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Exposure Limits for Synthetic Mineral Fibers


AGENCY/SUBSTANCE

OSHA PEL - TWA

*Mineral fibers are currently only regulated as nuisance dust

General Industry
Inert or Nuisance Dust
(1910.1000, Table Z-3)


Respirable fraction: 5 mg/m3
Total dust: 15 mg/m3

Shipyard
Fibrous Glass (1915.1000, Table Z)


Respirable fraction: 5 mg/m3
Total dust: 15 mg/m3

Shipyard
Mineral Wool (1915.1000, Table Z)


Respirable fraction: 5 mg/m3
Total dust: 15 mg/m3

ACGIH TLV - TWA

Synthetic Vitreous Fibers Continuous filament glass fibers*, A4: 1 f/cc
Continuous filament glass fibers**, A4: 5 mg/m3
Glass wool fibers*, A3: 1 f/cc
Rock wool fibers*, A3: 1 f/cc
Slag wool fibers*, A3: 1 f/cc
Special purpose glass fibers*, A3: 1 f/cc
Refractory ceramic fibers*, A2: 0.2 f/cc(1)

* Fibers longer than 5 µm; diameter less than 3 µm; aspect ratio greater than 5:1 as determined by the membrane filter method at 400-450X magnification (4-mm objective) phase contrast illumination.
**Inhalable fraction. The concentration of inhalable particulate for the application of this TLV is to be determined from the fraction passing a size-selector with characteristics defined in the "A" paragraph of Appendix D.
A2 Suspected Human Carcinogen.
A3 Confirmed Animal Carcinogen with Unknown Relevance to Humans.
A4 Not Classifiable as a Human Carcinogen.

NIOSH REL - TWA

Fibrous Glass Dust (1977 Proposal) Total dust: 5 mg/m3
Fibers with diameter equal or less than 3.5 µm;, and length equal to or greater than 10 µm: 3 f/cc

HSPP Voluntary Exposure Limit - TWA

Synthetic Vitreous Fibers 1 f/cc

National Academy of Sciences
Recommended Exposure Level - TWA

Manufactured Vitreous Fibers 1 f/cc

State of California's Established PEL - TWA

Synthetic Vitreous Fibers 1 f/cc

(1) ACGIH Statement of Position Regarding the TLVs® and BEIs®

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