Щавелевая кислота

90.034

90.03

208-932-1

9E7R5L6H31

0529

62774

3261|1759

DTXSID0025816

ANHYDROUS OXALIC ACID, CRYSTALLIZED FROM GLACIAL ACETIC ACID IS ORTHORHOMBIC, CRYSTALS BEING PYRAMIDAL OR ELONGATED OCTAHEDRA|Colorless powder or granular solid [Note: The anhydrous form (COOH)2 is a white powder].

2917111000

74.6

-0.3

Oxalic acid is an odorless white solid. Sinks and mixes with water. (USCG, 1999)

1.9 g/cm³

189.5 °C (decomp)

200 °C @ Press: 0.1 Torr

188.8±19.7 °C

1.480

14%

STORE IN COOL, DRY, WELL-VENTILATED LOCATION. /OXALIC ACID DIHYDRATE/

<0.001 mmHg

4.3

Combustible Solid

Odorless.

1.43e-10 atm-m3/mole|Henry's Law constant: 1.4X10-10 atm-cu m/mole at 25 °C (experimental)

pKa 1: 1.46; pKa 2: 4.40

MP: 101-102 °C GIVING OFF WATER OF CRYSTALLIZATION & STARTING TO SUBLIME; K1= 5.36X10-2; K2= 5.3X10-5; DENSITY: 1.653 @ 18.5 °C/4 °C; DENSITY OF 1% (WT/WT) AQ SOLN: 1.0035 @ 17.5 °C/4 °C; DENSITY OF 3% (WT/WT) AQ SOLN: 1.0105 @ 17.5 °C/4 °C; DENSITY OF 5% (WT/WT) AQ SOLN: 1.0175 @ 17.5 °C/4 °C; DENSITY OF 10% (WT/WT) AQ SOLN: 1.0350 @ 17.5 °C/4 °C; DENSITY OF 13% (WT/WT) AQ SOLN: 1.0455 @ 17.5 °C/4 °C /OXALIC ACID DIHYDRATE/|DISSOCIATION CONSTANT: 6.5X10-2 /OXALIC ACID DIHYDRATE/|SUBLIMES BEST @ 157 °C; @ HIGHER TEMP DECOMP INTO CO2, CARBON MONOXIDE, FORMIC ACID, & WATER; HYGROSCOPIC|MONOCLINIC TABLETS, PRISMS, OR GRANULES; 1 G DISSOLVES IN 7 ML WATER; 1 G DISSOLVES IN 2 ML BOILING WATER; 1 G DISSOLVES IN 2.5 ML ALCOHOL; 1 G DISSOLVES IN 1.8 ML BOILING ALCOHOL; 1 G DISSOLVES IN 100 ML ETHER; 1 G DISSOLVES IN 5.5 ML GLYCEROL /OXALIC ACID DIHYDRATE/|Transparent, colorless crystals or white powder /Oxalic acid dihydrate/|Odorless /Oxalic acid dihydrate/|For more Other Experimental Properties (Complete) data for OXALIC ACID (6 total), please visit the HSDB record page.

Water soluble. Hygroscopic

Acids, Carboxylic

OXALIC ACID is hygroscopic and sensitive to heat. This compound may react violently with furfuryl alcohol, silver, sodium, perchlorate, sodium hypochlorite, strong oxidizers, sodium chlorite, acid chlorides, metals and alkali metals. (NTP, 1992). The heating of mixtures of Oxalic acid and urea has lead to explosions. This is due to the rapid generation of the gases CO2, CO, and NH3 [Praxis Naturwiss. Chem., 1987, 36(8), 41-42]. Oxalic acid and urea react at high temperatures to form toxic and flammable ammonia and carbon monoxide gases, and inert CO2 gas [Von Bentzinger, R. et al., Praxis Naturwiss. Chem., 1987, 36(8), 41-42].

Not flammable (USCG, 1999)

-245.61 KJ/mol

Combustible Solid

III

8

UN 3261 8/PG 3

1

R21/22

S24/25-S23-S36/37/39-S27-S26

RO2450000

Xn:Harmful

Separated from strong oxidants and food and feedstuffs. Dry. Well closed.

