COSHH Assessment Review: When and How to Update

The Legal Requirement for Reviews

Regulation 6(3) of the Control of Substances Hazardous to Health Regulations 2002 states that a COSHH assessment must be reviewed "regularly, and forthwith if there is reason to suspect that the assessment is no longer valid or there has been a significant change in the work to which the assessment relates."

That wording is deliberately broad. There is no fixed legal interval — the HSE does not mandate an annual review in the regulations themselves. But the HSE's Approved Code of Practice (ACOP L5, paragraph 65) recommends reviewing assessments at least once a year as a general rule. In practice, annual reviews have become the standard expectation during inspections.

The more important point is the second part: you must review immediately when something changes. Waiting for the annual date when a trigger event has already occurred is a compliance failure.

What Triggers a Review?

Beyond the annual cycle, these specific events should trigger an immediate review of the relevant COSHH assessments:

Change of Product or Supplier

If you switch to a different brand, formulation, or supplier for a substance you have already assessed, the new product may have different hazards, different concentrations, or different handling requirements. Even products that appear identical can have different compositions — check the new Safety Data Sheet and update your assessment accordingly.

Change in Work Process or Equipment

Moving from manual application to spray application changes the exposure route and intensity. Installing new ventilation changes your control measures. Relocating work from a well-ventilated workshop to a confined space changes the risk profile entirely. Any of these demand a fresh look at the assessment.

Change in Quantities Used

Scaling up production, taking on a larger contract, or simply buying in bulk can change the exposure level. Using 500ml of a solvent-based adhesive per week is a different risk from using 20 litres per day.

Reported Health Symptoms

If a worker reports skin irritation, breathing difficulties, headaches, or any other symptom that could be linked to substance exposure, your assessment's conclusion that "controls are adequate" is now in doubt. Review the assessment, investigate whether the controls are actually being followed, and consider whether they are sufficient.

Incident or Near-Miss

A spill, a container failure, a ventilation breakdown, or any near-miss involving a hazardous substance is a clear signal that something in your assessment may not reflect reality.

New Information About the Substance

Manufacturers update Safety Data Sheets when new hazard information becomes available. Regulatory changes can reclassify a substance (as happened with welding fume in 2019, when the HSE reclassified all welding fume as a carcinogen). If you become aware of new hazard data, your assessment must be updated to reflect it.

Change in Personnel

New starters, particularly those who are young workers, pregnant, or have pre-existing health conditions, may be more vulnerable to certain exposures. If your assessment identifies specific groups at risk, a change in who is doing the work can be a review trigger.

Changes in Legislation or Workplace Exposure Limits

When WELs are revised — as they periodically are in the HSE's EH40 publication — any assessment referencing the old limit needs updating. Similarly, new ACOP guidance or HSE sector alerts may change what constitutes "adequate" control.

What a Proper Review Actually Looks Like

This is where many businesses fall short. A proper COSHH assessment review is not just changing the date on the front page and signing it again. That approach — which the HSE sometimes calls a "tick and flick" review — is one of the most common COSHH mistakes and will not stand up to inspection.

A genuine review means working through the assessment and asking specific questions:

1. Is the Substance Information Still Current?

Is the SDS still the most recent version from the supplier?
Has the product been reformulated since the last assessment?
Are the hazard classifications (H-phrases, GHS pictograms) still correct?

If your SDS is more than 5 years old, request an updated version from the supplier regardless.

2. Does the Assessment Still Reflect How the Work Is Actually Done?

Walk the workplace. Watch the task being performed. Compare what you see with what the assessment describes.

Common gaps that appear over time:

The assessment says work is done in a "well-ventilated area" but the workspace has changed and ventilation is now poor
The assessment describes a process that has been modified — different tools, different application method, different frequency
The assessment refers to PPE that has been substituted with a different type or is no longer available

3. Are the Control Measures Still Adequate and Being Used?

Is the ventilation system maintained and working? (Check LEV test records — LEV must be tested at least every 14 months under COSHH Regulation 9)
Is PPE being worn correctly and consistently?
Are safe working procedures being followed as written, or have shortcuts crept in?
Has any equipment been replaced, moved, or fallen into disrepair?

