The pH of halogenated solvents varies according to the nature of stabilizers in the particular solvent. Solvents with alkaline stabilizers (amine-types) generally have pHs in the 7 to 11 range, whereas solvents containing neutral stabilizers (epoxide-types) generally have pHs in the 5 to 7 range.

Virgin and reclaimed solvents should have pHs within these ranges, dependent upon the claimed method of stabilization. These values should be within the accepted limits as proposed by the producers of the original virgin solvent.

A lowering of pH from the above values, on receipt or use, is cause for concern. In this event, solvents having epoxide stabilizers should be tested for acid acceptance; solvent having alkaline stabilizers should be tested for alkalinity.

1.1 This test method covers the measurement of the pH of water extractions of halogenated organic solvents and admixtures thereof. This test method is applicable for the determination of the pH of water extractions of virgin, reclaimed, or used solvents.

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.