Agent Name

Chromic acid and chromates

CAS Number

7738-94-5; varies

Formula

Cr-O3, varies

Major Category

Metals

Synonyms

Chromic acid (CrO3): Chromic anhydride, Chromic oxide, Chromium(VI) oxide (1:3), Chromium trioxide; Synonyms of chromates (i.e., chromium(VI) compounds) such as zinc chromate vary depending upon the specific compound; [NIOSH] UN1463

Category

Chromium Compounds, Inorganic

Description

CrO3: Dark-red, odorless flakes or powder. [Note: Often used in an aqueous solution (H2CrO4); [NIOSH]

Sources/Uses

Used in electroplating, metal cleaning, leather tanning, and photography; [HSDB]

Comments

Classified as a water-soluble, hexavalent chromium compound; [ACGIH] Chronic exposure to hexavalent chromium may produce evidence of kidney and liver injury. [ATSDR Case Studies # 4] Can cause second and third degree burns on short contact; [CHRIS] Highly corrosive to skin; [Quick CPC] Occupational asthma documented in a cement floor worker, plater, and other workers exposed to chromate salt; [Malo] Epidemiological studies of chromate production workers showed increased lung cancer. [IARC] See "Chromium" and linked occupational diseases.

Exposure Assessment
Skin Designation (ACGIH)

Insufficient data

Bioaccumulates

Yes

TLV (ACGIH)

0.05 mg/m3, as Cr

PEL (OSHA)

Ceiling(OSHA) = 0.1 mg/m3, as CrO3

IDLH (NIOSH)

15 mg/m3, as Cr(VI)

Excerpts from Documentation for IDLHs

Human data: A worker exposed for several days to concentrations of chromic acid mist of about 20 to 30 mg/m3 (equivalent to about 10 to 15 mg Cr(VI)/m3) experienced cough, headache, dyspnea, and substernal pain; the signs persisted for 2 weeks [ILO 1971]. Another man working on the same process was similarly but less severely affected [ILO 1971].

Explanatory Notes

The Guide from the Emergency Response Guidebook is for "chromic acid, solution."

Reference Link

ICSC: Chromium(VI) oxide

Adverse Effects
Nephrotoxin

Yes

Skin Sensitizer

Yes

Asthma

Yes

Hepatotoxin

Hepatotoxin, Secondary

Dermatotoxin

Skin Burns

IARC Carcinogen

Known Carcinogen

NTP Carcinogen

Human Carcinogen

ACGIH Carcinogen

Confirmed Human

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information

Search TOXNET

Chemical Information

Search ChemIDplus

Biomedical References

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Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent:

Processes

Industrial Processes with risk of exposure:

Activities

Activities with risk of exposure: