WAX Liquidizer Wax Liquidizer is a proprietary blend of ingredients including Lab/Medical Grade PG PEG 200 and PEG 400. The ingredients PG and PEG are FDA approved as GRAS (Generally Recognized as Safe) they are found in many over the counter items including Asthma Inhalers, pop/soda and ice cream. PG is approved for human inhalation by the Environmental Protection Agency (EPA)