Specific gravity has a value relative to what?

Specific gravity is a dimensionless quantity that is used to compare the density of a substance to the density of a reference substance. In most contexts, including in the field of hazardous materials, the reference substance used is water.

Specific gravity is calculated by taking the density of the substance in question and dividing it by the density of water at a specified temperature (usually 4 degrees Celsius, where water has its maximum density). Since the density of water is approximately 1 g/cm³, any substance with a specific gravity greater than 1 is denser than water, while a specific gravity less than 1 indicates that it is less dense than water.

Understanding specific gravity is crucial for hazmat technicians, as it helps in determining how a hazardous material will behave in an aqueous environment, whether it will float or sink, which impacts its containment and cleanup strategies. This knowledge is fundamental when addressing spills or leaks of hazardous substances, as it aids in assessing the potential hazards and the necessary response measures.