Use of Environmental Forensics In Drycleaning Investigations

Distinguishing Drycleaner fromTransformer/Metal Cleaning PCE (a)PCE was used in transformers as a replacement for the more toxic class of dielectricfluids containing PCBs.PCE used as a dielectric fluid was subjected to extra refining including scrubbing anddistillation and was stabilized with n-methyl pyrrole (112 C) and pentaphen (p-tert amylphenol) (226 C).Drycleaning grades of PCE did not use n-methyl pyrrole or pentaphen. May use thepresence of these two stabilizers with PCE to distinguish PCE originating from adrycleaners from one originating from a transformer.Patent literature indicates that metal degreasing metal cleaningPCE used n-methyl pyrrole as an oxidant containing 0.022 to0.028% stabilizer andnot for dry cleaning.N-methyl pyrrole was also used to stabilize TCA and TCE;pentaphen used to stabilize TCE against oxidation.