Number of parts of a substance found in one billion parts of a particular gas, liquid, or solid.

A unit of concentration.

A way of expressing the concentration of a substance in air, water, soil or food. A microgram per kilogram is the same as one part per billion. One ppb means that there is one part of a substance for [..]

Number of parts of a chemical found in one billion parts of a particular gas, liquid, or solid mixture. See concentration.

A unit frequently used to measure contamination concentration (parts of contamination per billion parts of water). One thousand parts per billion is equal to one part per million.

Parts per billion is a commonly used unit of concentration for very small values. One part per billion is one part of solute per one billion parts solvent.

Number of parts of a chemical found in one billion parts of a particular gas, liquid, or solid mixture. parts per million (ppm)

the number of "parts" by weight of a substance per billion parts of water. Used to measure extremely small concentrations.

Expressed as ppb; a unit of concentration equivalent to the µg/l.

A unit of measure used to describe levels or concentrations of contamination.   A measure of concentration, equaling 0.0000001 percent.  For example, One part per billion is the equivalent of one drop of impurity in 500 barrels of water.  Most drinking water standards are ppb concentrations. 

A unit of measure used for very small quantities, it is equal to the ratio of the weight or volume of one component of a mixture to a billion weights or volumes of the mixture. When based on weight (p [..]

µg/l, a measurement of concentration on a weight or volume basis. This term is equivalent to micrograms per liter. Parts Per Million (PPM)

The number of "parts" by weight of a substance per billion parts of water. Used to measure extremely small concentrations.

A unit of measurement of concentration: a concentration of 1 ppb by volume (also symbolized ppbv) means one unit of volume of one substance (such as a pollutant) in every billion (109) of the same uni [..]

Represents the concentration of something in water or soil. One ppb represents one microgram of something per liter of water (ug/l), or one microgram of something per kilogram of soil (ug/kg).

Unit commonly used to express concentrations of contamination and ppb is 1/1,000,000,000. An example is 0.005 ppm equals 5 ppb.

A unit of measure used to describe levels or concentrations of contamination. A measure of concentration, equaling 0.0000001 percent. For example, One part per billion is the equivalent of one drop of [..]