Ok, so you are carrying out your Coshh assessment you have an up to date MSDS. Where do you find the exposure limit if it is not on the MSDS or on HSE EH40 list. Are their other options for you to use to find the hazardous make up of the substance.

Last posting is correct, but sometimes the data from the manufacture’s data is not entirely useful for health and safety. I am based in the USA, so this may not be appropriate for you country...You could look at other counties limits, including USA and Canada. These are legal limits in their respective jurisdictions, however generally derived by science and perhaps a bit dated, so they can be useful. There are also scientifically set guidelines such as by NIOSH and the ACGIH. You may not be in fact, restricted from developing your own limits, as long as you have someone qualified. I have generated Material Safety Data Sheets for a previous employer with the help of a toxicologist, including setting scientific exposure limits. There is no shortage of scientific literature which the limits are set from. No shortage of limits out there.

Cheers

Your posting raises a number of points.

Firstly, exposure limits are only applicable for inhalation. They do not apply to the other two routes of exposure (ingestion and dermal).
Secondly, safety data sheets are for CHIP, not COSHH. They normally only show those constituents for which there are one or more risk phrases. Pargraph 13 of the ACoP for COSHH points out that this is not sufficient for COSHH. This is particularly the case for skin exposure. There are literally thousands of chemicals that do not have risk phrases but that, in contact with the skin, can cause damage to health. (Note, damage to health, not just skin disease!)
Thirdly, as an example of the above I can quote you at least five common sensitisers, so common that they are in most catalogues of patch test chemicals for the contact dermatitis clinic, that have not been listed as R43. They will not, therefore, generally be shown on the safety data sheet.
Fourthly, however, all is not lost! If you refer to the original Health and Safety at Work etc Act 1974 you will find in section 6-1 a requirement for the supplier to provide you with information on how to use his product safely for the purpose for which it has been supplied. So I always suggest that the person doing the risk assessment contacts the supplier to request information compliant with this part of the Act. Whether they are able to provide this information is, of course, another story!!
Chris

But WELs are in EH40. If it's not in EH40 it hasn't got a WEL.

Dust is of course in EH40.

My point is that all WELs are in EH40. If a substance doesn't have a WEL you may set an internal limit or guidance value based on other information such as already discussed - but that limit won't be a WEL, which is a legally binding limit.