Coshh regulations explained: keeping your workforce safe from hazardous substances

In workplaces across the United Kingdom, countless employees encounter hazardous substances as part of their daily routines — from cleaning products and chemical solvents to biological agents and industrial dusts. Understanding the legal framework that governs these risks is not merely a matter of good practice; it is a statutory obligation. COSHH regulations exist precisely to ensure that both employers and employees are equipped to manage these dangers responsibly, protecting long-term occupational health and maintaining safe working environments.

What COSHH Regulations Cover and Why They Matter in the Workplace

The term COSHH stands for Control of Substances Hazardous to Health. First introduced in 1988 and becoming law on 1st October 1989, the framework was subsequently updated to produce the COSHH Regulations 2002, which remain the current legislative standard. These regulations were established by the Health and Safety Executive to protect workers from the wide array of harmful substances they may encounter across industries as varied as manufacturing, healthcare, construction, and agriculture. A common misconception is that COSHH applies solely to the chemical industry; in reality, its reach extends across virtually every sector where hazardous materials are present.

Understanding which substances fall under coshh controls

The scope of hazardous substances covered by COSHH is broad. It encompasses chemicals, fumes, dusts, vapours, mists, gases, nanomaterials, and biological agents — essentially any substance that poses a risk to health through exposure. There are, however, notable exclusions: asbestos, lead, and radioactive materials are governed by their own separate legislative frameworks and fall outside the remit of COSHH. Substances can enter the body via four main routes — inhalation, skin absorption, ingestion, and injection — each carrying its own set of risks and control requirements. Certain chemicals are flagged with specific designations, such as ‘Sk’ for significant skin absorption potential and ‘Sen’ for sensitisation risk, helping employers understand the precise nature of each hazard. Hazard symbols, now aligned with CLP regulations, provide visual warnings on product labels and safety data sheets, replacing the older CHIP symbols with a standardised international system.

The legal duties placed on employers under coshh

Under COSHH, employers carry clear and enforceable legal duties. They must prevent or adequately control employee exposure to hazardous substances, maintain all control measures in good working order, and provide appropriate employee training so that workers fully understand the risks associated with the substances they handle. Workplace exposure limits define the legal concentration thresholds for hazardous substances: long term exposure limits are averaged over an eight-hour working period, whilst short term exposure limits are averaged over fifteen minutes. Hazardous substances have established workplace exposure limits monitored under this framework. Employers with five or more employees are required to record their risk assessments in writing. Non-compliance is treated as a criminal offence, and the financial and legal consequences can be severe when workplace safety measures are inadequate.

How to Carry Out a COSHH Assessment and Protect Your Workers

A robust COSHH risk assessment is the cornerstone of effective chemical safety management. It is not a bureaucratic formality but a practical process that identifies real hazards, evaluates the likelihood and severity of harm, and determines the most effective means of protection.

Steps to Identifying and Evaluating Hazardous Substance Risks

Conducting a thorough assessment begins with gathering comprehensive information about every substance present on site. Safety data sheets are an essential starting point, providing detailed information on the chemical properties, associated hazards, and recommended handling procedures for each product. Employers must then evaluate which employees are exposed, how often, and through which routes. The assessment should also consider substance storage, the potential generation of waste, and any tasks that might heighten exposure risk. It is worth noting that chemical mixtures can produce combined effects — which may be additive, synergistic, antagonistic, or potentiating — meaning that individual substance assessments do not always capture the full picture when multiple chemicals are used together.

Control Measures and Safe Working Practices to Safeguard Your Workforce

Once risks have been identified and evaluated, employers must implement appropriate control measures, following a hierarchy that prioritises elimination or substitution of hazardous substances before resorting to engineering controls or personal protective equipment. PPE, whilst sometimes necessary, should be considered a last resort rather than a primary safeguard. Maintaining good standards of workplace health also requires attention to compliance over time: assessments must be reviewed regularly, particularly when working practices change or new substances are introduced. Risk management under COSHH is an ongoing responsibility, not a one-off exercise. Employers are also encouraged to engage directly with their workforce on health and safety matters, as employees themselves have a duty to use the control measures provided and to report any deficiencies they observe. Regular refresher training — recommended at least annually or whenever new hazards emerge — ensures that awareness remains current and that toxic substances are handled with the care they demand.