STEL13
STEL13 : Short-Term Exposure Limit. The concentration to which it is believed that workers can be exposed continuously for a short period of time, usually 15 minutes, without suffering from irritation, chronic or irreversible tissue damage, or narcosis of sufficient degree to increase the likelihood of accidental injury, impair self-rescue, or materially reduce work efficiency; provided that the 8-hr. TWA is not exceeded