Toluene is a clear, colorless liquid which becomes a vapor when exposed to air at room temperature. Toluene vapor has a sharp or sweet odor, which is a sign of exposure.
Toluene is typically used in a mixture with other solvents and chemicals such as paint pigments. Products that may contain toluene-such as paint, metal cleaners and adhesives-are used in many industries and can be found in many workplaces. Gasoline and other fuels also contain toluene. Workers using toluene-containing paints, varnishes, shellac, nail polish, glues and adhesives, rust preventives or printing inks may be exposed to toluene.
From OSHA
Toluene is a clear, colorless liquid which becomes a vapor when exposed to air at room temperature. Toluene vapor has a sharp or sweet odor, which is a sign of exposure.
Toluene is typically used in a mixture with other solvents and chemicals such as paint pigments. Products that may contain toluene-such as paint, metal cleaners and adhesives-are used in many industries and can be found in many workplaces. Gasoline and other fuels also contain toluene. Workers using toluene-containing paints, varnishes, shellac, nail polish, glues and adhesives, rust preventives or printing inks may be exposed to toluene.
https://www.osha.gov/toluene