What is OSHA permissible exposure limits?
OSHA permissible exposure limits, or PELs, are legally enforceable US limits on the amount or concentration of a substance in the air that workers may be exposed to, usually expressed as an eight-hour time-weighted average, with some short-term and ceiling limits. They are set by the Occupational Safety and Health Administration.
What it is
PELs cover hundreds of chemicals, dusts and other airborne contaminants. Most general industry limits are listed in OSHA's air contaminants tables, and some substances have their own standards with additional requirements.
Limits are usually time-weighted averages over a shift. Some substances also have short-term exposure limits or ceiling values that must not be exceeded at any time.
Many PELs date from OSHA's early years. Employers often also consider more recent recommendations, such as those from NIOSH or ACGIH, while PELs remain the enforceable limits.
Who it applies to
US employers covered by OSHA, particularly in manufacturing, processing, food and dairy plants, laboratories and maintenance operations. State plan states may have their own limits.
Environmental health and safety teams own exposure assessment and compliance.
How it is measured
Compliance is assessed through exposure monitoring, typically personal sampling in the worker's breathing zone, by qualified professionals.
- Personal air sampling results
- Area monitoring of contaminants
- Process and ventilation conditions during sampling
- Records of controls and corrective actions
How Aqueduct helps
Aqueduct supplies continuous plant air records during production. Aqueduct supplies the measurements; your EHS team owns compliance.
- aQ AirSafe area sensing for particulates, VOCs and gases where suitable sensors exist
- Trends tied to production runs and ventilation state
- Excursions flagged and routed to your team
- Records that support, but do not replace, personal exposure sampling