Parts Per Million. PPM is a way of describing how much “stuff” is in a liquid. For example, if you have tap water with a ppm of 200, that means 200 parts per million parts of that tap water is minerals and other stuff.
- Parts per billion (PPB)
- Micrograms per gram (µg/g)
- Milligrams per kilogram (mg/kg)
- Parts per trillion (PPT)
- Parts per quadrillion (PPQ)