None established (ACGIH 1990-1991). Oxygen is the “vital element” in the atmosphere in which we live and breathe (approximately 21 molar % of the atmosphere). OSHA 1989 does not list a TWA for oxygen.
SYMPTOMS OF EXPOSURE
Breathing high concentrations (greater than 75 molar percent) causes symptoms of hyperoxia which includes cramps, nausea, dizziness, hypothermia, amblyopia, respiratory difficulties, and capable of leading to death.