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SECTION 1. CHEMICAL IDENTIFICATION

CHEMINFO Record Number: 640
CCOHS Chemical Name: Sodium oxalate

Synonyms:
Ethanedioic acid, disodium salt
Oxalic acid, disodium salt
Disodium oxalate

Chemical Name French: Oxalate de sodium
CAS Registry Number: 62-76-0
RTECS Number(s): KI1750000
Chemical Family: Saturated aliphatic carboxylic acid salt / saturated aliphatic dicarboxylic acid salt / alkanedioic acid / oxalate / disodium salt
Molecular Formula: C2-Na2-O4
Structural Formula: Na.O-C(=O)-C(=O)-O.Na

SECTION 2. DESCRIPTION

Appearance and Odour:
White, odourless, crystalline powder (6); hygroscopic (absorbs moisture from the air) (8).

Odour Threshold:
Odourless.(6)

Warning Properties:
POOR - sodium oxalate is odourless.

Composition/Purity:
Sodium oxalate is available commercially in grades with purity of 99% and greater. It is also available as a 0.1N standard volumetric solution. Sodium oxalate is one of the soluble salts of oxalic acid. It has many similarities (properties and hazards) to other oxalates. This record contains specific information available for sodium oxalate, supplemented with general information on oxalic acid and oxalate salts that is applicable to sodium oxalate.

Uses and Occurrences:
Sodium oxalate is used in textile finishing; tanning and finishing leather; blue printing; production of super white pulp; pyrotechnics; as a titrimetric standard substance; and for standardizing potassium permanganate solutions.(6,7,12)


SECTION 3. HAZARDS IDENTIFICATION

EMERGENCY OVERVIEW:
White, odourless, crystalline powder. Hygroscopic. Does not form a vapour at room temperature, but can probably burn if heated to decomposition. May be harmful if swallowed. May cause kidney damage. Inhalation of dusts or mists can cause irritation of the nose, throat and upper respiratory tract. EYE IRRITANT. Causes severe eye irritation. May cause skin irritation.



POTENTIAL HEALTH EFFECTS

Effects of Short-Term (Acute) Exposure

Inhalation:
Sodium oxalate is a solid that does not form a vapour at room temperature. However, inhalation can occur following exposure to the dust or to mists or vapours formed from heated or misted solutions. High concentrations of dusts or mists may irritate the nose and throat. There is no human or animal information available for sodium oxalate.

Skin Contact:
Sodium oxalate dust will absorb moisture from the skin and should be considered irritating. There is not enough information available to draw firm conclusions about the potential irritancy of sodium oxalate solutions. Therefore, these solutions should be considered irritating.
There is no specific information on the potential for skin absorption of oxalate salts.

Eye Contact:
Sodium oxalate is a very severe eye irritant, based on animal information. Permanent injury, including blindness, could result.

Ingestion:
There is no human information available for sodium oxalate. However, sodium oxalate is expected to have essentially the same toxicity as oxalic acid if ingested.(4) Oxalic acid is considered toxic to humans, based on numerous historical case reports of non-occupational poisoning. Sodium oxalate may be irritating to the mouth, and throat and stomach. Absorbed oxalic acid causes calcium ion deficiency and symptoms such as headache, muscle cramps, and tetany (sharp flexion of the wrist and ankle joints, muscle twitching, cramps and convulsions). Absorbed oxalic acid forms calcium oxalate, which is deposited in the kidneys, liver and other body tissues, and fatal kidney damage can develop. The single oral lethal dose of oxalic acid for humans is estimated to be 50-500 mg/kg. Ingestion is not a typical route of occupational exposure.

Effects of Long-Term (Chronic) Exposure

There is no human information or reliable animal information available for sodium oxalate. Sodium oxalate has essentially the same toxicity as oxalic acid if ingested.(4) For other routes of exposure there is not enough information available to determine the potential toxicity of sodium oxalate as compared to oxalic acid. However, caution is advised since long-term occupational exposure to oxalic acid has been associated with harmful skin and kidney effects in humans.

Carcinogenicity:

There is no human or animal information available.

The International Agency for Research on Cancer (IARC) has not evaluated the carcinogenicity of this chemical.

