COSHH Substance Register: What It Is, What to Include, and How Long to Keep It

What Is a COSHH Substance Register?

A COSHH substance register is a master list of every hazardous substance your business uses, stores, or produces — the starting point for your entire COSHH compliance programme. It does not have a single formal name in the regulations themselves, but it is the practical tool that makes the rest of the law work: you cannot assess the risks from substances you have not identified, and you cannot train workers on substances you have not documented.

The register typically lives in a spreadsheet or document, though for businesses managing large substance volumes or multiple sites, a dedicated system makes more sense. Whatever the format, the register and your COSHH assessments are the records an HSE inspector will ask to see.

The Legal Basis for a Substance Register

The Control of Substances Hazardous to Health Regulations 2002 (SI 2002/2677) do not use the phrase "substance register" — but they create the need for one.

Under Regulation 6, employers must carry out "a suitable and sufficient assessment of the risk created by any work which is liable to expose any employees to any substance hazardous to health." Employers with five or more employees must also record the significant findings. You cannot make that assessment for every substance without first knowing which substances are present.

Under Regulation 7, employers must prevent or adequately control exposure. The control measures appropriate for a substance depend on knowing its hazard profile — which requires a documented record of what you have and what its SDS says.

The HSE's own guidance is explicit: before you can assess the risk, you need to identify what hazardous substances are in use. That identification stage produces what practitioners call the substance register.

What Your COSHH Register Must Contain

There is no prescribed format, but your register needs enough information to drive the risk assessments and training that flow from it. At minimum, each entry should cover:

Substance identification:

Product name (as shown on the label and SDS)
Supplier name
SDS issue date (so you can track when an updated version arrives)
Hazard classification — GHS categories, H-phrases, signal word (Danger or Warning)
Physical hazard class (flammable, oxidising, corrosive, etc.)

Use and location:

Where the substance is used (workshop, kitchen, plant room, vehicle)
How it is used — task type, quantities, frequency
Who is exposed, by role

Control status:

Date of current COSHH assessment
Review date for that assessment
Any WEL (workplace exposure limit) that applies — cross-reference to EH40
Health surveillance required? (Yes/No — reason)
PPE specified in the assessment

Data sheet reference:

SDS date and section 2 hazard summary
SDS version number (some substances update annually)

Keeping the SDS separately indexed alongside the register avoids duplicating the detail while keeping the register readable.

Common Gaps That HSE Inspectors Flag

Cleaning products and lubricants. Every substance counts — including the bleach under the sink, the WD-40 in the maintenance cupboard, and the cutting fluid in the machine shop. These are among the most commonly omitted categories because they feel routine.

Products from contractors. If a contractor brings substances onto your site, they become your responsibility too. The CDM Regulations and COSHH both require you to understand the hazards introduced by people working in your workplace. Request SDSs for any substance a contractor uses on your premises.

Substances generated by work processes. Dust, fume, and vapour created during work — welding fume, wood dust, soldering flux fume, spray paint mist — are not supplied with an SDS but still require assessment. These typically have HSE-set workplace exposure limits in EH40, and they need entries in your register.

Outdated SDSs. An older SDS may not reflect the current GHS classification. Suppliers are required to provide updated SDSs when new hazard information becomes available — the update obligation is event-driven, not tied to a fixed calendar interval. A register without SDS dates means you cannot tell which entries are stale.

How Long Do You Have to Keep COSHH Records?

The retention periods in COSHH vary by record type:

COSHH risk assessments: No specific retention period in the regulations, but the HSE recommends keeping them "as long as they remain relevant." In practice, keep each version until it has been superseded by a new assessment, and retain superseded versions for a reasonable period — commonly several years — in case of a complaint or inspection arising from past exposure.
Exposure monitoring records (Regulation 10): Records that are representative of an identifiable employee's personal exposure must be kept for 40 years from the date of the last entry. Other monitoring records must be kept for 5 years.
Health surveillance records (Regulation 11): Must be kept for at least 40 years from the date of the last entry. The 40-year period reflects the latency of occupational diseases such as occupational asthma and occupational cancer — conditions that may not present until decades after exposure ended.

The 40-year rule is not theoretical. An employee who develops mesothelioma 30 years after an exposure event may bring a claim, and the records from that time are what determines whether adequate controls were in place.

Keeping the Register Accurate

A register that is accurate on the day it is created and then forgotten is worse than no register — it gives a false sense of compliance while the actual position drifts. Build update triggers into your processes:

Trigger a register review when:

Any new substance arrives on site (add it before first use, not after)
An existing product is replaced with a different product (even if the replacement is described as "equivalent")
An SDS is updated by the supplier
A work process changes in a way that alters how or where a substance is used
The workforce changes and new people are exposed to existing substances

Most businesses find an annual review catches the accumulation of gradual drift — new products added informally, discontinued products still listed, SDSs replaced by newer versions. The annual sweep, combined with the point-of-change triggers above, keeps the register reliable.

Substance Register vs COSHH Assessment: Not the Same Thing

The register and the assessment are related but different documents. The register identifies and describes all substances. The assessment, for each substance, evaluates the actual risk of harm in your specific workplace — who is exposed, how often, at what concentration, with what controls.

You need both. A register without assessments tells you what substances you have but not whether you are managing the risk. Assessments without a register produce gaps — substances you have assessed without realising that other substances doing similar tasks are not on the list.

The COSHH assessment template covers what each individual assessment should contain. The register is the table of contents; each assessment is a chapter.

Substance Register and Your Chemical Register

Some businesses use the terms interchangeably. The key distinction: a COSHH register focuses specifically on substances hazardous to health under the COSHH Regulations. A chemical register template may cover a broader scope — all chemicals on site, including those that are not COSHH-classified but are nevertheless subject to storage, handling, or disposal requirements.

For most SME employers, one well-maintained document that covers both purposes is more practical than two separate registers. If your business generates significant quantities of non-COSHH chemicals (flammable substances under DSEAR, for instance), a DSEAR register alongside your COSHH register is worth maintaining separately.

Using a Register to Structure Your Training

The register is the input for your training programme under Regulation 12. Employers must provide workers with "suitable and sufficient information, instruction and training" — which means every substance on the register that a worker handles needs to be covered in that worker's induction or refresher training.

A well-structured register makes the training task manageable: you can group substances by work area, identify which workers need training on which substance clusters, and track which training has been delivered. Our COSHH Training Checklist for New Starters sets out the individual training records you should maintain alongside the substance register.

Sources

This guide is based on the Control of Substances Hazardous to Health Regulations 2002 as currently in force. For specific advice on your workplace's substances, consult a qualified occupational hygienist or health and safety adviser. Not legal advice.