Sodium dichromate dihydrate

  • Sodium bichromate dihydrate
Formula
Na2Cr2O7.2H2O
Structure
Description
Bright orange-yellow crystal or powder.
Uses
Oxidizing agent in manufacture of dyes, many other synthetic organic chemicals, inks etc.; in chrome-tanning of hides; in electric batteries; bleaching fats, oils, sponges, resins; refining petroleum; manufacture chromic acid, other chromates and chrome pigments; in corrosion inhibitors, corrosion-inhibiting paints; in many metal treatments; electroengraving of copper; mordant in dyeing.

Registry Numbers and Inventories.
CAS
7789-12-0
EC (EINECS/ELINCS)
234-190-3
EC Index Number
024-004-01-4
EC Class
Carcinogenic Category 2; Mutagenic Category 2; Very toxic; Toxic; Harmful; Irritant; Sensitising; Dangerous for the Environment
R 49 46 21 25 26 37/38 41 43 50/53
S 53 45 60 61
RTECS
HX7750000
RTECS class
Tumorigen; Mutagen
UN (DOT)
1479
Merck
12,8754
Beilstein/Gmelin
34318 (G)
EPA OPP
68306
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed

Properties.
Formula
Cr2Na2O7 . 2 H2O
Formula mass
298.00
Melting point, °C
356.7
Vapor density (air=1)
10.3
Density
2.35 g/cm3 (13 C)
Solubility in water
234 g/L (25 C)
Refractive index
1.661 (17 C)

Hazards and Protection.
Storage
Keep away from heat, sparks, and flame. Do not store near combustible materials. Store in a cool, dry, well-ventilated area away from incompatible substances.
Handling
Wash thoroughly after handling. Use with adequate ventilation. Minimize dust generation and accumulation. Do not get in eyes, on skin, or on clothing. Avoid contact with clothing and other combustible materials. Avoid ingestion and inhalation.
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 a chemical apron. Wear appropriate clothing to prevent skin exposure.
Respirators
A respiratory protection program that meets OSHA's 29 CFR 1910.134 and ANSI Z88.2 requirements or European Standard EN 149 must be followed whenever workplace conditions warrant a respirator's use.
Small spills/leaks
Vacuum or sweep up material and place into a suitable disposal container. Do not flush into a sewer. Clean up spills immediately, using the appropriate protective equipment. Avoid generating dusty conditions. Remove all sources of ignition.
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Reducing agents.
Decomposition
Carbon monoxide, irritating and toxic fumes and gases, carbon dioxide, sodium oxide, chromium dioxide.

Fire.
Flash Point,°C
400
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. 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. Use water with caution and in flooding amounts. Extinguishing media: Use water only! Contact professional fire-fighters immediately.
Fire potential
These substances will accelerate burning when involved in a fire.
Hazards
Strong oxidizer. Contact with combustible materials may cause a fire.
Combustion products
Fire may produce irritating, corrosive and/or toxic gases.
Health
2
 
Flammability
1
 
 
Reactivity
2
 
 
Special
O

Health.
Exposure limit(s)
TLV: 0.025 ppm; 0.16 mg/m3 (ACGIH 1991-1992). NIOSH REL: Ca 0.001 mg Cr(VI)/m3 See Appendix A See Appendix C NIOSH IDLH: Potential occupational carcinogen
Carcinogin
G-A1, I-1, N-1, CP65
Poison_Class
3 (Strong toxins)
Exposure effects
Prolonged or repeated skin contact may cause dermatitis. Prolonged or repeated exposure may lead to asthma and perforation of the nasal septum.
   Ingestion
Harmful if swallowed. Causes gastrointestinal tract burns. May cause kidney damage.
   Inhalation
Causes respiratory tract irritation. May cause ulceration and perforation of the nasal septum if inhaled in excessive quantities.
   Skin
Causes skin burns. May cause skin sensitization, an allergic reaction, which becomes evident upon re-exposure to this material. May be harmful if absorbed through the skin.
   Eyes
Contact with eyes may cause severe irritation, and possible eye burns.

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
Get medical aid immediately. Immediately flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse.
   Eyes
Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately. Do NOT allow victim to rub or keep eyes closed.

Transport.
UN number
1479
Response guide
Hazard class
5.1
Packing Group
I; II; III
 
USCG CHRIS Code
ZBC
 
HS Code
2841 30 00