Ultra-Trace Chemistry August 15, 2026

Parts Per Trillion (PPT) to PPB and PPM: Ultra-Trace Chemistry

How to convert parts per trillion (PPT) into PPB and PPM when analyzing emerging contaminants like PFAS.

Sarah Jenkins, MS

Environmental Science Specialist

Parts Per Trillion (PPT) to PPB and PPM

Parts per trillion (PPT) is an ultra-trace unit of concentration:

1 PPT = 0.001 PPB = 0.000001 PPM = 1 ng/L

Emerging water safety regulations, including EPA maximum contaminant levels for PFAS compounds (PFOA and PFOS), require laboratory detection limits down to single-digit parts per trillion.

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