OXALIC ACID CAN BE DEHYDRATED BY CAREFUL DRYING @ 100 DEG C, BUT LOSSES OCCUR THROUGH SUBLIMATION /OXALIC ACID DIHYDRATE/

P280-P305 + P351 + P338

H302 + H312-H318

Oxalic acid is a waste chemical stream constituent which may be subjected to ultimate disposal by controlled incineration. Pretreatment involves chemical reaction with limestone or calcium oxide forming calcium oxalate. This may then be incinerated utilizing particulate collection equipment to collect calcium oxide for recycling.

Reacts with strong alkalies, strong oxidizing materials, chlorites, and hypochlorites. /Oxalic acid dihydrate/|Strong oxidizers, silver compounds, strong alkalis, chlorites [Note: Gives off water of crystallization at 215 degrees F and begins to sublime].

UN 3261

P280; P301 + P312 + P330; P305 + P351 + P338 + P310

Special Hazards of Combustion Products: Generates poisonous gases (USCG, 1999)|Combustible. Gives off irritating or toxic fumes (or gases) in a fire.

|Warning|H302: Harmful if swallowed [Warning Acute toxicity, oral]|P264, P270, P280, P301+P312, P302+P352, P312, P322, P330, P363, and P501|Danger|H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]|P264, P270, P280, P301+P312, P302+P352, P305+P351+P338, P310, P312, P322, P330, P363, and P501|Aggregated GHS information provided by 1220 companies from 17 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|P260, P264, P270, P280, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P314, P321, P322, P330, P363, P405, and P501|P201, P202, P260, P261, P264, P270, P271, P273, P280, P281, P301+P312, P302+P352, P304+P340, P305+P351+P338, P307+P311, P308+P313, P310, P312, P314, P321, P330, P332+P313, P362, P403+P233, P405, and P501|P201, P202, P260, P264, P270, P280, P281, P301+P312, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P308+P313, P309+P311, P310, P314, P321, P330, P363, P405, and P501

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]: As an 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. SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above. 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, 2016)

Neutralizing Agents for Acids and Caustics: Lime or soda ash (USCG, 1999)

Skin: Wear appropriate personal protective clothing to prevent skin contact. Eyes: Wear appropriate eye protection to prevent eye contact. Wash skin: The worker should immediately wash the skin when it becomes contaminated. Remove: Work clothing that becomes wet or significantly contaminated should be removed and replaced. Change: Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premise. Provide: Eyewash fountains should be provided in areas where there is any possibility that workers could be exposed to the substance; this is irrespective of the recommendation involving the wearing of eye protection. (NIOSH, 2016)|... EYE & SKIN PROTECTION /MUST/ BE PROVIDED FOR PERSONS WORKING WITH OXALIC ACID.|Wear special protective clothing and positive pressure self-contained breathing apparatus. /Oxalic acid dihydrate/|If mists of oxalic acid should be encountered from hot solutions ... adequate ventilation should be provided or proper respiratory protective devices worn.|Respirator for dust or mist protection; rubber, neoprene, or vinyl gloves; chemical safety glasses; rubbers, over leather or rubber safety shoes; apron or impervious clothing for splash protection.|For more Personal Protective Equipment (PPE) (Complete) data for OXALIC ACID (12 total), please visit the HSDB record page.|(See protection codes)

USE WATER SPRAY, DRY CHEM, "ALC RESISTANT" FOAM, OR CARBON DIOXIDE. DUST MAY BE REDUCED WITH WATER SPRAY. AQUEOUS SOLUTION MUST BE CONTAINED FOR DISPOSAL. USE WATER TO KEEP FIRE-EXPOSED CONTAINERS COOL. WATER MAY CAUSE FOAMING OF MOLTEN MATERIAL. /OXALIC ACID DIHYDRATE/

Cover with soda ash or sodium bicarbonate. Mix and add water. Neutralize and drain into a drain with sufficient water.

Adequate ventilation.|The worker should immediately wash the skin when it becomes contaminated.|Work clothing that becomes wet or significantly contaminated should be removed and replaced.|Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premises.|For more Preventive Measures (Complete) data for OXALIC ACID (6 total), please visit the HSDB record page.

The chief effects of inhalation of the dust or vapor are irritation of the eyes and upper respiratory tract.

Permissible Exposure Limit: Table Z-1 8-hr Time Weighted Avg: 1 mg/cu m.|Vacated 1989 OSHA PEL TWA 1 mg/cu m; STEL 2 mg/cu m is still enforced in some states.

