Chromium

  • Chrome
Formula
Cr
Structure
Description
Steel-grey, lustrous metal, odorless, available as lumps, granules, powder or high purity single crystals.
Uses
Incr resistance & durability of metals, chromeplating other metals.

Registry Numbers and Inventories.
CAS
7440-47-3
EC (EINECS/ELINCS)
231-157-5
RTECS
GB4200000
RTECS class
Tumorigen; Mutagen
UN (DOT)
3089
Merck
12,2288
Beilstein/Gmelin
16274 (G)
RCRA
D007
Swiss Giftliste 1
G-6529
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Korea ECL
Listed

Properties.
Formula
Cr
Formula mass
51.996
Melting point, °C
1840
Boiling point, °C
2469
Vapor density (air=1)
7.14
Density
7.2 g/cm3 (20 C)
Solubility in water
Insoluble
Heat of fusion
679.0 kJ/mol
Heat of vaporization
298.8 kJ/mol

Hazards and Protection.
Storage
Keep away from heat, sparks, and flame. Store in a tightly closed container. Keep from contact with oxidizing materials. Store in a cool, dry, well-ventilated area away from incompatible substances. Keep away from acids. Keep containers tightly closed. Do not expose to air. Store under an inert atmosphere.
Insufficient information
Handling
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Use with adequate ventilation. Minimize dust generation and accumulation. Use spark-proof tools and explosion proof equipment. Avoid contact with skin and eyes. Keep container tightly closed. Avoid contact with heat, sparks and flame. Avoid ingestion and inhalation. Handle under an inert atmosphere.
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 appropriate gloves to prevent skin exposure. Clothing: Wear appropriate protective clothing 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
Clean up spills immediately, using the appropriate protective equipment. Sweep up or absorb material, then place into a suitable clean, dry, closed container for disposal. Avoid generating dusty conditions. Remove all sources of ignition. Isolate area and deny entry. Place under an inert atmosphere. Do not use combustible materials such as paper towels to clean up spill.
Stability
Stable under normal temperatures and pressures. Powder or liquid is pyrophoric.
Incompatibilities
Ammonium nitrate, hydrogen peroxide, lithium, nitric oxiode, potassium chlorate, sulfuri dioxide, strong oxidizers, hydrochloric acid, sulfuric acid, nitrogen oxide,
Decomposition
Toxic chromium oxide fumes.

Fire.
Autoignition, °C
400
Fire fighting
DO NOT USE WATER, FOAM OR carbon dioxide. Dousing metallic fires with water may generate hydrogen gas, an extremely dangerous explosion hazard, particularly if fire is in a confined environment. Use DRY sand, graphite powder, dry sodium chloride based extinguishers, G-1 or Met-L-X powder. Confining and smothering metal fires is preferable rather than applying water.
Fire potential
Moderately flammable. Combustion with moderate heating.
Hazards
Oxides from metallic fires are a severe health hazard. Fire may produce irritating, corrosive and/or toxic gases.
Health
2
 
Flammability
1
 
 
Reactivity
1
 

Health.
Exposure limit(s)
OSHA PEL: TWA 1 mg/m3 See Appendix C *Note: The PEL also applies to insoluble chromium salts. NIOSH REL: TWA 0.5 mg/m3 See Appendix C NIOSH IDLH: 250 mg/m3 (as Cr)
Poison_Class
-
Exposure effects
Prolonged inhalation may cause respiratory tract inflammation and lung damage.
   Ingestion
May cause irritation of the digestive tract. May cause liver damage.
   Inhalation
Causes respiratory tract irritation. Inhalation of fumes may cause metal fume fever, which is characterized by flu-like symptoms with metallic taste, fever, chills, cough, weakness, chest pain, muscle pain and increased white blood cell count. May cause asthma and shortness of breath. May cause headache, coughing, fever, weight loss, and pneumoconiosis.
   Skin
Causes skin irritation. Prolonged and/or repeated contact may cause irritation and/or dermatitis. May cause skin sensitization, an allergic reaction, which becomes evident upon re-exposure to this material.
   Eyes
Causes eye irritation. May cause conjunctivitis.

First aid
 
   Ingestion
Do NOT induce vomiting. 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
Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical aid. DO NOT use mouth-to-mouth respiration.
   Skin
Flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Get medical aid if irritation develops or persists. Wash clothing before reuse.
   Eyes
Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately.

Transport.
UN number
3089
Response guide
Hazard class
4.1
Packing Group
II; III
 
USCG CHRIS Code
CRR
 
HS Code
8112 29 00