Summary
Propylene glycol is a chemical with the chemical identity and physical and chemical properties described in sections 3-1 and 3-2 of the provided document. It has been detected in air samples from a large scale environmental chamber, with quasi-steady-state emission rates of 690 µg/m2/hour and 193 µg/m2/hour at 24 hours and 168 hours after the start of the experiment, respectively. It was found to be present in cerebrospinal fluid (CSF) at 1 ppm using high-resolution proton nuclear magnetic resonance spectroscopy.
In humans, propylene glycol is rapidly absorbed by the gastrointestinal tract after oral exposure, with the maximum plasma concentration reached within 1 hour and an elimination half-life of about 4 hours. The total body clearance is about 0.1 L/kg/hour and appears to be serum concentration dependent. Dose-dependent elimination is also seen in rats.
No methods for reducing the body burden of propylene glycol after inhalation, oral, or dermal exposure were found. however, washing the skin with water after dermal exposure may reduce absorption.
There are toxicity studies of propylene glycol in laboratory animals in the literature, but they are not described in detail in the provided document.
Citation
Murray, Ed, and Julia George. “Toxicological Profile for Propylene Glycol.” USDhhS, September 1997.
