COSHH assessment: assessing the task, not the substance

A COSHH assessment is the assessment UK employers must make of health risks from hazardous substances at work, under the Control of Substances Hazardous to Health Regulations. It covers far more than the obvious chemicals: dusts, fumes, vapours, mists, gases, biological agents and substances generated by a process — welding fume, wood dust, flour, silica from cutting — count too, and the process-generated ones are where the serious long-term harm usually is.

The commonest failure is filing the supplier’s safety data sheet and calling it done. The sheet describes the substance; the assessment describes the task. Two people using the same solvent, one wiping a small part in a ventilated bay and one spraying a large surface in a confined space, are in completely different situations, and only the second half of that sentence is your responsibility to write.

What a COSHH assessment covers

• The substance and its hazards, taken from the safety data sheet and from what the process actually generates.
• The task: what is done with it, how much, how often, for how long, and by whom.
• Who is exposed, including people nearby who are not doing the work — cleaners, visitors, contractors.
• The route of exposure: inhalation, skin contact, ingestion, injection. Skin exposure is routinely underestimated.
• Existing controls, and an honest judgement of whether they are adequate for this task rather than in principle.
• Additional controls in the order of the hierarchy: eliminate, substitute, engineering control, then safe systems of work, with personal protective equipment last rather than first.
• Health surveillance where the exposure and the substance make it necessary.
• Emergency arrangements: spillage, exposure, first aid.
• The review trigger and date.

PPE last, not first

Reaching for gloves and a mask is the fastest way to close an assessment and the least effective control there is: it depends on correct selection, correct fitting, correct use every single time, and it fails silently. Elimination and substitution — a different product, a different method, a lower concentration — remove the problem; local exhaust ventilation removes the exposure at source. Where respiratory protection is genuinely necessary, face-fit testing and a maintenance regime are part of the control, not optional extras, and an assessment that specifies a mask without either has not finished the job.

Assess the task, not the cupboard. A list of every substance on site with a hazard classification against each is an inventory, and it is the document most often produced instead of an assessment. The regulator is asking what your people do with them.

Spills, splashes and exposures that nearly happened are worth recording too. A near miss report captures the event while details are fresh, so the assessment can be updated before someone is actually harmed.

Assessments date as fast as the lists behind them. Chemical compliance software keeps the substance inventory, current sheet versions and restricted-list screening in one record, so a reclassification triggers a review instead of passing unnoticed.

Keeping it alive

Assessments are reviewed when the process, the substance, the quantities or the people change, and periodically otherwise — and they only work if the people doing the task have read them. Ettex Forms captures the assessment at the workplace with photographs of the actual set-up, Ettex Docs holds the written assessments with version history so the one in force at a given date is recoverable, and Ettex Records tracks the review dates, the health surveillance record and the face-fit tests alongside the safety data sheet management library that feeds it.

To be clear: this is not health and safety advice and not a substitute for competent assistance. Exposure limits, health surveillance triggers and what counts as adequate control are technical questions, and for anything involving carcinogens, sensitisers or process-generated dust and fume they are questions for an occupational hygienist.