Chromic acid and chromates
Synonyms & Trade Names
Chromic acid (CrO3), Chromic anhydride, Chromic oxide, Chromium(VI) oxide (1:3), Chromium trioxide, Zinc chromateCAS No.
1333-82-0 (CrO3)RTECS No.
GB6650000 (CrO3)Exposure Limits
NIOSH REL
(as Cr): Ca TWA 0.0002 mg/m3 (8-hours) See Appendix A See Appendix COSHA PEL
(as CrO3): TWA 0.005 mg/m3 See Appendix CPhysical Description
CrO3: Dark-red, odorless flakes or powder. [Note: Often used in an aqueous solution (H2CrO4).]Molecular Weight
100.0Boiling Point
482°F (Decomposes)Melting Point
387°F (Decomposes)Solubility
63%Vapor Pressure
Very lowIonization Potential
NASpecific Gravity
2.70 (CrO3)Flash Point
NAUpper Exposive Limit
NALower Explosive Limit
NA
CrO3: Noncombustible Solid, but will accelerate the burning of combustible materials.
Incompatibilities & Reactivities
Combustible, organic, or other readily oxidizable materials (paper, wood, sulfur, aluminum, plastics, etc.); corrosive to metalsExposure Routes
inhalation, ingestion, skin and/or eye contactSymptoms
irritation respiratory system; nasal septum perforation; liver, kidney damage; leukocytosis (increased blood leukocytes), leukopenia (reduced blood leukocytes), eosinophilia; eye injury, conjunctivitis; skin ulcer, sensitization dermatitis; [potential occupational carcinogen]Target Organs
Blood, respiratory system, liver, kidneys, eyes, skinCancer Site
[lung cancer]Personal Protection/Sanitation
(See protection codes)Skin:Prevent skin contact
Eyes:Prevent eye contact
Wash skin:When contaminated
Remove:When wet or contaminated
Change:Daily
Provide:Eyewash, Quick drench
First Aid
(See procedures)Eye:Irrigate immediately
Skin:Soap flush immediately
Breathing:Respiratory support
Swallow:Medical attention immediately
Respirator Recommendations
NIOSH
At concentrations above the NIOSH REL, or where there is no REL, at any detectable concentration:
(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 an N100, R100, or P100 filter.
Click here for information on selection of N, R, or P filters.
Any appropriate escape-type, self-contained breathing apparatus
- Page last reviewed:April 11, 2016
- Page last updated:April 11, 2016
- Content source:
- National Institute for Occupational Safety and Health (NIOSH) Education and Information Division