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21 Day Repeated Dose Dermal Toxicity Study of Aircraft Engine Oils Using Sprague Dawley Rats (Rattus Norvegicus): Effects on Organs, Hematological Parameters and Cholinesterase Enzyme Activities in Tissues and Blood

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Technical Report,01 Dec 2017,30 Apr 2020

Corporate Author:

Henry M. Jackson Foundation for the Advancement of Military Medicine Wright-Patterson AFB

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This study was conducted to determine if two MIL-PRF-7808 aircraft engine oils grade 3 G3 and grade 4 G4 in their new states G3-N and G4-N and their used versions G3-U and G4-U have potential to induce toxicity via dermal application. Male and female Sprague Dawley rats were dermally exposed to water control, new and used versions of G3 and G4 oils. A volume of 300L of undiluted oil was applied to a pad in the Hill Top Chamber System. The chamber was attached to a fur-free test site on the back of a rat for 6 hday, 5 consecutive daysweek for 21 days 15 total exposures. Recovery rats exposed the same were kept for 14 days post-exposure to screen for reversibility, persistence, or delayed occurrence of toxic effects. A pilot study, with rats receiving the same treatment, was conducted to characterize electrophysiological effects associated with exposure to these oils. Oil analysis by 31P NMR indicated that G3 oils contained 4 isomers of tricresyl phosphates TCP while G4 comprised phenol isopropylated phosphate 31 PIPand triphenyl phosphate TPP. The concentration for TCP in G3-U decreased by 26 relative to G3-N while amounts of TPP and PIP in G4-U decreased by 22 and 6.4, respectively, relative to G4-N. Both G3 and G4 oils had a significant impact on weight of male and female reproductive organs testes of G3-N recovery rats decreased uterus of G3-N and G3-U rats decreased uterus of G4-N rats decreased but recovered G4-N increased weight of adrenals and spleen for females during recovery. G4-N induced the most changes in profiles of female blood, significantly decreasing white blood cells, lymphocytes, neutrophils, eosinophils and increasing mean platelet volumes. Males were not affected by exposure to G4-N oil. While G3-N decreased white blood cells and lymphocytes for females, it slightly increased those for males.

Subject Categories:

  • Lubricants and Hydraulic Fluids
  • Toxicology
  • Anatomy and Physiology

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