Ammonium dichromate

  • Ammonium bichromate
  • Ammonium dichromate(VI)
  • Chromic acid, diammonium salt
Formula
(NH4)2Cr2O7
Structure
Description
Ammonium dichromate is a bright orange red crystalline solid.
Uses
Source of pure nitrogen, catalyst, dye mordant, pickling agent.

Registry Numbers and Inventories.
CAS
7789-09-5
EC (EINECS/ELINCS)
232-143-1
EC Index Number
024-003-00-1
EC Class
Explosive; Explosive when dry; Oxidising; Carcinogenic Category 2; Mutagenic Category 2; Very toxic; Toxic; Harmful; Irritant; Sensitising; Dangerous for the Environment
R 49 46 1 8 E21 E25 E26 37/38 41 43 50/53
S 53 45 60 61
RTECS
HX7650000
RTECS class
Tumorigen; Mutagen; Human Data
UN (DOT)
1439
Merck
12,544
Beilstein/Gmelin
21618 (G)
EPA OPP
68305
Swiss Giftliste 1
G-1102
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
Cr2H8N2O7
Formula mass
252.07
Melting point, °C
180
Density
2.15 g/cm3 (20 C)
Solubility in water
36 g/100 mL
Dielectric constant
8,28 (25 C)

Hazards and Protection.
Storage
Keep away from heat, sparks, and flame. Keep away from sources of ignition. Do not store near combustible materials. Keep container closed when not in use. Store in a cool, dry, well-ventilated area away from incompatible substances. Keep away from acids. Keep away from reducing agents.
Handling
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Use only in a well ventilated area. Minimize dust generation and accumulation. Do not get in eyes, on skin, or on clothing. Empty containers retain product residue, (liquid and/or vapor), and can be dangerous. Keep container tightly closed. Do not ingest or inhale. Do not store near combustible materials. Discard contaminated shoes. Do not pressurize, cut, weld, braze, solder, drill, grind, or expose empty containers to heat, sparks or open flames.
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. Clean up spills immediately, using the appropriate protective equipment. Avoid generating dusty conditions. Remove all sources of ignition. Wet area to prevent drying out. Provide ventilation. Do not use combustible materials such as paper towels to clean up spill. Keep combustibles (wood, paper, oil, etc.,) away from spilled material.
Disposal code
15
Stability
Stable under normal shipping and handling conditions. However, may decompose if heated.
Incompatibilities
Reducing agents, carbides, hydrazine, combustible organics, wood, sulfur, aluminum, plastics, potassium chlorates, sodium nitrate.
Decomposition
Oxides of nitrogen, irritating and toxic fumes and gases, toxic chromium oxide fumes.

Fire.
Autoignition, °C
218
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 with caution and in flooding amounts. This material poses an explosion hazard when dry. Extinguishing media: Use water only! Contact professional fire-fighters immediately. Cool containers with flooding quantities of water until well after fire is out. For large fires, flood fire area with water from a distance. DO NOT use dry chemicals, carbon dioxide, Halon or foams.
Fire potential
Moderately flammable. Will ignite if exposed to open flame or sparks moderate hazard.
Hazards
May explode from heat or contamination.
Combustion products
Greenish chromic oxide smoke may cause irritation of lungs and mucous membranes.
Health
2
 
Flammability
1
 
 
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 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. May cause cancer according to animal studies. Effects may be delayed. Laboratory experiments have resulted in mutagenic effects.
   Ingestion
Harmful if swallowed. May cause severe and permanent damage to the digestive tract. Causes gastrointestinal tract burns. May cause circulatory system failure. May cause perforation of the digestive tract. Methemoglobinemia is characterized by dizziness, drowsiness, headache, breath shortness, cyanosis with bluish skin, rapid heart rate and chocolate-brown colored blood. May cause hemolysis. May cause nausea, vomiting, and diarrhea, possibly with blood.
   Inhalation
Causes severe irritation of upper respiratory tract with coughing, burns, breathing difficulty, and possible coma. 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. May cause systemic effects.
   Skin
Causes skin burns. May cause skin sensitization, an allergic reaction, which becomes evident upon re-exposure to this material. May cause deep, penetrating ulcers of the skin. May be absorbed through the skin.
   Eyes
Causes eye burns. May cause permanent corneal opacification.

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
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. Extensive irrigation is required (at least 30 minutes).

Transport.
UN number
1439
Response guide
Hazard class
5.1
Packing Group
II
 
USCG CHRIS Code
AMD
 
HS Code
2841 50 00
 
Std. Transport #
4918330