OEL reference across 12 jurisdictions · 8-hr TWA calculator with shift adjustment · Mixture hazard index
How to use: Search by chemical name or CAS number. The table shows occupational exposure limits across 12 jurisdictions. Optionally enter a measured exposure value to compare compliance against each standard.
Loading substance database…
687 substances · 12 jurisdiction tables
Measured exposure (optional)
Enter your measured exposure and select the OEL type to compare against each jurisdiction.
Show jurisdictions
Jurisdiction
TWA ppm
TWA mg/m³
STEL ppm
STEL mg/m³
Ceiling
Notations
Status
No OEL data found for that substance.
Try searching by CAS number, or check for alternate names.
How to use: Search for a chemical to load its OELs, then add exposure periods (task description, measured concentration, and duration). The 8-hour TWA is calculated and compared against each jurisdiction's limit. Enable shift adjustment to apply a reduction factor for extended work schedules.
Chemical
Unit:
Exposure periods
Task / description
Concentration (ppm)
Hours
Minutes
Shift adjustmentOff — standard 8 hr/day, 5 day/week
Adjustment model
No adjustment if t½ < 4 hr or t½ > 400 hr.
8-hour TWA
—ppm
Total duration
—
Also
—mg/m³
OEL Comparison
Jurisdiction
TWA OEL
STEL / Ceiling
% of OEL
Status
Notation
Search for a chemical above to compare against OELs.
Add an exposure period above to begin.
Additive mixture model: When two or more substances share the same critical health effect or target organ, their combined effect is assessed by the Hazard Index: HI = Σ(Ci / OELi). If HI > 1, the mixture OEL equivalent is exceeded. You must verify that substances share a common target organ before applying this model. For substances with independent effects, assess each against its own OEL using Tool 2.
Jurisdiction
Measurement unit
Add substance
Substance
Measured TWA
Unit
OEL (selected jurisdiction)
Ci / OELi
Add at least two substances to assess mixture toxicity.