specific gravity

Specific gravity is the ratio of the density (mass of a unit volume) of a substance to the density (mass of the same unit volume) of a reference substance (typically air and water). For example, Mercury has a specific gravity of 13.56, as it is 13.56 times as dense as water.

The density of water is about 1 gram per cubic centimeter (g/cc). Materials which are lighter than water (specific gravity less than 1.0) will float. Most materials have specific gravities exceeding 1.0, which means they are heavier than water and so will sink

Specific gravity may be relevant in transporting or processing this waste, and is entered as part of a waste profile. Similarly, the specific gravity is one of the physical properties entered for a chemical constituent listed in an SDS.

Knowing the specific gravity is important for planning spill clean-up and for fire-fighting procedures. For example, a light flammable liquid such as gasoline may spread and, if ignited, burn on top of a water surface.