Highlights

  • Aircraft engine oil and hydraulic fluid can degrade at temperatures above 300 °C, and generate CO when in contact with hot metal surfaces.
  • The most common signs and symptoms of chronic carbon monoxide (CO) intoxication are nonspecific and include headache, dizziness, lethargy, cognitive impairment, and confusion.
  • In at least 129 of 888 (14.5%) flights, CO levels were ranging from 13-60 ppm.
  • Guidelines for CO-exposure limits established at sea level may not be suitable for aviation circumstances.
  • An occupational exposure limit of 5 ppm (8 hr TWA) for aircrew is recommended.

https://www.sciencedirect.com/science/article/abs/pii/S0161813X23001791