Methodology & Editorial Policy
How coshhassessments.co.uk sources, verifies, and updates substance data. Written for HSE inspectors, insurers, buyers, and anyone auditing the origin of the content in a generated COSHH assessment.
1. Data sources
Each substance entry in our library is built from these primary sources, in this order of preference:
- HSE EH40/2005 Workplace Exposure Limits. The legally-binding UK list of Workplace Exposure Limits (WELs) for hazardous substances. TWA (8-hour time-weighted average) and STEL (15-minute short-term exposure limit) values in our library come directly from EH40 Table 1. See the current HSE EH40/2005 PDF.
- Manufacturer Safety Data Sheets (SDS). GHS hazard classification (H-statements, pictograms) is cross-checked against publicly available manufacturer SDS for the specific product family. Where SDS values differ between manufacturers, we use the most conservative classification.
- UK Health Security Agency (UKHSA) Compendium of Chemical Hazards. Emergency procedures and health effects reference UKHSA guidance where available.
- Peer-reviewed medical literature. For known occupational sensitisers (PPD, persulphates, MMA, formaldehyde), health effects and sensitisation risk reference peer-reviewed journals via PubMed Central and the Journal of Occupational Medicine.
- HSE trade-specific guidance.For sectors HSE has published specific guidance on (hairdressing, cleaning, construction), sector-specific control recommendations are drawn from HSE's published pages.
2. Editorial process
Each substance entry passes through this workflow:
- Initial draft compiled from primary sources listed above.
- Cross-check WEL values against EH40/2005 Table 1. Values that cannot be verified are marked "Not established" rather than guessed.
- Cross-check GHS classification against at least 2 manufacturer SDS.
- Emergency procedures written to follow the UK 999 / NHS 111 / TOXBASE structure.
- Control measures listed in HSE hierarchy of control order (elimination, substitution, engineering, admin, PPE).
- Full entry reviewed for consistency with COSHH 2002 legal wording.
3. What we mark as "Not established"
Where a Workplace Exposure Limit has not been set by HSE for a specific substance, the WEL field in the generated PDF shows Not established rather than a fabricated number. This is common for substances where hazard is controlled by other means (skin corrosives with no meaningful airborne exposure route, for example). In these cases, the assessment PDF includes explanatory notes about how to control exposure without a formal air limit.
4. What we do not do
- We do not fabricate WEL values where none exists in HSE EH40.
- We do not copy-paste emergency procedures across substances. Every emergency procedure is substance-specific.
- We do not represent our tool as HSE-approved. No online tool is HSE-approved.
- We do not include substances outside our verified library. The library is deliberately smaller than 500-substance enterprise tools so that every entry is verified.
5. Update schedule
The substance library is reviewed:
- Immediately when HSE publishes an updated EH40 revision (typically annual).
- When a paying customer reports that data appears inconsistent with their manufacturer's SDS.
- When new UK legislation affects COSHH obligations.
- Ad-hoc when new peer-reviewed evidence emerges for known occupational sensitisers.
6. Corrections
If you spot data in a generated COSHH assessment that appears inconsistent with the manufacturer SDS of your specific product, or with current HSE guidance, email info@coshhassessments.co.uk with the substance name and the specific field. We will verify against primary sources and update the library. Corrections are actioned within 5 UK business days.
7. Legal position
This methodology describes how we build the tool. It does not remove the employer's legal responsibility under COSHH 2002. Every generated assessment must be reviewed by a competent person, cross-checked against the specific product's Safety Data Sheet, and confirmed as suitable and sufficient for the specific workplace before being relied upon.