Parts per billion

Parts per billion (ppb) is a unit of measure by which concentration is measured. It refers to the number of units of a given substance (agent, etc.) that there are for every trillion units of the set. In this case the word is referred to billion Anglo-Saxon (see billion), which is equivalent to billion, that is, 1,000,000,000, or 10, in scientific notation. For example, in a billion rice grains, if one were painted black, this grain would represent one (1) part per billion. It is abbreviated as "ppb".

It is relatively frequent in the measurement of the concentration of highly diluted chemical compounds, as well as substances that are at trace level, such as impurities or contaminants.

The most common units in which they are used are the following: * Note: You put a v or an m at the end depending on whether they are parts by volume or by mass.

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