I have two - both from Screwfix - one for dust and one for solvents - both have replaceable filters - the dust one was £25 and the solvent one £35.

I have one from 3M, works great and fits perfectly.

I use it for all sorts of jobs (sanding, painting,...)

Louis

My masks

This one does solvents - did some priming on a pedal and it kept out the smell from a rattle can.

This is for dust - again does what it says on the tin.

@frank1985

I'm not sure where you live for sourcing a respirator. I was a qualified Health & Safety manager doing risk assessments for all types of Worksop tasks including PPE, masks, gloves etc. and belonged to a professional safety body until I retired last year,  so am well experienced in finding and sourcing the correct mask.

If you are in the UK try Arco it's one of the best suppliers. Masks are in different sizes so you have to get small, medium or large to make an air tight seal around the face. There is a test for this but it's expensive. 3M is a good reliable make, which is available all over the world, with disposable filters which vary according to the hazard. Filters are colour coded for the particular hazard and the general rule is if you can smell the solvent through the mask then the filters need replacing. 

Check the HSE web site www.hse.gov.uk for guidance and just search respiratory protective equipment.

Thanks guys, I got the gvs a1p3 from arco in the end  . I nearly went for the p3 but this one handles organic vapours in addition to dust.