COSHH and Hazardous Substances Training: A Guide for Employers

Cleaning products, solvents, dust, fumes and countless other substances used in everyday work can cause real harm if they're not properly controlled — from skin irritation and respiratory disease to more serious long-term health effects. Hazardous substances training teaches staff how to identify these risks and work with hazardous materials safely.

COSHH and its Irish equivalent

"COSHH" — the Control of Substances Hazardous to Health Regulations 2002 — is the specific piece of legislation that applies in Great Britain (England, Scotland and Wales), enforced by the Health and Safety Executive (HSE). It's such a widely used term in the safety training industry that "COSHH training" is often used informally as shorthand for hazardous substances training generally, even outside Great Britain. In Ireland, the equivalent legal framework is the Safety, Health and Welfare at Work (Chemical Agents) Regulations 2001 (S.I. No. 619/2001), made under the Safety, Health and Welfare at Work Act 2005 and enforced by the Health and Safety Authority (HSA), supported by an HSA Code of Practice for the Chemical Agents Regulations. The practical requirements are similar in both jurisdictions — assess the risk, control exposure, and train staff — but employers should be clear on which specific regulation actually applies to them. Learnsignal's CPD and compliance courses cover both frameworks as part of a wider statutory training programme.

What the regulations require

• Identifying which substances used or produced in the workplace are hazardous — from obvious chemicals to less obvious hazards like dust, fumes from a process, or biological agents
• Assessing the risk of exposure to employees and anyone else who might be affected
• Eliminating the hazard where possible, or otherwise controlling exposure — ventilation, containment, or personal protective equipment as a last resort
• Training employees on the specific substances they work with, safe handling and storage, and what to do if something goes wrong

Reading a Safety Data Sheet

A core skill covered in hazardous substances training is reading a Safety Data Sheet (SDS) — the standardised document a supplier must provide for any hazardous chemical product, setting out its composition, hazards, safe handling and storage requirements, and first aid measures. Training typically covers the internationally standardised hazard pictograms (the red diamond symbols for corrosive, toxic and flammable substances, among others) so staff can recognise risk at a glance, even before reading the full SDS.

Who needs this training

Anyone who works with or near hazardous substances as part of their role needs training specific to what they actually handle — a cleaner using industrial-strength products, a hairdresser working with chemical treatments, a construction worker exposed to dust or solvents, and laboratory or healthcare staff handling chemical or biological agents all have genuinely different exposure profiles and need training tailored accordingly, not a single generic session.

Safe storage and labelling

Good hazardous substances training also covers how products are stored, not just how they're used. That means keeping incompatible substances apart (an acid and a bleach-based product stored side by side can react dangerously if they leak or mix), ensuring containers are always correctly labelled — never decanted into an unlabelled bottle — and storing hazardous materials in a way that limits access to only those who need it. Poor storage practice is one of the most common gaps found during workplace inspections, often because it's treated as a housekeeping issue rather than a training and compliance one.

Personal protective equipment as a last resort

The regulations are clear that personal protective equipment (PPE) — gloves, masks, eye protection — should be the last line of defence, not the first. Good training explains this hierarchy: eliminate the hazard if possible, substitute a less hazardous product, control exposure through ventilation or engineering measures, and only then rely on PPE to protect the individual. Relying on PPE alone, without addressing the underlying exposure, is a common but incomplete approach that inspectors and auditors are quick to flag.

Frequently Asked Questions

Is COSHH training a legal requirement in Ireland?
The COSHH Regulations themselves are British legislation and don't apply in Ireland — but the underlying obligation to assess and control chemical hazard exposure is a legal requirement here too, under the Safety, Health and Welfare at Work (Chemical Agents) Regulations 2001.

How often should hazardous substances training be refreshed?
There's no single fixed interval — it should be reviewed whenever substances, processes or roles change, with a refresher at least every few years as general good practice.

Does this training cover biological agents too, or only chemicals?
Chemical and biological agents are usually covered by separate, though related, regulations and training — if your workplace has exposure to both, make sure your training programme addresses each specifically rather than assuming one course covers everything.

Hazardous substances are just one category of workplace risk that needs dedicated training — for physical injury risk, see our guide to manual handling training, and for a specific high-risk material, our guide to asbestos awareness training.