What is COSHH on a Farm? A Complete Guide for UK Farmers
COSHH explained in plain English — what it means, which substances require assessments, and a practical guide to the ten most common farm chemicals and hazardous substances. Includes a blank assessment template to print and use.
Published 20 May 2026 · 12 min read
What Does COSHH Mean?
COSHH stands for Control of Substances Hazardous to Health. The COSHH Regulations 2002 require employers — including farmers who employ anyone, including family members — to identify substances that could cause ill health, assess the risk from those substances, and put controls in place to prevent or adequately reduce exposure.
On a farm, this covers a much wider range of substances than most farmers initially think. It is not just about pesticides. Diesel, engine oil, cleaning chemicals, veterinary medicines, slurry gases, grain dust and fertilisers all fall under COSHH. Any substance that has the potential to cause harm to health — through skin contact, inhalation, ingestion, or injection — requires a COSHH assessment.
COSHH is a legal requirement for all farms that employ people
The COSHH Regulations 2002 apply to any employer — including farms. Self-employed farmers also have COSHH duties to themselves and anyone affected by their work. COSHH assessments must be written, kept on file and reviewed when substances or processes change. Failure to comply is a criminal offence. HSE can issue improvement notices, prohibition notices and prosecute — fines are unlimited.
How to Complete a COSHH Assessment — Eight Steps
Identify the substance
Make a list of every substance used on the farm that could cause harm. Start with products that have warning symbols on the label (GHS hazard pictograms — skull and crossbones, exclamation mark, flame, corrosion symbol). Include substances generated by work activities — slurry gas, grain dust, welding fume.
Get the Safety Data Sheet (SDS)
Every chemical product must have an SDS supplied by the manufacturer. Request it from your merchant, download it from the manufacturer website, or find it on HSE's Chemical Hazard database. The SDS contains everything you need for your COSHH assessment — hazards, routes of exposure, first aid, PPE, storage.
Decide who might be harmed and how
Consider everyone who might be exposed: farm workers, family members working on the farm, contractors, visitors, young workers (under 18 have additional protections). Identify the routes of exposure for each substance — skin contact, inhalation, ingestion, injection/needlestick.
Evaluate the risk
How likely is exposure and how serious would the harm be? Consider existing controls — if you already use gloves and work outdoors, the risk from diesel handling is lower than if someone handles it in an enclosed space without PPE.
Decide on controls
Eliminate the hazard if possible (use a less hazardous alternative). If not, use the hierarchy: enclose the process, provide local exhaust ventilation, use general ventilation, provide PPE. PPE is the last resort — not the first.
Record the assessment
Write it down — date, substance, hazards, who is at risk, controls in place, PPE required, emergency procedures, risk level, assessor name, review date. Keep on file and accessible.
Train staff
Every person who uses or may be exposed to the substance must know: what it is, why it is hazardous, how to use it safely, what PPE to wear and how to use it correctly, what to do in an emergency.
Review regularly
Review when the substance or process changes, after any incident or near miss, and as a matter of routine — annually is good practice.
COSHH Assessments for the 10 Most Common Farm Substances
Click each substance to see hazards, routes of exposure, PPE requirements, controls and emergency procedures. These are starting points — always refer to the actual Safety Data Sheet for each specific product you use.
Slurry gas kills on UK farms every year
Hydrogen sulphide (H₂S) is colourless and initially smells of rotten eggs — but at high concentrations it paralyses your sense of smell. You lose the warning. One or two breaths at 700ppm can cause immediate unconsciousness and death. Most victims are people who entered to rescue someone else — without breathing apparatus, they became the second casualty.
Before agitating slurry
- • Open ALL doors and vents in housing
- • Remove livestock where possible
- • Ventilate for at least 30 minutes
- • Brief everyone present on the hazard
During agitation
- • Never stand directly over the store
- • Multi-gas detector carried at all times
- • Two persons minimum — one as lookout
- • Stop immediately if any symptoms felt
If someone collapses
- • DO NOT ENTER without breathing apparatus
- • Call 999 immediately
- • Get everyone else out of the area
- • Await emergency services outside
Never do these
- • Never agitate in a closed building
- • Never enter a pit alone or without SCBA
- • Never assume the gas has cleared
- • Never rely on smell as a warning
Blank COSHH Assessment Template
Complete one of these for each hazardous substance on your farm. Get the Safety Data Sheet for each product first — all the information you need is in there.
Where to Get Safety Data Sheets
Your agricultural merchant or supplier
Request SDS for every product you buy. They are legally required to provide one. Keep a file of all SDS received.
Manufacturer website
All major agro-chemical, veterinary medicine and farm supply manufacturers publish SDS on their websites — search the product name + "SDS" or "safety data sheet".
HSE COSHH essentials
hse.gov.uk/coshh — includes a tool for finding control approaches for common substances and a searchable chemical hazard database.
AHDB and BASIS
AHDB publishes crop protection guidance. BASIS (British Agri-Supply Industry Standards) maintains a register of pesticide products with full SDS and label information.
Complete your farm compliance picture
COSHH sits alongside health and safety, environmental management and food safety as the four core compliance areas for UK farms.
Frequently Asked Questions
Related Articles & Tools
For guidance only. The substance information in this guide is a general starting point — always refer to the actual Safety Data Sheet for each specific product you use, as hazards, PPE requirements and controls vary significantly between products. This guide does not constitute professional health and safety advice. HSE contact: hse.gov.uk or 0300 003 1647.