<< Back to 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
       Total dust
5 mg/m3
15 mg/m3
Shipyard
Fibrous Glass (1915.1000, Table Z)
      Respirable fraction
      Total dust
5 mg/m3
15 mg/m3
Shipyard
Mineral Wool (1915.1000, Table Z)
      Respirable dust
      Total dust
5 mg/m3
15 mg/m3
ACGIH TLV - TWA
Synthetic Vitreous Fibers
     Continuous filament glass fibers*, A4
     Continuous filament glass fibers**, A4
     Glass wool fibers*, A3
     Rock wool fibers*, A3
     Slag wool fibers*, A3
     Special purpose glass fibers*, A3
     Refractory ceramic fibers*, A2
1 f/cc 
5 mg/m3
1 f/cc 
1 f/cc 
1 f/cc 
1 f/cc 
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
      Fibers with diameter equal or
      less than 3.5 µm;, and length
      equal to or greater than 10 µm;

5 mg/m3
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