Products with Workplace Exposure Limits
Workplace Exposure Limits are provided to ensure that workers are not exposed to high levels of hazardous substances which might adversely affect their health. For more details, see https://ttenvironmenta.wpengine.com/clp-knowledgebase/chemicals-with-workplace-exposure-limits/ .
Products with Workplace Exposure Limits – placing on the market
Substances or mixtures which hold Workplace Exposure Limits, WELs, may either be classified as hazardous under CLP, or classified as non-hazardous.
In the latter case, where an SDS is not normally required, an SDS is required where a WEL is present at or above 0.1% w/w.
A substance which holds a WEL must be listed on the SDS in section 3.1 (substance or impurity at 1% w/w or greater), or section 3.2 (component substance at 1% w/w or greater). However, such a substance does not explicitly have to be identified as a WEL in section 3.1 or 3.2 of the SDS, but it will be identified as such in section 8.1 of the SDS. Some SDS authors prefer to identify WELs in section 3.1 or 3.2 as well as in section 8.1, as a courtesy to their readers.
There is some debate in the regulatory affairs community about how WELs of component substances in mixtures should be handled on the SDS where they do not affect the hazard classification of the mixture in its normal form. This particularly affects a component substance which holds a WEL for dust inhalation, but is contained in a mixture which is aqueous solution, meaning that there is no risk in the product as it is supplied. However, if the product is dried out, the WEL risk could return. Obviously, the WEL risk will be identified in Section 8.1 of the SDS anyway, but some SDS authors consider it good practice to include the WEL information in Section 2.3 of the SDS, with a note to the effect “Contains xxx in solution, which has a Workplace Exposure Limit. If the mixture dries out, there may be inhalation risks from this substance”.
Products with Workplace Exposure Limits – downstream user
As a downstream user, you (or your Health and Safety person) should identify all products with Workplace Exposure Limits (WELs), and ensure that the conditions of the WEL are complied with so that your workforce is not exposed to illegally high concentrations of the substance. Substances may have two sets of WELs, a set of EU limits, and a set of national limits, which supersede the EU limits in the specific country where the substance is used.
You can check for any WELs on the substance or mixture in Section 8.1 of the SDS, where these should be listed for the substance itself, or for the mixture components, where all the WELs (EU and national) should be listed for each substance holding a WEL. Note that the national limits will be given in Section 8.1 if they supersede the EU limits. It is possible that WEL substances may also be included in Section 2.3 of the SDS, under “other hazards”.
If you want to confirm this information for yourself, the names (and CAS numbers) of substances with WELs, and the WEL limits for the UK, are given in HSE guide EH40/2005, Workplace Exposure Limits (2011 edition with updates), which can be downloaded for free as a pdf from http://www.hse.gov.uk/pubns/priced/eh40.pdf .
If the product supplied to you is classified as hazardous, you should automatically receive an SDS, which can be checked in Section 8.1 to see whether any WELs apply to the substance, or component substances. Many companies supply SDSs automatically for non-CLP classified products which contain components with WELs, although theoretically this is only required at the request of the downstream user.
If you, as an industrial or professional user and receive a product which is not classified for CLP, without receiving an SDS, you are able to request one, and are entitled to receive a copy in certain circumstances, including if the product has or contains a WEL at any concentration. If the supplier declines to issue you with an SDS to enable you to check, this may be because the product is non-classified, and does not require an SDS for any other reason, in which case it is probably safe to assume that no WELs apply to the product.