Recommended Exposure Limit: 10 Hr Time-Weighted Avg: 1 mg/cu m.|Recommended Exposure Limit: 15 Min Short-Term Exposure Limit: 2 mg/cu m.

Personal protection: particulate filter respirator adapted to the airborne concentration of the substance, protective gloves and safety goggles. Sweep spilled substance into covered plastic containers. If appropriate, moisten first to prevent dusting. Wash away remainder with plenty of water.

Separated from strong oxidants and food and feedstuffs. Dry. Well closed.

Evaporation at 20 °C is negligible; a harmful concentration of airborne particles can, however, be reached quickly when dispersed.

The substance is corrosive to the eyes, skin and respiratory tract. Corrosive on ingestion. The substance may cause effects on the calcium balance after ingestion. Exposure at high levels could cause death.

Repeated or prolonged contact with skin may cause dermatitis. Exposure may result in kidney stones, slow-healing ulcers and black finger nails.

NO open flames.

PREVENT DISPERSION OF DUST!

Use ventilation (not if powder), local exhaust or breathing protection.

Protective gloves. Protective clothing.

Wear face shield or eye protection in combination with breathing protection.

| 3 - Materials that, under emergency conditions, can cause serious or permanent injury.| 1 - Materials that must be preheated before ignition can occur. Materials require considerable preheating, under all ambient temperature conditions, before ignition and combustion can occur.| 0 - Materials that in themselves are normally stable, even under fire conditions.

Oxalic acid has been qualitatively detected in pulp mill effluents(1). Oxalic acid was identified in two prebleaching spent liquors of kraft pulp mill effluents at concns of 0.5 and 6 g/ton of pulp(2). It was detected during kraft pulp bleaching at a concn of 130 g/ton in a spent chlorination liquor and 590 g/ton in a spent alkali extraction liquor(3). Oxalic acid was identified in the automobile exhaust of a 1982 Toyota Corolla at a concn of 182 nmole/cu-m(4). It was also identified at a concn of 482 nmole/cu-m in automobile exhaust from a 1971 Mercedes Benz(4).

Oxalic acid was detected at concns ranging from 30 to 6 mg/kg in soil 0 to 540 cm, respectively, below the surface at a site in Germany(1). Oxalic acid was identified in 2 soil samples taken from the UCLA campus (Los Angeles, CA) at concns of 166 and 156 nmol/g(2). Oxalic acid was detected in 2 fractions of bog sediment from the Los Angeles, CA area at concns of 1,410 (humic acid fraction) and 3,350 (fulvic acid fraction) nmol/g(2). Significant concns of oxylate (dissolved plus particulate) were present in sediments taken from a diversity of aquatic environments, ranging from 0.1 to 0.7 mmol/l of sediment(3). These included pelagic and littoral sediments from two freshwater lakes (Searsville Lake, CA and Lake Tahoe, CA), a hypersaline, meromictic, alkaline lake (Big Soda Lake, NV), and a south San Francisco Bay mud flat and salt marsh(3).

URBAN/SUBURBAN: Oxalic acid was the dominant species of dicarboxylic acids in the range C2-C10 identified in the Los Angeles, CA ambient atmosphere(1). In June, 1984, oxalic acid was detected in west Los Angeles air at concns of 6.38 and 2.12 nmol/cu-m(1). Oxalic acid was detected in west Los Angeles ambient air in 6 samples at a concn range of 3.40 to 8.65 nmol/cu-m and an average concn of 5.4 nmol/cu-m in October, 1984(1). In the same study during October of 1984, it was detected in 2 samples taken from downtown Los Angeles at concns of 6.60 and 8.31 nmol/cu-m(1). Oxalic acid was also detected in greenhouse air at UCLA (Los Angeles, CA) in December of 1984 at concns of 1.31 and 2.83 nmol/cu-m(1). Oxalic acid was detected in airborne aerosols above Takasaki and Karuizawa, Japan at average concns of 5.1 and 3.8 ng/cu-m, respectively, during July of 1986(2). Oxalic acid was detected at a concn of approximately 3 ng/cu-m in airborne particulate matter in a suburban area in Japan(3). In September of 1985, oxalic acid was detected in the ambient atmosphere of Claremont, CA in 12 of 12 samples taken at a concn range of <0.12 to 0.94 ug/cu-m(4).

Oxalic acid was identified in greenhouse dust and dust from downtown Los Angeles, CA at a concns of 2,330 and 2,510 nmol/g, respectively(1).