4. Has Anything Changed with the Exposed Workers?

Are there new starters who have not been trained?
Has anyone reported symptoms?
Are health surveillance results showing any trends?
Has the number of exposed workers changed?

5. Is the Risk Rating Still Accurate?

Based on everything above, does the overall risk conclusion still hold? If controls have degraded or circumstances have changed, the risk may have increased since the last assessment.

How to Document a Review

Documentation is critical. An undocumented review might as well not have happened — you have no evidence to show an inspector.

At minimum, record:

Date of review
Name of the person who carried out the review
What was checked (the questions above, in whatever level of detail is appropriate)
Outcome: either "no changes required — assessment remains valid" or a description of what has changed and what action is needed
Next review date

If changes are needed, update the assessment itself and record the changes. Keep the previous version as well — a simple version history demonstrates that you are actively managing your assessments rather than treating them as static documents.

A review note can be brief. For an assessment where nothing has changed:

Reviewed 2 April 2026 by J. Smith. SDS confirmed current (v3, issued September 2024). Work process unchanged. Ventilation tested 15 January 2026 — adequate. PPE stocks checked — sufficient. No symptoms reported. No changes required. Next review: April 2027.

For an assessment where something has changed:

Reviewed 2 April 2026 by J. Smith. Supplier changed from Brand A to Brand B for general-purpose degreaser. New SDS obtained (v1, issued March 2026). Hazard classification unchanged (H315, H319, H336). Concentration of active ingredient slightly higher (15% vs 12%). Updated dilution instructions in control measures to reflect new product guidance. Staff briefed on 3 April 2026. No other changes. Next review: April 2027.

Building a Review Schedule That Works

For a business with a handful of substances, setting annual calendar reminders is sufficient. But as the number of assessments grows, keeping track of review dates across spreadsheets and diaries becomes unreliable.

Practical approaches:

Spreadsheet tracker: A single sheet listing every assessment, its last review date, and next review date. Sort by next review date and check it monthly.
Stagger your reviews: If you have 24 assessments, review 2 per month rather than trying to do all 24 in January. Spreading the workload makes it more likely to actually happen.
Assign ownership: Each assessment should have a named reviewer — the person responsible for knowing whether the work has changed and whether controls are being followed. This is usually a line manager or supervisor, not the health and safety officer working from a desk.
Link reviews to other routine checks: If you already do monthly workplace inspections, add a COSHH review check to the inspection form.

The Difference Between a Review and a Re-Assessment

A review checks whether the existing assessment is still valid. A re-assessment means starting from scratch — going through the full COSHH assessment process as if the substance were new.

You need a full re-assessment when:

The substance has changed fundamentally (new product with different hazards)
The work process has changed so significantly that the original assessment no longer applies
The original assessment was inadequate or incomplete

For most annual reviews where circumstances have not materially changed, a documented check is sufficient. You do not need to rewrite the entire assessment each year — but you do need to demonstrate that someone competent has confirmed it is still accurate.

What Happens If You Do Not Review?

An overdue COSHH assessment is a common finding in HSE inspections and a frequent basis for improvement notices. The inspector's logic is straightforward: if you have not reviewed the assessment, you cannot demonstrate that the controls are still adequate, which means you cannot demonstrate compliance with Regulation 6.

Beyond enforcement action, the practical risk is that your controls quietly degrade while your paperwork stays frozen in time. Ventilation filters clog. PPE stocks run out and are not replaced. A new product gets introduced without anyone checking the SDS. Workers develop habits that bypass the written procedures. A review is your mechanism for catching these drifts before they cause harm.

Staying on Top of Reviews

The biggest reason reviews slip is that there is no system prompting anyone to do them. Review dates buried in Word documents on a shared drive are invisible until someone goes looking — and nobody goes looking until an inspector asks.

COSHHmate is being built with automatic review reminders at its core. You will receive email notifications before each assessment's review date, with a direct link to the assessment so you can complete the review in minutes. Every review is timestamped and stored against the assessment, building a documented history automatically.

Join the waitlist to be first to know when COSHHmate launches.