What are odorless mineral spirits (OMS)?
OMS is a safer substitute for mineral spirits or turpentine. It is petroleum distillate. There are two components to petroleum distillate: aromatic and aliphatic. The more toxic aromatic hydrocarbons have been reduced or removed, hence the milder odor. Since turpentine evaporates quicker than mineral spirits, high concentrations of aromatic components can become hazardous more quickly with turpentine than with mineral spirits. Turpentine is also more flammable than mineral spirits. OMS is preferred over turpentine because of lower toxicity, lower volatility, and lower flammability. If you use a medium based on damar varnish, you must use turpentine to make your medium. If you add OMS to damar varnish, the resin will drop out of solution and cloud the medium. If you see a commercially prepared damar varnish or damar/turpentine medium that is cloudy, select another brand. Even if you use turpentine in your painting medium, use OMS for brush and studio clean up.
