Neurotoxin formation from pilot-scale incineration of synthetic ester turbine lubricants with a triaryl phosphate additive.

The high-temperature combustion of synthetic ester turbine engine lubricants has been performed by diluting the lubricant 5, 15, or 25% in diesel fuel and burning the mixture in a pilot-scale boiler facility. The effluent gas from this combustion system was carefully monitored for the formation of a potent neurotoxin, trimethylolpropane phosphate (TMPP). Although TMPP was not detected in the gaseous effluent, elevated levels of the neurotoxin were found in scrapings from the inside of the boiler system.

Potential neurotoxin formation in thermally degraded synthetic ester turbine lubricants.

Under extreme conditions of thermal degradation, a potent neurotoxin, trimethylolpropane phosphate (TMPP), may be formed by reaction of tricresyl phosphate (TCP, an anti-wear additive) and trimethylolpropane esters (TMPE) of carboxylic acids that may be contained in turbine engine lubricant formulations. The neurotoxin is only formed at extreme temperatures (350-700 degrees C), which has minimized concern for use of the synthetic lubricants under intended applications; however, since researchers are often not privy to the proprietary composition of such lubricants, extreme caution should be exercised in studies of or applications of synthetic lubricants degraded under extreme conditions.