Chromium trioxide

  • Chromium oxide
  • Chromia
  • Chromic anhydride
  • Chromic trioxide
  • Chromic acid
Formula
CrO3
Structure
Description
Dark red, bipyramidal prismatic crystals, flakes or granular powder, odorless, delinquescent.
Uses
Medication (vet).

Registry Numbers and Inventories.
CAS
1333-82-0
EC (EINECS/ELINCS)
215-607-8
EC Index Number
024-001-00-0
EC Class
Oxidising; Carcinogenic Category 1; Toxic; Corrosive; Sensitising; Dangerous for the Environment
R 49 8 25 35 43 50/53
S 53 45 60 61
RTECS
GB6650000
RTECS class
Tumorigen; Mutagen; Reproductive Effector; Human Data
UN (DOT)
1463
Merck
13,2256
Beilstein/Gmelin
15491 (G)
RCRA
D007
Swiss Giftliste 1
G-1434
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
CrO3
Formula mass
99.99
Vapor density (air=1)
3.4
Odor Threshold Odor threshold Odorless
Solubility in water
Very soluble
Thermal expansion
0.00017/K
Heat of fusion
15.8 kJ/mol

Hazards and Protection.
Storage
Do not store near combustible materials. Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances. Corrosives area.
Handling
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Avoid contact with skin and eyes. Keep container tightly closed. Avoid contact with clothing and other combustible materials. Avoid ingestion and inhalation. Use with adequate ventilation. Discard contaminated shoes.
Protection
Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear a chemical apron. Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear a chemical apron. Wear appropriate protective gloves to prevent skin exposure.
Respirators
Follow the OSHA respirator regulations found in 29CFR 1910.134 or European Standard EN 149. Always use a NIOSH or European Standard EN 149 approved respirator when necessary.
Small spills/leaks
Sweep up or absorb material, then place into a suitable clean, dry, closed container for disposal. Avoid generating dusty conditions. Provide ventilation. Do not use combustible materials such as paper towels to clean up spill.
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Acetic Acid, acetic anhydride, acetone, alcohols, alkali metals, ammonia, arsenic, anthracene, benzene, bromine pentafluorine, butyric acid, camphor, chlorine trifluoride, chromous sulfide, diethyl ether, dimethyl formamide, glycerol, hydrogen sulfide, methyl alcohol, naphthalene,peroxyformic acid, phosphorus, potassium hexacyanoferrate, pyridine, selenium, sodium, sulfur, turpentine, ethyl alcohol and many hydrocarbons.
Decomposition
Irritating and toxic fumes and gases, chromium dioxide.

Fire.
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Strong oxidizer. Contact with combustible materials may cause a fire. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Use water spray to keep fire-exposed containers cool. Wear appropriate protective clothing to prevent contact with skin and eyes. Wear a self-contained breathing apparatus (SCBA) to prevent contact with thermal decomposition products. Containers may explode in the heat of a fire. Extinguishing media: Use water only! Use extinguishing media most appropriate for the surrounding fire. Cool containers with flooding quantities of water until well after fire is out. DO NOT use dry chemicals, carbon dioxide, Halon or foams.
Fire potential
These substances will accelerate burning when involved in a fire.
Hazards
May explode from heat or contamination. Some may burn rapidly. Some will react explosively with hydrocarbons (fuels). May ignite combustibles (wood, paper, oil, clothing, etc.). Containers may explode when heated. Runoff may create fire or explosion hazard.
Combustion products
Fire may produce irritating, corrosive and/or toxic gases.
Health
3
 
Flammability
1
 
 
Reactivity
1
 
 
Special
O

Health.
Exposure limit(s)
TLV (as Cr) - 0.05 mg/m3 (ACGIH 1993-1994)
Carcinogin
G-A1, I-1, N-1, CP65
Poison_Class
1*
Exposure effects
Prolonged or repeated inhalation may cause nosebleeds, nasal congestion, erosion of the teeth, perforation of the nasal septum, chest pain and bronchitis. Prolonged or repeated eye contact may cause conjunctivitis. Prolonged or repeated skin contact may cause sensitization dermatitis and possible destruction and/or ulceration. Chronic ingestion may cause effects similar to those of acute ingestion. Chronic exposure to water insoluble hexavalent chromium compounds has been shown to be associated with lung cancer and gastrointestinal tract tumors.
   Ingestion
Harmful if swallowed. May cause severe gastrointestinal tract irritation with nausea, vomiting and possible burns. May cause liver and kidney damage.
   Inhalation
May cause irritation of the respiratory tract with burning pain in the nose and throat, coughing, wheezing, shortness of breath and pulmonary edema. May cause asthmatic attacks due to allergic sensitization of the respiratory tract.
   Skin
May cause skin sensitization, an allergic reaction, which becomes evident upon re-exposure to this material. May cause irritation with burning pain, itching and redness. May cause deep, penetrating ulcers of the skin. May be absorbed through damaged or abraded skin in harmful amounts. Chronic exposure to water insoluble hexavalent chromium compounds has been shown to be associated with lung cancer and gastrointestinal tract tumors.
   Eyes
May cause irreversible eye injury. Contact with eyes may cause severe irritation, and possible eye burns.

First aid
 
   Ingestion
If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Get medical aid immediately.
   Inhalation
Get medical aid immediately. Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. DO NOT use mouth-to-mouth respiration.
   Skin
Get medical aid. Wash clothing before reuse. Rinse area with large amounts of water for at least 15 minutes. Destroy contaminated shoes.
   Eyes
Get medical aid immediately. Extensive irrigation is required (at least 30 minutes).

Transport.
UN number
1463
Response guide
Hazard class
5.1
Packing Group
II
 
USCG CHRIS Code
CMA
 
HS Code
2819 10 00
 
Std. Transport #
4918510