Hazardous substances are present in almost every workplace. Cleaning chemicals in a hotel kitchen. Industrial solvents in a manufacturing plant. Flour dust in a bakery. Biological agents in a care home. The risk of exposure to substances that can harm health is widespread and often underestimated.
In the UK, the control of hazardous substances at work is governed by specific regulations that place clear duties on employers. Understanding those regulations, and the practical steps required to comply with them, is essential for anyone who works with or around hazardous substances.
This guide explains what COSHH is, what the law requires, how to carry out a COSHH assessment, and how to protect yourself and your colleagues.
What is COSHH?
COSHH stands for the Control of Substances Hazardous to Health. It refers to the legal framework created by the Control of Substances Hazardous to Health Regulations 2002 (as amended), which requires employers to control exposure to hazardous substances in the workplace and protect the health of employees and anyone else who might be affected.
COSHH is not limited to chemicals in laboratories or factories. It applies to any workplace where people might be exposed to substances that can cause harm. In hospitality, that means cleaning products, sanitisers, oven cleaners, drain unblockers, and pest control chemicals. In healthcare and social care, it covers biological agents, cleaning chemicals, pharmaceutical products, and latex allergens. In manufacturing, the concern is solvents, paints, adhesives, metalworking fluids, and welding fumes. Construction workplaces deal with cement dust, silica dust, asbestos, paints, and sealants. Even offices are covered, since toner, cleaning products, and adhesives all fall under COSHH.
If you work in hospitality, the COSHH Awareness for Hospitality course is specifically designed for the substances and scenarios you encounter daily.
What counts as a hazardous substance?
Under the COSHH Regulations, a hazardous substance is any substance that can cause harm to health. These fall into several categories.
Chemical substances
These are the most commonly understood hazardous substances. They include cleaning products (bleach, oven cleaner, floor cleaner, glass cleaner, sanitisers, descalers), industrial chemicals (solvents, acids, alkalis, paints, adhesives, oils), and substances generated by work processes like fumes from welding, soldering, or cooking, and dust from woodworking, cement mixing, or flour handling.
Chemical substances are classified using the Globally Harmonised System (GHS) of hazard symbols. These are the diamond-shaped pictograms on product labels, including symbols for corrosive, toxic, flammable, irritant, and environmentally hazardous substances.
Biological agents
These are micro-organisms that can cause infection, allergy, or toxic effects. They include bacteria such as legionella (in water systems), E. coli, and salmonella; viruses such as hepatitis, norovirus, and bloodborne viruses; fungi including moulds and yeasts that can cause respiratory sensitisation; and parasites that can be encountered in food handling, agriculture, or waste management.
Dusts
Workplace dust is a major health hazard that is often overlooked. Flour dust is a significant respiratory sensitiser in bakeries and food manufacturing. Wood dust is carcinogenic at high exposure levels. Silica dust from cutting, drilling, or grinding stone, concrete, or brick is another serious risk. Even general workplace dust (any fine particulate matter that can be inhaled) falls under COSHH.
Fumes and vapours
Welding fumes contain a range of toxic metals and gases. Cooking fumes generated by high-temperature frying and grilling are a recognised respiratory hazard. Solvent vapours come from paints, adhesives, and cleaning products. Vehicle exhaust fumes are relevant in warehouses, loading bays, and workshops.
Substances not covered by COSHH
Some hazardous substances are covered by their own specific regulations rather than COSHH. Asbestos is covered by the Control of Asbestos Regulations 2012. Lead is covered by the Control of Lead at Work Regulations 2002. Radioactive materials are covered by the Ionising Radiations Regulations 2017.
What the law requires
The COSHH Regulations 2002 place eight key duties on employers.
1. Assess the risks
Employers must carry out a COSHH assessment for every hazardous substance used or generated in the workplace. This follows the same principles covered in our Risk Assessments course and must identify what substances are present, who might be exposed, how exposure might occur, and what the potential health effects are.
2. Decide on precautions
Based on the assessment, the employer must decide what control measures are needed to prevent or adequately control exposure. The regulations establish a hierarchy of control (see below).
3. Prevent or adequately control exposure
The employer must implement the control measures identified in the assessment. Prevention is always preferred over control. If a hazardous substance can be eliminated or substituted with a less hazardous alternative, that should be the first consideration.
4. Ensure control measures are used and maintained
Providing control measures is not enough. The employer must ensure they are actually used by employees and properly maintained. This includes regular inspection and maintenance of ventilation systems, extraction equipment, and PPE.
5. Monitor exposure
Where the COSHH assessment identifies a significant risk of exposure, the employer may need to carry out workplace exposure monitoring. This means measuring the levels of hazardous substances in the air to ensure they remain below Workplace Exposure Limits (WELs).
6. Carry out health surveillance
For certain hazardous substances and certain types of exposure, employers must provide health surveillance for affected employees. This might include lung function tests for workers exposed to respiratory sensitisers, or skin checks for workers handling irritant chemicals.
7. Prepare plans and procedures for accidents and emergencies
Employers must have plans in place for dealing with accidents, incidents, and emergencies involving hazardous substances, including chemical spills, leaks, or accidental exposure.
8. Ensure employees are properly informed, trained, and supervised
All employees who work with or might be exposed to hazardous substances must receive adequate training and information. This includes understanding the hazards, knowing how to use control measures, and knowing what to do in an emergency. Our Health and Safety for Employees course provides a solid foundation in general workplace safety duties that complements COSHH-specific training.
The hierarchy of control
The COSHH Regulations establish a hierarchy of control measures, applied in order of priority.
1. Elimination
Can the hazardous substance be removed entirely? For example, using a water-based paint instead of a solvent-based one, or using a cleaning process that does not require chemicals.
2. Substitution
Can the hazardous substance be replaced with a less hazardous alternative? For example, swapping a corrosive cleaning product for a milder one that achieves the same result.
3. Engineering controls
Can the risk be controlled by changing the way the work is done? This includes local exhaust ventilation (LEV) to extract fumes, dust, or vapours at the source; enclosed systems that contain the substance so workers do not come into contact with it; and automated processes that reduce the need for manual handling of hazardous substances.
4. Administrative controls
Can the risk be managed through work practices and procedures? Options include reducing the time workers spend exposed to the substance, rotating tasks so no individual has prolonged exposure, maintaining good housekeeping to prevent dust accumulation or spillages, and ensuring all containers have clear signage and labelling.
5. Personal Protective Equipment (PPE)
PPE should always be the last line of defence. It is used when the risk cannot be adequately controlled by other means.
Relevant PPE includes chemical-resistant gloves appropriate for the substances being handled, safety goggles or face shields for splash risks, face masks or respirators for dust, fumes, or vapour exposure, protective clothing such as aprons, overalls, or coveralls to prevent skin contact, and chemical-resistant boots or shoe covers.
PPE must be suitable for the specific hazard, properly fitted, maintained in good condition, and used correctly. Employers must provide PPE free of charge and train employees in its use.
Workplace Exposure Limits (WELs)
Workplace Exposure Limits are the maximum concentrations of hazardous substances in workplace air that employees can be exposed to. They are published by the HSE in EH40/2005 Workplace Exposure Limits, which is updated periodically.
WELs are expressed in two ways. The long-term exposure limit (8-hour TWA) is the maximum average concentration over an 8-hour working day. The short-term exposure limit (15-minute STEL) is the maximum average concentration over any 15-minute period.
Employers must ensure that exposure does not exceed these limits. If monitoring shows that WELs are being approached or exceeded, additional control measures must be implemented.
WELs represent the legal maximum. They are not safe levels. The aim should always be to reduce exposure as far below the WEL as is reasonably practicable.
COSHH assessments in practice
A COSHH assessment should be carried out for every hazardous substance used or generated in the workplace. Here is a practical approach.
Step 1: Identify the substances
Walk through the workplace and identify all hazardous substances. Check store cupboards, cleaning stations, kitchens, workshops, and any other areas. Do not forget substances generated by work processes: dust, fumes, vapours.
Step 2: Gather information
For each substance, obtain the Safety Data Sheet (SDS) from the manufacturer or supplier. The SDS provides detailed information about the substance’s hazards, safe handling procedures, exposure limits, first aid measures, and PPE requirements. Under UK law (UK REACH Regulation), suppliers must provide an SDS for any hazardous substance.
Step 3: Assess the exposure
For each substance, assess who might be exposed, how the exposure might occur (inhalation, skin contact, ingestion, eye contact), and how often and for how long.
Step 4: Decide on control measures
Apply the hierarchy of control. Can you eliminate the substance? Substitute it? Implement engineering controls? Change work practices? If PPE is necessary, specify the type and standard required.
Step 5: Record the assessment
COSHH assessments must be recorded if you have five or more employees. Even for smaller businesses, keeping a written record is strongly recommended. The record should include the substance name, the hazards, who is exposed, existing control measures, additional measures needed, and the review date.
Step 6: Review regularly
COSHH assessments should be reviewed at least annually and whenever there is a significant change, such as a new substance being introduced, a change in the way a substance is used, or after an incident or case of ill health.
COSHH in hospitality
Hospitality workplaces use a wide range of hazardous substances, often without adequate awareness of the risks. Kitchen cleaning products like oven cleaners, degreasers, and drain unblockers are often highly corrosive or irritant. Sanitisers and disinfectants are essential for food safety but can cause skin irritation and respiratory problems with prolonged exposure. Pest control chemicals, whether used by contractors or in-house, can be toxic. Industrial detergents and stain removers used in hotel housekeeping present risks. Hotels with leisure facilities use chlorine and pH adjusters for swimming pools. And cooking fumes generated by high-temperature frying and grilling are a recognised respiratory hazard that many kitchens simply accept as normal.
The COSHH Awareness for Hospitality course addresses these specific substances and scenarios. For more in-depth coverage of the regulations and assessment process, the Control of Substances Hazardous to Health (COSHH) course covers the full regulatory framework.
How to get certified
Getting your COSHH Awareness certificate through Chefs Bay Academy takes four steps. Start by purchasing a licence for £29, which gives you access to the COSHH courses and 130+ other courses in the library. Work through the course modules at your own pace on any device. Pass the end-of-course assessment to confirm your understanding. Then download your CPD accredited certificate immediately.
Your licence includes both the COSHH Awareness for Hospitality course (focused on hospitality-specific substances and scenarios) and the broader Control of Substances Hazardous to Health (COSHH) course (covering the full regulatory framework). Choose the one that best fits your role, or complete both.
For a broader view of workplace safety compliance, explore the full range of health and safety courses, covering fire safety, manual handling, first aid, and more. All are included in the same £29 licence.
Frequently asked questions
Is COSHH training a legal requirement?
Yes. The COSHH Regulations 2002 (Regulation 12) require employers to provide adequate information, instruction, and training for employees who work with or might be exposed to hazardous substances. This includes training on the hazards of the substances they work with, the control measures in place, how to use PPE correctly, and what to do in an emergency. There is no legal requirement to hold a specific certificate, but having one demonstrates compliance and due diligence.
How often should COSHH training be refreshed?
There is no legally mandated renewal period. The COSHH Regulations require training to be “suitable and sufficient” and updated when circumstances change. Best practice is to refresh COSHH training at least every three years, or sooner if new substances are introduced, work processes change, or after an incident. Many employers include COSHH awareness as part of annual refresher training.
What is a Safety Data Sheet (SDS)?
A Safety Data Sheet is a standardised document provided by the manufacturer or supplier of a hazardous substance. It contains 16 sections covering the substance’s identity, hazards, composition, first aid measures, firefighting measures, handling and storage, exposure controls, physical and chemical properties, toxicological information, and disposal considerations. Under UK REACH, suppliers must provide an SDS for any substance classified as hazardous. Employers must make SDSs available to employees who work with the substance.
Does COSHH apply to cleaning products?
Yes. Many common cleaning products are classified as hazardous substances under COSHH. Bleach, oven cleaners, degreasers, drain unblockers, and industrial sanitisers can cause skin irritation, chemical burns, respiratory problems, and eye damage. Employers must carry out COSHH assessments for all cleaning products used in the workplace and ensure staff are trained in their safe use.
Who is responsible for COSHH compliance?
The employer is responsible for compliance with the COSHH Regulations. This includes carrying out assessments, implementing control measures, providing PPE, monitoring exposure, providing training, and keeping records. Employees also have duties: they must use control measures and PPE as instructed, follow safe working procedures, and report any concerns about hazardous substances.
Related guides
If you found this guide helpful, you might also want to read:
- Fire Safety Training Requirements in the UK
- Manual Handling Training: What UK Workers Need to Know
- Infection Control Training: Essential Knowledge for Care Workers
All these courses are included in your Chefs Bay Academy licence — £29 for instant access to 130+ courses.