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Chemistry and Toxicology of Mobil Jet Oil II. Prof Chris Winder School of Safety Science University of New South Wales, Sydney, Australia. The Engine Oil. All Jet oils are fairly similar in content Based on a synthetic polyol oil base, such as derivatives of erythritol.
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Chemistry and Toxicology of Mobil Jet Oil II Prof Chris WinderSchool of Safety Science University of New South Wales, Sydney, Australia
The Engine Oil • All Jet oils are fairly similar in content • Based on a synthetic polyol oil base, such as derivatives of erythritol • Contain various additives to enhance performance, including • A substituted diphenylamine, added as an antioxidant • Tricresyl phosphate added to prevent metal wear and as a fire retardant • N-Phenyl-1-naphthylamine (PAN) is an antioxidant
The Substituted Diphenylamine • The substituted diphenylamine is added as an oxidant • Added at a concentration of about 1% • Considered hazardous to the environment (properties of poor biodegradability and toxicity to aquatic invertebrates)
N-Phenyl-1-naphthylamine • N-phenyl-1-naphthylamine (PAN) is a sensitiser in animals and exposed workers • The contaminant 2-naphthylamine is a carcinogen • Lung and kidney cancer reported in animals and workers exposed to an oil containing 0.5-1 % PAN • Not known if concentration of PAN in jet oil (1%) is a carcinogenic risk • PAN is considered a skin sensitisation risk
Tricresyl Phosphate • Tricresyl phosphate (TCP) has an organophosphate structure, with three cresyl groups attached to a phosphate group ortho Tri-OCP: ooo Di-OCP: oop oom Mono-OCP: opp opm omm Non-OCP: ppp ppm pmm mmm meta para
Tricresyl Phosphate • TCP is a mixture of ten isomers from combinations of ortho, meta and para cresyl groups • Added to oils at a concentration of about 3% • No alternative product available • The addition to aviation oil is one of the last commercial uses of tricresyl phosphate
Tricresyl Phosphate • 1958 German studies show: • DOCP (o,o,?) isomers 5 times more toxic than TOCP • MOCP (o,?,?) isomers 10 times more toxic than TOCP • other toxic organophosphate structures may also be present • Manufacturer admits to -OCP levels in oil • Significant efforts have been made to reduce -OCP concentrations in commercial grades of TCP • Not known if levels of -OCP in older jet oils has changed (a complex approval process exists in aviation)
Tricresyl Phosphate • Manufacturer admits in documentation to TOCP levels in oil of 5 ppb (0.005 ppm) • Evidence to Senate Inquiry also admitted to6 ppm DOCPs and 3070 ppm MOCPs Isomer Conc Rel Tox Equiv Tox TOCP 0.005 ppm 1 1 × DOCPs 6 ppm 5 × 30 × MOCPs 3070 ppm 10 × 30700 × Total 30731 × Other O-OPs ? ppm ? × ? ×
The MSDS This product is not expected to produce adverse health effects under normal conditions of use and with appropriate personal hygiene practices. Product may decompose at elevated temperatures or under fire conditions and give off irritating and/or harmful (carbon monoxide) gases/vapours/ fumes. Symptoms from acute exposure to these decomposition products in confined spaces may include headache, nausea, eye, nose, and throat irritation.
Features of the HSR Classification Process: The Designated List • Published by Worksafe in 1994 • 1,300 Hazardous substances • Guidance on sub-categories, cut off values, risk and safety phrases • Re-published in 1999 • Contained about 2,200 entries • Replaced by HSIS in 2005
Features of the HSR Classification Process: The Approved Criteria • Published by Worksafe in 1994 (and 1999) • Classification criteria endpoints for: • Death after a single exposure • Toxicity after single exposure (not death) • Toxicity after repeated exposures • Irritation • Corrosiveness • Sensitisation • Effects on genetic material • Effects on reproduction • Cancer • Aspiration hazard • Other toxic properties • Replaced by HSIS in 2005 TCP meets criteria PAN meets criteria
Mobil Jet Oil II Warning (pre-1998) Warning (post-1998)
What they say • Mobil Oil“the jet oil used in these engines is not hazardous” “the jet oil is not hazardous under normal conditions of use” “Mobil does not believe that Mobil Jet turbine oils pose any significant toxicological risk to individuals accidentally exposed to aerosols or vapours in aircraft cabins. Such exposures are not what we would refer to as ‘normal use’ but the cabin levels that can be reached during such exposures … are considered safe” “TCP is not hazardous; concentrations of TOCP are very low”
Summary: Toxicity of the Oil • Contains at least two toxic ingredients • -OCP isomers known neurotoxicants • PAN a known sensitiser • Manufacturer only partially disclosing toxic ingredients • Concentration of -OCP sufficient to satisfy classification of product as a neurotoxicant, if toxicity equivalents used (10,000 ppm or 1%) • Concentration of PAN sufficient to satisfy classification of product as a sensitiser (1%)