a workplace exposure limit.

3. Work out who is exposed, and how

   Not only the person holding the tool. Breathing it, on the skin, in the eyes, swallowed off unwashed hands — and the labourer working downwind who never touched the product.

4. Judge how bad the exposure is

   How much, how long, how often, and in what space. The same task outdoors and in an unventilated basement are different assessments, and the exposure limit is the yardstick where there is one.

5. Decide the controls, in the right order

   Prevent first: do without it, swap it for something safer, change the method. Then engineering control — on-tool extraction, water suppression, ventilation. Administrative measures next. PPE is last, because it protects one person and only while it is worn correctly.

6. Write down the significant findings

   What the substances are, who is at risk, what the controls are, and who does what. Five or more employees makes the record a duty; below that it is still the only way anybody else can follow the decision. There is no official form — see what belongs in each part.

7. Tell the people doing the work

   An assessment in a folder that the gang has never seen has controlled nothing. Regulation 12 requires the information, instruction and training — and requires you to be able to show it happened.

A worked example: cutting blocks on site

Nothing in this example arrives with a label, which is exactly why it is the one worth working through. A bricklayer is cutting dense concrete blocks with a petrol disc cutter, outdoors, for about two hours a day across a week.

What a good assessment contains

There is no prescribed form. An assessor, a client or an inspector reading yours is looking for whether the thinking happened, and these are the things whose absence gives it away:

The job, not the product

Named work, named place, real quantities and durations. "General construction" is not an assessment.

The process exposures

The dusts and fumes the work makes, listed alongside the supplied products.

Everyone in the exposure

Including the people nearby who are not doing the task.

Controls in the right order

Evidence that prevention was considered before PPE, rather than a mask for every line.

Who does what

Named responsibilities — who checks the extraction, who face-fit tests, who reviews it.

A date and a version

So the next person knows whether they are reading the current one.

When it has to be reviewed

Regulation 6 requires the assessment to be reviewed regularly, and immediately if there is reason to suspect it is no longer valid, or if there has been a significant change in the work.

In practice: a different product, the same job moved indoors, a longer shift, a new person, a control that turned out not to work, or anything the monitoring or health surveillance turns up. An annual review is a sensible habit; it is not what the regulations ask for, and it will not save an assessment that stopped describing the work in March.

Questions people ask

What should a COSHH risk assessment include?

The substances the work involves — supplied and generated — what they do to people, who is exposed and by what route, how bad the exposure is, the controls in order of prevention before protection, who is responsible for what, and a date. Where five or more people are employed, the significant findings must be written down.

What is the first step in a COSHH assessment?

Listing what the work actually involves: both the products that arrive in a tin and the dust, fume, mist or vapour the work itself generates. The second half is the one most often missed.

Is a safety data sheet a COSHH assessment?

No. A safety data sheet describes a substance in general. An assessment is about your job — the quantity, duration, space and people involved — and reaches a conclusion about control that the sheet cannot.

How often should a COSHH assessment be reviewed?

Regularly, and immediately if there is reason to suspect it is no longer valid or the work has changed significantly. A different product, a move indoors or a longer shift are all triggers.

Who can carry out a COSHH assessment?

The regulations do not require a particular qualification. They require the assessment to be suitable and sufficient, which means whoever does it needs to understand the work, the substances and the controls — often the person running the job, supported by the safety data sheets and the published limits.