Exposure Limits for Synthetic Mineral Fibers
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AGENCY/SUBSTANCE |
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OSHA PEL - TWA |
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|---|---|
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General Industry |
Respirable fraction: 15 mppcf* or 5 mg/m3 Total dust: 50 mppcf* or 15 mg/m3 |
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Construction Industry |
50 mppcf* (or 15 mg/m3 whichever is the smaller) of total dust <1% SiO2 |
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Shipyard |
Respirable fraction: 5 mg/m3 Total dust: 15 mg/m3 |
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Shipyard |
Respirable fraction: 5 mg/m3 Total dust: 15 mg/m3 |
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Shipyard |
50 mppcf* (or 15 mg/m3 whichever is the smaller) of total dust <1% SiO2 |
| *Millions of particles per cubic foot of air, based on impinger samples counted by light-field techniques. | |
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ACGIH TLV - TWA |
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| Synthetic Vitreous Fibers [1999](1) |
Continuous filament glass fibers** : 1 f/cc, A4 Continuous filament glass fibers*** : 5 mg/m3, A4 Glass wool fibers** : 1 f/cc, A3 Rock wool fibers** : 1 f/cc, A3 Slag wool fibers** : 1 f/cc, A3 Special purpose glass fibers** : 1 f/cc, A3 Refractory ceramic fibers** : 0.2 f/cc, A2 |
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**Respirable fibers > 5μm aspect ratio ≥ 3:1 as determined by the membrane filter method at 400-450X magnification (4mm objective), using phase contrast illumination. ***Inhalable particulate matter. 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 Appendix C, paragraph A of the ACGIH TLV book. A2 Suspected Human Carcinogen A3 Confirmed Animal Carcinogen with Unknown Relevance to Humans A4 Not Classifiable as a Human Carcinogen |
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NIOSH REL - TWA |
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| Fibrous glass dust, Mineral wool fiber (synthetic vitreous fibers) | 5 mg/m3 (total) 3 f/cm3 (fibers ≤ 3.5µm in diameter & ≥ 10μm in length) |
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State of California's Established PEL - TWA |
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| Fibrous glass (as Glass) | 1 f/cc(1) |
| Mineral wool fiber (as Particulates not otherwise regulated, or nuisance particulates) |
5 mg/m3 (total dust) |
(1) Fibers per cubic centimeter of air at 25°C and 760mm Hg pressure. To be considered a fiber for this limit the glass particle must be longer than 5µm, have a length to diameter ratio of three or more, and have a diameter less than 3μm. NIOSH Method 7400 (Issue 2, August 15, 1994) shall be used for measuring airborne fiber concentrations.
(2) The concentration and percentage of the particulate used for this limit are determined from the fraction passing a size selector with the following characteristics:
| Aerodynamic Diameter in Micrometers (unit density sphere) |
Percent Passing Selector |
|---|---|
| 0 | 100 |
| 1 | 97 |
| 2 | 91 |
| 3 | 74 |
| 4 | 50 |
| 5 | 30 |
| 6 | 17 |
| 7 | 9 |
| 8 | 5 |
| 10 | 1 |