Quick answer
Assess a new chemical or changed use before trial or routine introduction, using the actual task and current supplier information. Compare safer alternatives and establish workable controls, competence and emergency arrangements. Purchasing approval or a supplier’s general safety assurance is not the workplace COSHH assessment.
Review before introduction, including trials
GB COSHH regulation 6 requires assessment and implementation of necessary steps before work liable to expose employees. A small trial can still create exposure and is not automatically exempt.
HSENI guidance explains the separate NI assessment and control requirements. Identify the competent person and required technical input early, rather than asking staff to assess an unfamiliar delivered product while a job waits.
Collect the relevant information
| Area | What to establish |
|---|---|
| Identity | Exact product, formulation and current label/SDS. |
| Use | Quantity, concentration, method, duration and frequency. |
| Exposure | Routes, affected people and non-routine work. |
| Controls | Prevention, equipment, instructions and suitable protection. |
| Compatibility | Storage, existing substances, equipment and waste implications. |
| Failure | Spill, exposure, equipment-failure and emergency arrangements. |
Information may need clarification from the supplier. Do not assume a similar trade name or weaker hazard symbol means the full task risk is lower.
Compare alternatives and unintended consequences
HSE substitution guidance recommends comparing alternatives, introducing the choice carefully and checking how it works. Consider a safer substance, form or process, not just a different brand.
For food premises, also assess cleaning/disinfection effectiveness and food-contact instructions. A reduced worker hazard must not be achieved by losing a necessary food-safety control, and stronger cleaning claims do not remove worker precautions.
Control a proposed trial
Illustrative example: a supplier offers a concentrated replacement used through existing dosing equipment. Check compatibility, connection, required method, exposure and effectiveness before trial. Do not retain the previous product’s setting automatically.
Define the trial scope, trained people, supervision and stop criteria, then evaluate the actual results before approving routine use. Obtain competent advice for specialist reactions, exposure measurement or engineering changes.
Approve and implement the complete change
Update the assessment, register, labels, storage, instructions and relevant emergency information. Brief staff and contractors and remove obsolete instructions or unauthorised leftover stock appropriately.
Verify the approved arrangement in actual use and retain the decision evidence. Use the existing cleaning COSHH example and cleaning schedule to connect worker protection and the actual task.
Next steps
- Assess the proposed use before trial or introduction.
- Collect complete task/product evidence and compare safer alternatives.
- Approve a controlled trial with necessary competence and stops.
- Update the whole system and verify routine effectiveness.
Read the official practical guidance — Use the current source alongside the procedures for your own business.