# NIOSH Pocket Guide to Chemical Hazards
Fibrous glass dust | CAS
| RTECS LK3651000
Synonyms & Trade Names Fiber glas®, Fiberglass, Glass fibers, Glass wool [Note: Usually produced from borosilicate & low alkali silicate glasses.] | DOT ID & Guide
Exposure Limits | NIOSH REL: TWA 3 fibers/cm3 (fibers 3.5 m in diameter & 10 m in length) TWA 5 mg/m3 (total)
OSHA PEL: TWA 15 mg/m3 (total) TWA 5 mg/m3 (resp)
IDLH N.D. | Conversion
Physical Description Typically, glass filaments >3 m in diameter or glass "wool" with diameters down to 0.05 m & >1 m in length.
MW: NA | BP: NA | MLT: ? | Sol: Insoluble
VP: 0 mmHg (approx) | IP: NA |  | Sp.Gr: 2.5
Fl.P: NA | UEL: NA | LEL: NA |
Noncombustible Fibers
Incompatibilities & Reactivities None reported
Measurement Methods NIOSH 7400
Personal Protection & Sanitation Skin: Prevent skin contact Eyes: Prevent eye contact Wash skin: Daily Remove: No recommendation Change: Daily | First Aid (See procedures) Eye: Irrigate immediately Breathing: Fresh air
Respirator Recommendations NIOSH Up to 5X REL: (APF = 5) Any dust respirator Up to 10X REL: (APF = 10) Any dust respirator except single-use and quarter-mask respirators/(APF = 10) Any air-purifying respirator with a high-efficiency particulate filter/(APF = 10) Any supplied-air respirator Up to 25X REL: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode/(APF = 25) Any powered, air-purifying respirator with a dust filter Up to 50X REL: (APF = 50) Any air-purifying, full-facepiece respirator with a high-efficiency particulate filter/(APF = 50) Any powered, air-purifying respirator with a tight-fitting facepiece and a high-efficiency particulate filter/(APF = 50) Any self-contained breathing apparatus with a full facepiece/(APF = 50) Any supplied-air respirator with a full facepiece Up to 1000X REL: (APF = 2000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode Emergency or planned entry into unknown concentrations or IDLH conditions: (APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode/(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus Escape: (APF = 50) Any air-purifying, full-facepiece respirator with a high-efficiency particulate filter/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, skin and/or eye contact
Symptoms Irritation eyes, skin, nose, throat; dyspnea (breathing difficulty)
Target Organs Eyes, skin, respiratory system
See also: INTRODUCTION