The American Conference of Governmental Industrial Hygienists (ACGIH) has no listing for this chemical.

The US National Toxicology Program (NTP) has not listed this chemical in its report on carcinogens.

Teratogenicity and Embryotoxicity:
There is no human or animal information available for sodium oxalate. Conclusions cannot be drawn based on the one limited animal study located for oxalic acid, a closely related chemical.

Reproductive Toxicity:
There is no human or animal information available for sodium oxalate. It is not possible to conclude that oxalic acid, a closely related chemical, is a reproductive toxin. Oxalic acid caused reproductive toxicity in mice in one study, but the effects were observed in the presence of a significant reduction in water consumption in the parents of the first generation and increased kidney weight in the second generation.

Mutagenicity:
There is no information available for sodium oxalate. The available information does not indicate that a closely related chemical, oxalic acid, is mutagenic.

Toxicologically Synergistic Materials:
There is no information available.

Potential for Accumulation:
Sodium oxalate is readily metabolized to oxalic acid in the body. Oxalic acid is excreted in the urine at a rate of 8-40 mg/day in healthy normal men and women. About half is excreted as oxalic acid and half as magnesium, calcium or other salts. Ingested oxalic acid is also excreted in the feces. In rats, approximately half of ingested oxalic acid is destroyed by bacterial action and about 25% is excreted unchanged in the feces. In humans, calcium oxalate is deposited in the kidneys as crystals and may be deposited in non-crystalline form, bound to lipid, in the liver and other body tissues.


SECTION 4. FIRST AID MEASURES

Inhalation:
If symptoms are experienced, remove source of contamination or move victim to fresh air. Obtain medical advice.

Skin Contact:
As quickly as possible, remove contaminated clothing, shoes and leather goods (e.g. watchbands, belts). Immediately flush with lukewarm, gently flowing water for 15-20 minutes. If irritation persists, obtain medical attention immediately. Completely decontaminate clothing, shoes and leather goods before re-use or discard.

Eye Contact:
Immediately flush the contaminated eye(s) with lukewarm, gently flowing water for 15-20 minutes, while holding the eyelid(s) open. If a contact lens is present, DO NOT delay irrigation or attempt to remove the lens. Take care not to rinse contaminated water into the unaffected eye or onto the face. Immediately obtain medical attention.

Ingestion:
NEVER give anything by mouth if victim is rapidly losing consciousness, is unconscious or convulsing. Have victim rinse mouth thoroughly with water. DO NOT INDUCE VOMITING. Have victim drink 60 to 240 mL (2 to 8 oz) of water. If vomiting occurs naturally, have victim rinse mouth with water again. Immediately obtain medical attention.

First Aid Comments:
Provide general supportive measures (comfort, warmth, rest).
Consult a doctor and/or the nearest Poison Control Centre for all exposures except minor instances of inhalation or skin contact.
All first aid procedures should be periodically reviewed by a doctor familiar with the material and its conditions of use in the workplace.



SECTION 5. FIRE FIGHTING MEASURES

Flash Point:
Not applicable. Does not form a vapour.

Lower Flammable (Explosive) Limit (LFL/LEL):
Not applicable.

Upper Flammable (Explosive) Limit (UFL/UEL):
Not applicable.

Autoignition (Ignition) Temperature:
Not applicable.

Sensitivity to Mechanical Impact:
Probably not sensitive. Stable material.

Electrical Conductivity:
Not available.

Minimum Ignition Energy:
Not applicable.

Potential for Dust Explosions:
It is not known whether sodium oxalate can cause a dust explosion. Other sodium salts of carboxylic acids (e.g. sodium acetate) have caused dust explosions.

Combustion and Thermal Decomposition Products:
Carbon monoxide, carbon dioxide, sodium oxide fumes and other irritating and toxic fumes.

Fire Hazard Summary:
Sodium oxalate does not form a vapour and is not combustible. However, it can probably burn if heated to decomposition.

Extinguishing Media:
Sodium oxalate does not burn. Use extinguishing media suitable for surrounding fire. Use water spray or fog to keep fire-exposed containers cool.

