Definition - What does Flammable mean?
Flammable refers to a property of liquids, solids or compounds that catch fire and how quickly or easily this happens. In terms of occupational health and safety, flammable liquids and gases are often of greatest concern, because they tend to be the most volatile and storing them in a fire-safe way is more difficult.
Safeopedia explains Flammable
According to OSHA, a liquid is considered to be flammable when its flash point is below 100°F (37.8°C). For example, ethyl ether (a solvent) has a flash point of -49°F. Flammable should not be confused with combustible, which refers to liquids with a flash point above 100°F, such as fuel oil, mineral oil and paint.