COSHH Essentials and how to choose chemical exposure controls
COSHH Essentials uses hazard information, quantity and dustiness or volatility to select controls. Check HSE direct advice, then assess the workplace.
COSHH Essentials is HSE's basic advice on controlling exposure to hazardous substances at work. Its control banding method combines hazard information, the amount used and dustiness or volatility, then points you to a control guidance sheet. Check the industry-specific direct advice sheets first. A selected sheet supports your workplace COSHH assessment. It does not replace it. (HSE overview, direct advice, INSST method explanation, HSE assessment guidance)
Start with HSE's direct advice sheets
Before generic banding, check the direct advice sheets listed by industry. HSE tells you to look there first for tasks or processes in your industry. Those sheets are separate from the generic control guidance sheets in the COSHH Essentials collection.
Start with the operation, not the chemical name alone. Match the task to a sheet, then look at how exposure happens on that site. HSE's assessment guidance asks who could be exposed, by which route, how often and for how long, what you are already doing, and what further action is needed. A direct advice sheet does not answer those questions for you. (HSE COSHH assessment)
That index also carries a notice about workplace exposure limit changes introduced on 17 January 2020. Use the latest EH40 limits. They supersede limits in other HSE publications. (HSE direct advice)
How generic control banding selects an approach
Three inputs feed the generic method. INSST's 2012 explanation of COSHH Essentials shows how they combine. Use it for the selection logic. Do not treat its historical tables as current HSE instructions.
Hazard banding from the label and SDS
Read the hazard statements on the current label and safety data sheet. They place the substance in a lettered hazard group, A to E. If the statements point to different groups, use the highest one. (INSST NTP 936)
The letter codes and the approach numbers are easy to mix up. Groups A to E are the hazard banding input. Approaches 1 to 4 are the control response. And a hazard group on its own does not pick the controls, because quantity and release potential still count.
Amount used in the operation
Identify the quantity used in that operation. NTP 936 groups it as small, medium or large. Take the category from the guidance you are applying. Do not guess a cut-off. (INSST NTP 936)
Dustiness or volatility
For a solid, judge how readily it forms dust when handled. For a liquid, judge volatility at the working temperature. A boiling point taken at room temperature is not enough when the process is heated. The tendency to enter the air is then low, medium or high. Cross the three categories to select the control approach, then open the control guidance sheet for that operation. (INSST NTP 936)
The four control approaches
INSST's FCAQ collection lists four approaches for the translated COSHH Essentials advice sheets. The English names below follow the Spanish labels on that page:
| Approach | Control guidance |
|---|---|
| 1 | General ventilation |
| 2 | Engineering control, normally local exhaust ventilation |
| 3 | Containment using closed systems |
| 4 | Special: expert advice and specifically designed measures |
HSE says control approach 4 means you need more specific and specialist advice than "COSHH essentials: easy steps to control chemicals" provides. That advice may come from a more detailed HSE guidance document, or from an expert such as a qualified occupational hygienist. (HSE generic guidance) Do not treat approach 4 as a cue to add personal protective equipment and stop. Do not turn "general ventilation" into an instruction to open a window.
Apply the relevant sheet to the actual operation, then check whether the controls deal with exposure in that workplace. Choosing an approach and checking the controls already in place are different jobs. (INSST method explanation, HSE assessment guidance)
Why COSHH Essentials does not complete your risk assessment
Control banding selects a control measure. It does not measure the exposure that is actually happening, and it does not prove that controls already in place work. Existing controls are not an input. (INSST NTP 936)
The generic model in that 2012 note looks at inhalation. A supplementary S category can flag harm to skin or the external mucous membranes, but it does not evaluate that risk. Fire, explosion and chemical-accident risks need their own assessment. INSST's FCAQ collection also has separate skin and eye sheets. (INSST NTP 936, FCAQ sheets)
Do not read the result as a workplace exposure limit, or as proof that another hazard banding or occupational exposure banding scheme would reach the same answer. This is UK HSE guidance. Do not treat it as Spanish or US law.
Unusual release conditions need a closer look. The 2012 note says the COSHH Essentials generic method excludes gases and liquids handled above their boiling point, and that aerosols should be considered one case at a time. Get task-specific guidance rather than assuming the generic result covers those conditions. (INSST NTP 936) Do not carry that limit across to every current industry-specific sheet.
HSE's assessment page asks you to consider who might be harmed, which exposure route matters, how often and for how long people work with the substance, which controls are already in place, and what further action is still needed. Health hazards are not limited to substances labelled hazardous. Review the assessment regularly. A selected sheet is not a finished assessment. (HSE COSHH assessment guidance)
Spanish COSHH Essentials sheets from INSST
INSST's FCAQ collection provides Spanish translations of advice sheets developed by HSE for COSHH Essentials. Check the sheet you need against current HSE guidance before you rely on it. (INSST FCAQ collection) RegAffairs AI's answer on COSHH Essentials and the Spanish INSST sheets links the sources for how these sheets relate.
Do not assume every Spanish translation matches the latest English sheet.