Potassium dichromate

  • Potassium bichromate
Formula
K2Cr2O7
Structure
Description
Bright, yellowish-red, transparent crystals, odorless.
Uses
Tanning leather, dyeing, painting, printing, decorating porcelain, photolithography, pigment-prints, bleaching palm oil, wax & sponges, waterproofing fabrics, oxidizer in manufacture organic chemicals, corrosion inhibitor, depolarizer for dry cells, in electric batteries, pharmaceutic aid, oxidizing agent.

Registry Numbers and Inventories.
CAS
7778-50-9
EC (EINECS/ELINCS)
231-906-6
EC Index Number
024-002-00-6
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
HX7680000
RTECS class
Tumorigen; Mutagen; Reproductive Effector; Human Data
UN (DOT)
1479
Merck
12,7790
Beilstein/Gmelin
15021 (G)
EPA OPP
68302
Swiss Giftliste 1
G-1744
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
Cr2K2O7
Formula mass
294.19
Melting point, °C
398
Vapor density (air=1)
10
Odor Threshold Odor threshold Odorless
Density
2.67 g/cm3
Solubility in water
190 g/L
Heat of fusion
36.6 kJ/mol

Hazards and Protection.
Storage
Keep away from heat, sparks, and flame. Keep away from sources of ignition. Do not store near combustible materials. Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances. Keep away from reducing agents.
Handling
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Minimize dust generation and accumulation. Do not get in eyes, on skin, or on clothing. Keep container tightly closed. Avoid contact with heat, sparks and flame. Avoid contact with clothing and other combustible materials. Do not ingest or inhale. Use only in a chemical fume hood. 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 appropriate protective gloves to prevent skin exposure. Clothing: Wear appropriate protective 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. Avoid runoff into storm sewers and ditches which lead to waterways. Clean up spills immediately, using the appropriate protective equipment. Avoid generating dusty conditions. Remove all sources of ignition. Provide ventilation. Do not use combustible materials such as paper towels to clean up spill.
Disposal code
22
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Reducing agents, acids, organic matter, hydrazine, sulfuric acid + acetone, hydroxylamine, ethylene glycol, boron, silicon, iron, tungsten, sulfur, aluminum, plastics.
Decomposition
Irritating and toxic fumes and gases, oxides of potassium, chromium dioxide, potassium.

Fire.
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Water runoff can cause environmental damage. Dike and collect water used to fight fire. 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. Use water with caution and in flooding amounts. Containers may explode if exposed to fire. Extinguishing media: Use water only! Do NOT use dry chemical. Do NOT use halocarbons and sodium bicarbonate. Do NOT use carbon dioxide or dry chemical. Contact professional fire-fighters immediately. Cool containers with flooding quantities of water until well after fire is out.
Fire potential
Nonflammable. Moderate by chemical reaction. Powerful oxidizer.
Hazards
May decompose, generating oxygen. Supports the combustion of other materials.
Combustion products
Fire may produce irritating, corrosive and/or toxic gases.
Health
4
 
Flammability
0
 
 
Reactivity
1
 
 
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
1*
Exposure effects
Prolonged or repeated skin contact may cause sensitization dermatitis and possible destruction and/or ulceration. May cause respiratory tract cancer. May cause liver and kidney damage. Chronic inhalation may cause nasal septum ulceration and perforation. May cause reproductive and fetal effects. Effects may be delayed. Laboratory experiments have resulted in mutagenic effects. Repeated or prolonged exposure may cause erosion and discoloration of the teeth.
   Ingestion
May be fatal if swallowed. May cause severe and permanent damage to the digestive tract. Causes gastrointestinal tract burns. May cause perforation of the digestive tract. May cause methemoglobinemia, cyanosis, convulsions, and death. Methemoglobinemia is characterized by dizziness, drowsiness, headache, breath shortness, cyanosis with bluish skin, rapid heart rate and chocolate-brown colored blood.
   Inhalation
May cause asthmatic attacks due to allergic sensitization of the respiratory tract. May cause ulceration and perforation of the nasal septum if inhaled in excessive quantities. Causes chemical burns to the respiratory tract. Aspiration may lead to pulmonary edema.
   Skin
May be fatal if absorbed through the skin. Causes skin burns. May cause skin sensitization, an allergic reaction, which becomes evident upon re-exposure to this material. Chrome ulcers , penetrating lesions of the skin, occur chiefly on the hand and forearms where there has been a break in the epidermis.
   Eyes
Causes eye burns. May cause chemical conjunctivitis and corneal damage.

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
Get medical aid immediately. Remove from exposure to fresh air immediately. If breathing is difficult, give oxygen. DO NOT use mouth-to-mouth respiration. If breathing has ceased apply artificial respiration using oxygen and a suitable mechanical device such as a bag and a mask.
   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. Destroy contaminated shoes.
   Eyes
Get medical aid immediately. Do NOT allow victim to rub or keep eyes closed. Extensive irrigation is required (at least 30 minutes).

Transport.
UN number
1479
Response guide
Hazard class
5.1
Packing Group
I; II; III
 
USCG CHRIS Code
PTD
 
HS Code
2841 50 00
 
Std. Transport #
4925234