# NIOSH Pocket Guide to Chemical Hazards
Chromium metal | CAS 7440-47-3
Cr | RTECS GB4200000
Synonyms & Trade Names Chrome, Chromium | DOT ID & Guide
Exposure Limits | NIOSH REL: TWA 0.5 mg/m3 See Appendix C
OSHA PEL*: TWA 1 mg/m3 See Appendix C [*Note: The PEL also applies to insoluble chromium salts.]
IDLH 250 mg/m3 (as Cr) | Conversion
Physical Description Blue-white to steel-gray, lustrous, brittle, hard, odorless solid.
MW: 52.0 | BP: 4788°F | MLT: 3452°F | Sol: Insoluble
VP: 0 mmHg (approx) | IP: NA |  | Sp.Gr: 7.14
Fl.P: NA | UEL: NA | LEL: NA |
Noncombustible Solid in bulk form, but finely divided dust burns rapidly if heated in a flame.
Incompatibilities & Reactivities Strong oxidizers (such as hydrogen peroxide), alkalis
Measurement Methods NIOSH 7024; OSHA ID121, ID125G
Personal Protection & Sanitation Skin: No recommendation Eyes: No recommendation Wash skin: No recommendation Remove: No recommendation Change: No recommendation | First Aid (See procedures) Eye: Irrigate immediately Skin: Soap wash Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH Up to 2.5 mg/m3: (APF = 5) Any dust and mist respirator* Up to 5 mg/m3: (APF = 10) Any dust and mist respirator except single-use and quarter-mask respirators*/(APF = 10) Any supplied-air respirator* Up to 12.5 mg/m3: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode*/(APF = 25) Any powered, air-purifying respirator with a dust and mist filter* Up to 25 mg/m3: (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 250 mg/m3: (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, ingestion, skin and/or eye contact
Symptoms Irritation eyes, skin; lung fibrosis (histologic)
Target Organs Eyes, skin, respiratory system
See also: INTRODUCTION