Experimental Human Exposure to Vapor of Propylene Glycol Monomethyl Ether

Abstract

The monomethyl ether of propylene glycol (PGME) is used as a radiator coolant Simulation of PGME coolant leakage on the engine of an idling truck resulted in a breathing zone concentration of 5 ppm in the cab. Under grossly exaggerated leakage conditions, a concentration of 460 ppm was reached when the coolant was pumped into the heater of an unventilated truck cab. In controlled human exposure studies to PQME vapor concentrations ranging from 50 to 2,000 ppm, the odor became transiently objectionable above 100 ppm. Eye, nasal, and throat irriation became objectionable prior to the first signs of central nervous system (CNS) impairment, which occurred at 1,000 ppm in one of two subjects. Alveolar breath samples must be obtained within 10 to 20 minutes following exposure because of the rapid decrease in solvent concentration.