Ppb

Parts per billion (ppb) is a measure of concentration that is used where low levels of concentration are significant. As the name implies, one ppb is the same as 1/1 000 000 000 or 10^-7%. The ppm value is equivalent to the absolute fractional amount multiplied by one billion (10⁹). You can read more about ppm and other similar units under concentration.

Similar units:

• Parts per million (ppm).
• Parts per trillion (ppt).