Print
Chemical Datasheet

SODIUM DICHROMATE

5.1 - Oxidizer 6.1 - Poison

Chemical Identifiers

CAS Number UN/NA Number DOT Hazard Label USCG CHRIS Code
  • 10588-01-9   (anhydrous)
  • 7789-12-0   (dihydrate)
  • 3087
  • Oxidizer
  • Poison
  • SCR
NIOSH Pocket Guide International Chem Safety Card
Chromic acid and chromates
  • SODIUM DICHROMATE (ANHYDROUS)
NFPA 704
data unavailable
General Description
A red or red-orange crystalline solid. May be strongly irritating to skin, eyes and mucous membranes. Used as a corrosion inhibitor, and in the manufacture of other chemicals.

Hazards

Reactivity Alerts
Air & Water Reactions
Deliquescent. Soluble in water.
Fire Hazard
Behavior in Fire: Decomposes to produce oxygen when heated. May ignite other combustibles upon contact. (USCG, 1999)
Health Hazard
Inhalation of dust or mist causes respiratory irritation sometimes resembling asthma; nasal septal perforation may occur. Ingestion causes vomiting, diarrhea, and (rarely) stomach and kidney complications. Contact with eyes or skin produces local irritation; repeated skin exposure causes dermatitis. (USCG, 1999)
Reactivity Profile
SODIUM DICHROMATE is a strong oxidizing agent. Incompatible with strong acids. (NTP, 1992). Contact with combustible materials may lead to fires. Toxic chromium oxide fumes may form in fire (USCG, 1999). The well known "chromic acid mixture" of dichromate and sulfuric acid with organic residue led to violent exothermic reaction. This mixture in combination with acetone residue also led to violent reaction. The combination of the dichromate and sulfuric acid with alcohols, ethanol and 2-propanol, led to violent exothermic reaction. Because of the occurrence of many incidents involving the dichromate-sulfuric acid mix with oxidizable organic materials, it is probably best to avoid such interactions. The combination of the dichromate with hydrazine is explosive (one may expect the reaction of the dichromate to be vigorous with amines in general), [Mellor, 1943, Vol. 11, 234]. The addition of the dehydrated dichromate salt to acetic anhydride led to an exothermic reaction which eventually exploded. An induction period proceeded the explosion event [Bretherick, 5th Ed., 1995]. Boron, silicon, and dichromates form pyrotechnic mixtures. A mixture of acetic acid, 2-methyl-2-pentenal and the dichromate led to a runaway reaction and eruption of the reactor contents, [J. Haz. Mat., 1987, 233-239].
Belongs to the Following Reactive Group(s)
Potentially Incompatible Absorbents

Use caution: Liquids with this reactive group classification have been known to react with the absorbents listed below.

Response Recommendations

Isolation and Evacuation
Excerpt from 141 Polymerizable warning [Oxidizers - Toxic]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

LARGE SPILL: Consider initial downwind evacuation for at least 100 meters (330 feet).

FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2020)
Firefighting
Excerpt from 141 Polymerizable warning [Oxidizers - Toxic]:

SMALL FIRE: Use water. Do not use dry chemicals or foams. CO2 or Halon® may provide limited control.

LARGE FIRE: Flood fire area with water from a distance. Do not move cargo or vehicle if cargo has been exposed to heat. If it can be done safely, move undamaged containers away from the area around the fire.

FIRE INVOLVING TANKS OR CAR/TRAILER LOADS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. ALWAYS stay away from tanks engulfed in fire. For massive fire, use unmanned master stream devices or monitor nozzles; if this is impossible, withdraw from area and let fire burn. (ERG, 2020)
Non-Fire Response
Excerpt from 141 Polymerizable warning [Oxidizers - Toxic]:

Keep combustibles (wood, paper, oil, etc.) away from spilled material. Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk.

SMALL DRY SPILL: With clean shovel, place material into clean, dry container and cover loosely; move containers from spill area.

LARGE SPILL: Dike far ahead of spill for later disposal. (ERG, 2020)
Protective Clothing
Approved dust mask; protective gloves; goggles or face shield. (USCG, 1999)
DuPont Tychem® Suit Fabrics
No information available.
First Aid
INGESTION: have victim drink water or milk; do NOT induce vomiting; call a doctor.

SKIN OR EYE CONTACT: treat like acid burns; flush eyes with water for at least 15 min.; external lesions can be scrubbed with a 2% solution of sodium thiosulfate. (USCG, 1999)

Physical Properties

Chemical Formula:
  • Na2Cr2O7
Flash Point: data unavailable
Lower Explosive Limit (LEL): data unavailable
Upper Explosive Limit (UEL): data unavailable
Autoignition Temperature: Not flammable (USCG, 1999)
Melting Point: 675°F (USCG, 1999)
Vapor Pressure: data unavailable
Vapor Density (Relative to Air): data unavailable
Specific Gravity: 2.35 at 77°F (USCG, 1999) - Denser than water; will sink
Boiling Point: data unavailable
Molecular Weight: 262.01 (USCG, 1999)
Water Solubility: data unavailable
Ionization Energy/Potential: data unavailable
IDLH: 15 mg Cr(VI)/m3 ; A potential occupational carcinogen. (NIOSH, 2023)

AEGLs (Acute Exposure Guideline Levels)

No AEGL information available.

ERPGs (Emergency Response Planning Guidelines)

No ERPG information available.

PACs (Protective Action Criteria)

Chemical PAC-1 PAC-2 PAC-3
Sodium dichromate; (Disodium dichromate) (10588-01-9) 0.38 mg/m3 6.5 mg/m3 39 mg/m3
Sodium dichromate dihydrate (7789-12-0) 0.43 mg/m3 7.5 mg/m3 45 mg/m3
(DOE, 2018)

Regulatory Information

EPA Consolidated List of Lists

Regulatory Name CAS Number/
313 Category Code
EPCRA 302
EHS TPQ
EPCRA 304
EHS RQ
CERCLA RQ EPCRA 313
TRI
RCRA
Code
CAA 112(r)
RMP TQ
Chromium Compounds N090 & 313
Sodium bichromate 10588-01-9 10 pounds 313c

(EPA List of Lists, 2022)

CISA Chemical Facility Anti-Terrorism Standards (CFATS)

No regulatory information available.

OSHA Process Safety Management (PSM) Standard List

No regulatory information available.

Alternate Chemical Names