How often should COSHH assessments be reviewed?
Reviewed September 2026 · Written by Complys and checked against HSE and legislation.gov.uk guidance (sources below).
It's one of the most-asked COSHH questions, and the answer surprises people: there is no fixed legal interval. COSHH requires you to review regularly, and immediately when things change. Here's what the law actually says.
What the law says
COSHH regulation 6(3) requires the assessment to be reviewed regularly, and forthwith — straight away — if there's reason to suspect it's no longer valid, if there's been a significant change in the work, or if monitoring shows a review is needed. Any changes then have to be made.
The "every 12 months" myth
You'll often hear that COSHH assessments must be redone every year. That's not in the law. An annual review is sensible good practice and a reasonable default, but it isn't a legal requirement — and it doesn't override the duty to review immediately when something changes.
The triggers that mean 'review now'
Regardless of when you last reviewed, review straight away if any of these happen:
- A new substance, product or supplier
- A change to the process, method or quantities used
- New information about a substance's hazards, or a revised exposure limit
- Monitoring or health surveillance results suggesting controls aren't working enough
- An incident, near miss, spill or case of ill health
A sensible approach
Set a regular review cycle (many businesses use annually) as a backstop, but treat the triggers above as the real driver. The point isn't the calendar — it's that the assessment still reflects the work and the controls still protect people.
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Complys generates a COSHH assessment tailored to your actual substances and tasks — hazards, control measures, PPE, exposure limits and emergency actions — not a generic template you have to rewrite.
Sources
- COSHH 2002, reg 6 (assessment of health risks)
- Control of Substances Hazardous to Health Regulations 2002 (SI 2002/2677)
- HSE — COSHH assessments
This guide is general information, not legal advice. COSHH and chemical-classification rules change over time — always check the current HSE and legislation.gov.uk guidance for your work.
How often should COSHH assessments be reviewed? — FAQs
How often must a COSHH assessment be reviewed by law?
COSHH sets no fixed interval. Regulation 6(3) requires review 'regularly' and immediately if the assessment is no longer valid, the work has changed significantly, or monitoring shows it's needed.
Do COSHH assessments have to be redone every year?
No — that's a common myth. Annual review is good practice, but the legal duty is to review regularly and straight away when something changes.
What triggers a COSHH review?
A new or changed substance or process, changed quantities, new hazard information or exposure limits, monitoring or health-surveillance results, or an incident.