I just used once a common solvent for cleaning my brushes and it left me with terrible headache. Luckily in my very beginning as an oil painter I met Gary and he gave me a priceless tip.
Here is the info from Gamblin website.
GAMSOL Odorless Mineral Spirits
Gamsol is the safest solvent that allows oil painters to utilize all traditional painting techniques without compromise.
Primary Uses for Gamsol:
- Thinning oil colors. A little goes a long way; stiff oil colors relax immediately when a little Gamsol is added. Be careful not to thin oil colors too much with solvent alone, this can compromise the ability of the paint to form a paint film.
- Modifying painting mediums. Our Galkyd line of painting mediums are formulated with Gamsol, so they readily accept Gamsol as a thinning agent. Note: Gamsol should not be added to painting mediums made with natural resins (dammar, copal, mastic). They require strong solvents such as turpentine.
- Studio clean up: brushes, palettes, palette knives, etc.
How does Gamsol achieve this level of performance and safety? Most solvents available to artists come from the industrial paint industry where solvent power and cheapness is prized. Gamsol is special: it is made for products and processes that come into more intimate contact with the body such as cosmetics, hand cleaners, and cleaning food service equipment.
Gamsol is a petroleum distillate but all the aromatic solvents have been refined out of it, less than .005% remains. Aromatic solvents are the most harmful types of petroleum solvents.
These facts are detailed in the SDS for Gamsol, this document shows that it has an Exposure Limit Value higher than most solvents available to artists. In addition, Gamsol’s flash point is so high it can ship via air cargo as a non-hazardous material.
All of these factors have lead to Gamsol being used widely in oil painting classrooms; in those classes there are no solvent odors, only the wonderful smell of oil colors.