Fire Fighting Instructions:
Evacuate area and fight fire from a safe distance or a protected location. Approach fire from upwind to avoid toxic decomposition products.
Closed containers may rupture violently when exposed to the heat of the fire. If possible, isolate containers exposed to heat, but not directly involved in the fire. Move containers from the fire area if this can be done without risk. Protect personnel. Otherwise, use water in the form of spray or fog to keep fire-exposed containers cool and absorb heat to help prevent rupture, protect other fire-exposed material, prevent dust formation and to flush spills away from hazardous exposures. Solid streams of water may be ineffective and spread material. Water spray may also be used to knock down irritating/toxic combustion products which may be produced in a fire. Dike fire control water for appropriate disposal.

Protection of Fire Fighters:
Firefighters may enter the area if positive pressure self-contained breathing apparatus (NIOSH approved or equivalent) and full Bunker Gear is worn.



NATIONAL FIRE PROTECTION ASSOCIATION (NFPA) HAZARD IDENTIFICATION

NFPA - Comments:
NFPA has no listing for this chemical in Codes 49 or 325.


SECTION 9. PHYSICAL AND CHEMICAL PROPERTIES

Molecular Weight: 134.00

Conversion Factor:
Not applicable.

Physical State: Solid
Melting Point: 250-270 deg C (482-518 deg F) (decomposes) (7)
Boiling Point: Not applicable. Decomposes.
Relative Density (Specific Gravity): 2.34 at 25 deg C (water = 1) (14)
Solubility in Water: Moderately soluble (3.4 g/100 mL at 20 deg C) (15)
Solubility in Other Liquids: Insoluble in ethanol and diethyl ether.(14,15)
Coefficient of Oil/Water Distribution (Partition Coefficient): Log P(oct) = -7.0 (estimated) (16)
pH Value: 7.33 (saturated solution (3.4% or 0.25 M)) (calculated)
Acidity: Practically neutral.(6)
Viscosity-Dynamic: Not applicable.
Surface Tension: Not applicable.
Vapour Density: Not applicable.
Vapour Pressure: Not applicable. Does not form vapour.
Saturation Vapour Concentration: Not applicable.
Evaporation Rate: Not applicable.
Henry's Law Constant: Not available.

SECTION 10. STABILITY AND REACTIVITY

Stability:
Normally stable.

Hazardous Polymerization:
Does not occur.

Incompatibility - Materials to Avoid:

NOTE: Chemical reactions that could result in a hazardous situation (e.g. generation of flammable or toxic chemicals, fire or detonation) are listed here. Many of these reactions can be done safely if specific control measures (e.g. cooling of the reaction) are in place. Although not intended to be complete, an overview of important reactions involving common chemicals is provided to assist in the development of safe work practices.


STRONG OXIDIZING AGENTS (e.g. sodium chlorite or potassium permanganate) - may react violently or explosively.(8)

Hazardous Decomposition Products:
None reported.

Conditions to Avoid:
High temperatures. Generation of dust.

Corrosivity to Metals:
A saturated solution of sodium oxalate is corrosive to carbon steel and mildly corrosive to type 304 stainless steel at room temperature. It is not corrosive to aluminum and titanium.(11)

Corrosivity to Non-Metals:
A saturated solution of sodium oxalate does not attack common plastics, such as Teflon and other fluorocarbons, chlorinated polyvinyl chloride (CPVC), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC) (Saran), nylon 11, polyethylene, polypropylene, polysulfone, polyurethane and thermoset polyesters at 21 deg C.(17)

Stability and Reactivity Comments:
Decomposes if heated to the melting point (250-270 deg C).(7)


SECTION 11. TOXICOLOGICAL INFORMATION

LD50 (oral, rabbit): between 850 and 1200 mg/kg (cited as between 25 and 35 cc/kg of a 0.5N solution) (1)
LD50 (oral, mouse): 5094 mg/kg (cited as 38019 microM/kg) (2, unconfirmed)
LD50 (oral, rat): 11160 mg/kg (cited as 83284 microM/kg) (2, unconfirmed)
Note: This value appears to have been derived from an LD50 study (3), where oxalic acid was administered to rats as a 5% solution in water.

Eye Irritation:

Sodium oxalate is a severe eye irritant.

