Ammonium chromate

  • Ammonium chromate(IV)
Formula
(NH4)2CrO4
Structure
Description
A yellow crystalline solid.
Uses
Sensitizing gelatin in photography, in textile printing pastes, in fixing chromate dyes on wool, as a reagent in analytical chemistry.

Registry Numbers and Inventories.
CAS
7788-98-9
EC (EINECS/ELINCS)
232-138-4
RTECS
GB2880000
RTECS class
Mutagen
UN (DOT)
9086
Merck
12,538
Beilstein/Gmelin
71655 (G)
Swiss Giftliste 1
G-1107
Canada DSL/NDSL
NDSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
CrH12N3O4
Formula mass
152.07
Melting point, °C
180.0
Density
1.8 g/cm3 (20 C)
Solubility in water
Soluble

Hazards and Protection.
Storage
Keep well closed.
Handling
All chemicals should be considered hazardous. Avoid direct physical contact. Use appropriate, approved safety equipment. Untrained individuals should not handle this chemical or its container. Handling should occur in a chemical fume hood.
Protection
Wear appropriate protective gloves, clothing and goggles.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
Keep material out of water sources and sewers. Build dikes to contain flow as necessary. Land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. Cover solids with a plastic sheet to prevent dissolving in rain or fire fighting water. Water spill: Add sodium bisulfite (NaHSO3). Neutralize with agricultural lime (CaO), crushed limestone (CaCO3), or sodium bicarbonate (NaHCO3). Adjust pH to neutral (pH=7). Use mechanical dredges or lifts to remove immobilized masses of pollutants and precipitates.
Stability
Slight. Reactive only under extreme conditions; can explode if heated or shocked.
Incompatibilities
Reacts with reducing materials, including large numbers of organic compounds.
Decomposition
When heated to decomposition it emits toxic fumes of ammonia and nitrogen oxides.

Fire.
Fire fighting
Extinguish fire using agent suitable for type of surrounding fire. (Material itself does not burn or burns with difficulty.)
Fire potential
Non-combustible
Hazards
May ignite combustibles (wood, paper, oil, clothing, etc.). Some will react explosively with hydrocarbons (fuels).
Combustion products
Decomposes producing toxic combustion products.
 
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
Increases in blood pressure and pulse have been reported. An altered mental status (coma) may be seen, but is not characteristic unless hypoxemia occurs. Seizures may occur with extensive absorption. No data were available to assess the teratogenic potential of this agent. <br>Decreased egg production has occurred in experimental animals. Ammonia crosses the ovine placental barrier. <br>No data were available to assess the potential effects of exposure to this agent during lactation. <br>No information about possible male reproductive effects was found in available references.
   Ingestion
Nausea and vomiting occur frequently following ingestion. Swelling of the lips, mouth, and larynx, and oral or esophageal burns may occur if concentrated ammonia solutions are ingested.
   Inhalation
May cause severe injury, burns, or death.
   Skin
Concentrated ammonia may produce liquifaction necrosis and deep penetrating burns.
   Eyes
Oral burns and severe corneal injury may result from acute exposure. Chronic inhalation produces deep perforating nasal ulcers (chrome holes).

First aid
 
   Ingestion
Seek medical assistance.
   Inhalation
Move to fresh air.
   Skin
Wash with soap and water.
   Eyes
Immediately flush skin or eyes with running water for at least 20 minutes.

Transport.
UN number
9086
Response guide
Hazard class
5.1
USCG CHRIS Code
ACH
 
Std. Transport #
4963302