“A Method Of Expressing Low Concentrations. 1 Ppm Is Equival…

“A Method Of Expressing Low Concentrations. 1 Ppm Is Equivalent To 1 Milligram Per Liter. In Contaminated Air, The Parts Of Vapor Or Gas (Formaldehyde) Per Million Parts Of Air By Volume And In Solution The Parts Of Chemical Per Million Parts Of Solution.” is the definition of?