This article relies largely or entirely on a single source. (July 2009)
A paint thinner is a solvent used to thin oil-based paints or clean up after their use. Commercially, solvents labeled "Paint Thinner" are usually mineral spirits having a flash point at about 40 °C (104 °F), the same as some popular brands of charcoal starter.
Common solvents used as paint thinners include:
- Mineral spirits (US) / White spirit (UK)
- Methyl ethyl ketone (MEK)
- Dimethylformamide (DMF)
- 2-Butoxyethanol, or any of the other glycol ethers
Less common solvents used as paint thinner include: 
Exposure to vapors created by paint containing thinner or its clean up may be hazardous. The American Conference of Governmental Industrial Hygienists has established threshold limit values (TLVs) for most of these compounds. TLV is defined as the maximum concentration in air which can be breathed by a normal person (i.e., excluding children, pregnant women, etc.) in the course of 40 hours work (in US work conditions) per week, day after day through their work life without long-term ill effects. In underdeveloped countries workers commonly experience much higher exposure to these chemicals with consequent damage to their health.