Application of 100 mg of sodium oxalate caused severe irritation in rabbits (corneal opacity: 2.33/4; iris injury: 1.22/2; redness: 3/3; chemosis: 3.44/4).(5)

Effects of Short-Term (Acute) Exposure:

Ingestion:
A historical study, which cannot be validated, reports that an oral dose of 1.8 gm of sodium oxalate killed a rabbit and 3 gm killed a cat.(9, unconfirmed)

Effects of Long-Term (Chronic) Exposure:

Ingestion:
In a limited study, two dogs given sodium oxalate or potassium oxalate twice a week, with total doses of 940 mg/kg (equivalent to 16 mg/kg/day) over 58 days and 2100 mg/kg (equivalent to 20 mg/kg/day) over 105 days, accumulated large quantities of oxalic acid in the kidney. Examination of cells from the organs of the dog dosed with 2100 mg/kg indicated kidney damage and deposits of large quantities of oxalate crystals.(10)


SECTION 16. OTHER INFORMATION

Selected Bibliography:
(1) Hermann, S. Toxicity of anious (oxalates) and catious (barium) and their detoxication. Archiv fuer Experimentelle Pathologie und Pharmakologie. Vol. 176 (1934). p. 591-598
(2) Walum, E. Acute oral toxicity. Environmental Health Perspectives. Vol. 106, suppl. 2 (Apr. 1998). p. 497-503
(3) Vernot, E.H., et al. Acute toxicity and skin corrosion data for some organic and inorganic compounds and aqueous solutions. Toxicology and Applied Pharmacology. Vol. 42, no. 2 (1977). p. 417-423
(4) Gosselin, R.E., et al. Clinical toxicology of commercial products. 5th ed. Williams & Wilkins, 1984. p. II-198, III-326-III-328
(5) Eye irritation: reference chemicals data bank. 2nd ed. Technical Report No. 48. June, 1998
(6) Sodium oxalate. The Merck index: an encyclopedia of chemicals, drugs and biologicals. Edited by M.J. O'Neil, et al. 13th ed. Merck and Company, 2001. p. 1545
(7) Lewis, Sr., R.J., ed. Sodium oxalate. Hawley's condensed chemical dictionary. [CD-ROM]. 14th ed. John Wiley and Sons, Inc., 2002
(8) Sodium oxalate. The Sigma-Aldrich library of chemical safety data. Ed. II. Vol. 2. Edited by R.E. Lenga. Sigma-Aldrich Corporation, 1988. p. 3149A
(9) Mackenzie, C.G., et al. Some effects of dietary oxalate on the rat. The American Journal of Hygiene. Vol. 25, no. 1 (Jan. 1937). p. 1-10
(10) Heubner, W. Toxicity studies on dogs (oxalate). Archiv fuer Experimentelle Pathologie und Pharmakologie. Vol. 178 (1935). p. 749-754
(11) Corrosion data survey: metals section. 6th ed. National Association of Corrosion Engineers, 1985. p. 151-3
(12) Riemenschneider, W. Oxalic acid. In: Ullmann's encyclopedia of industrial chemistry. 5th completely revised ed. Vol. A 18. VCH Publishers, 1991. p. 257
(13) European Economic Community. Commission Directive 93/72/EEC. Sept. 1, 1993
(14) Lide, D.R., ed. CRC handbook of chemistry and physics. [CD-ROM]. Chapman and Hall/CRCnetBASE, 1999
(15) Dean, J.A. Lange's handbook of chemistry. 15th ed. McGraw-Hill, Inc., 1999. p. 3.51
(16) Syracuse Research Corporation. Interactive LogKow (KowWin) Database Demo. Date unknown. Available from World Wide Web: <http://syrres.com/esc/kowdemo.htm>
(17) Pruett, K.M. Chemical resistance guide for plastics: a guide to chemical resistance of engineering thermoplastics, fluoroplastics, fibers and thermoset resins. Compass Publications, 2000. p. 494-505

Information on chemicals reviewed in the CHEMINFO database is drawn from a number of publicly available sources. A list of general references used to compile CHEMINFO records is available in the database Help.


Review/Preparation Date: 2005-08-25

Revision Indicators:
Short-term eye contact 2006-01-25



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