Work out short term exposure limit instantly with clear inputs, formula shown and shareable results.
A short term exposure limit is a fifteen minute time weighted average that must not be exceeded at any point in the shift, even where the eight hour average is compliant. Conventional practice also limits excursions to four per shift, each no longer than fifteen minutes and separated by at least sixty minutes.
STEL check
Ratio = peak fifteen minute concentration / STEL
Excursion rule
No more than four excursions of 15 minutes each, at least 60 minutes apart
Preliminary estimate only. Short term limits and excursion rules must be taken from the exposure limit list adopted by your regulator.
Ratio = peak fifteen minute concentration / STEL. A short term exposure limit is a fifteen minute time weighted average that must not be exceeded at any point in the shift, even where the eight hour average is compliant.
The excursion limit applies instead: exposure should not exceed three times the eight hour limit for more than thirty minutes, and never five times the limit.
This calculator takes 4 inputs: Peak concentration measured, Short term exposure limit, Duration of the peak, Excursions per shift. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.