ppb

Units & Measurements abbreviation · Engineering Unit

ppb
Stands forParts per billion
CategoriesUnits & Measurements

ppb stands for Parts per billion, an engineering unit abbreviation.

Concentration ratio of one part in a billion, used for trace contaminants such as lead and arsenic in drinking water, ozone in air and pesticide residues. One ppb in water is about one microgram per liter.

Example: Lead in the sample was 7 ppb, below the federal action level.

Usage notes

The US ozone air-quality standard is 70 ppb averaged over eight hours, and atmospheric methane is roughly 1,900 ppb. Some contaminants are regulated at even lower levels in parts per trillion (ppt), such as the EPA's 4 ppt drinking-water limits for the PFAS chemicals PFOA and PFOS.

More engineering unit abbreviations

  • mV – Millivolt
  • MW – Megawatt
  • MWh – Megawatt-hour
  • Nm – Newton-meter
  • NPT – National Pipe Thread
  • Pa – Pascal
  • ppm – Parts per million
  • PS – Pferdestärke (metric horsepower)
  • psi – Pounds per square inch
  • psia – Pounds per square inch absolute
  • psig – Pounds per square inch gauge
  • R – Degree Rankine

See all 103 engineering unit abbreviations →

Edited by the AbbreviationList.com team. Spotted an error or a missing meaning? Contact us.