What is used to describe the weight of a liquid relative to water?

Specific gravity is the term used to describe the weight of a liquid relative to the weight of an equal volume of water. It is a dimensionless number that indicates how dense a substance is compared to water, which has a specific gravity of 1. If a liquid has a specific gravity less than 1, it will float on water, while a specific gravity greater than 1 indicates that the liquid is denser than water and will sink.

This measurement is important in a variety of fields, including hazardous materials handling, as it helps in identifying liquid substances and assessing their potential behavior in various situations, such as spills. Understanding specific gravity can assist responders in making informed decisions about containment, cleanup, and potential risks.

In this context, other terms such as flammable limit, vapor density, and flash point do not relate to describing the weight of a liquid in relation to water. Flammable limit refers to the concentration of a vapor in air that can ignite, vapor density compares the density of a vapor to air, and flash point defines the lowest temperature at which a substance can vaporize to form an ignitable mixture. These concepts are significant in hazardous materials handling but serve different purposes than specific gravity.