I have done some research Eamonn and it seems we are both providing information that is at best incomplete and at worst incorrect. I have read the information in the link you provided and to quote from it:
"FFP1, FFP2 and FFP3 are designed to filter out dust only. They must not be used where there is an oxygen-deficient atmosphere or harmful gases and vapours."
From further research on the HSE website it seems an FFP3 rated filter will, at best, provide limited protection and what is required is a gas and vapour rated filter. These will not normally also protect against dust unless specified. To further complicate matters and to quote the HSE document below: "Filters are available for situations where protection is needed against both particles and specific gases or vapours. This type of filter will carry markings for particles and vapours, eg A2P3"
See Appendix 1 (pp 28 et seq) of the HSE document Respiratory protective equipment at work. A practical guide
Having said all of that 99% of pen makers will no doubt carry on regardless with no protection at all but at least I can now safely say I am not misleading anyone.
