Research at Seattle's University of Washington has come up with a way of identifying the toxicity of chemicals used as anti-wear additives in aero-engine oil, potentially cutting the risk of passengers and crew suffering so-called "aerotoxic syndrome" when oil fumes enter into the cabin air conditioning system.
The organophosphate tri-cresyl phosphate (TCP) is an essential component of the aero-engine oil anti-wear additive, and it has long been accepted that certain organophosphates are neurotoxins. Professor of genome sciences and medicine Clement Furlong, of the university's School of Medicine, explains that he has proven a test for identifying neurologically-harmful isomers of TCP, as well as establishing which ones cause less harm.
While oil manufacturers have tried to reduce the presence of the tri-ortho-cresyl phosphate (TOCP) isomer - known to be toxic - to low levels in oil additives, other TCP isomers, present in large quantities but previously thought to be benign, are, in fact, a worse danger to the human nervous system than TOCP.
Furlong has shown that butyrylcholinesterase, a naturally occurring protein in the human neurological system, can have its function inhibited by certain isomers of TCP. But he states that a different TCP isomer (tert-butyl phenyl phosphate) produced the "least inhibition", according to a laboratory screening test of the potential toxicity of the phosphates.
When tested on mice, Furlong says the chemicals continued to demonstrate a similar degree of neurological harm.
In addition, Furlong has discovered that extracts from grapefruit can reduce the harmful effects of TCPs.