| Identification | More | [Name]
Sodium sulfite | [CAS]
7757-83-7 | [Synonyms]
Sodium sulfite anhydrous
SODIUM SULFITE, EXSICCATED
SODIUM SULPHITE
anhydroussodiumsulfite
disodiumsulfite
exsiccatedsodiumsulfite
natriisulphis
natriumsulfid
natriumsulfit
natriumsulfurosum
sodiumsulfite(2:1)
sodiumsulfite[na2so3]
sulfitedesodium
sulftech
Sulfurousacid,disodiumsalt
sulfurousacid,sodiumsalt(1:2)
s-wat
SODIUM SULPHITE 60-70% MIN
SODIUM SULPHITE ANHYDROU
SODIUM SULPHITE ANHYDROUS | [EINECS(EC#)]
231-821-4 | [Molecular Formula]
Na2O3S | [MDL Number]
MFCD00003503 | [Molecular Weight]
126.04 | [MOL File]
7757-83-7.mol |
| Chemical Properties | Back Directory | [Appearance]
Sodium sulfite is a white crystalline solid | [Melting point ]
500 °C
| [density ]
2.63
| [refractive index ]
1,484 | [storage temp. ]
Store at RT. | [solubility ]
H2O: 1 M at 20 °C, clear, colorless
| [form ]
Solid | [color ]
White to slightly yellow | [Specific Gravity]
2.633 | [Odor]
Odorless | [PH]
9.0-10.5 (25℃, 1M in H2O) | [PH Range]
9.0 - 10.5 at 126 g/l at 25 °C | [Stability:]
Stable. Incompatible with strong acids. Moisture and air sensitive. | [Water Solubility ]
23 g/100 mL (20 ºC) | [Sensitive ]
Hygroscopic | [Merck ]
14,8682 | [Contact allergens]
Sodium sulfite is mainly used in photographic developers, for fixing prints, bleaching textile fibers, as a reducer in manufacturing dyes, as a remover of Cl in bleached textiles and paper, and as a preservative in the food industry for meat, egg yolks, and so on.
| [Uses]
These white crystals were prepared by passing sulfurous gas over
moist sodium carbonate. Sodium sulfite is soluble in water but
less so in alcohol. It was used as a preservative for alkaline developers
and as a hypo clearing agent in photographic printing. | [CAS DataBase Reference]
7757-83-7(CAS DataBase Reference) | [NIST Chemistry Reference]
sodium sulfite(7757-83-7) | [EPA Substance Registry System]
Sodium sulfite (7757-83-7) |
| Hazard Information | Back Directory | [Chemical Properties]
Sodium sulfite,Na2S03, is a white,water-soluble, crystalline solid with a sulfurous, salty taste. It decomposes when heated. Sodium sulfite is used as a source of sulfite,as a chemical intermediate and food preservative, in medicine and paper manufacturing, in photographic developing, and as a bleaching agent in the textile industry. Most boiler operators use sodium sulfite for chemicals cavenging of oxygen in the feedwater. Because it decomposes into acidic gases at the high temperatures that accompany high pressures, sodium sulfite should not be used for this purpose at pressures above 122atm (12.4MPa,or 1.8 ksi).
| [Definition]
ChEBI: An inorganic sodium salt having sulfite as the counterion. | [General Description]
White odorless powder. Density 2.633 g/cm3. Moderately toxic. Sinks in water and dissolves slowly. Also transported as a heptahydrate Na2SO3.7H2O. | [Reactivity Profile]
SODIUM SULFITE(7757-83-7) is a reducing agent, particularly under basic conditions. Reacts with oxidizing agents such as peroxides, epoxides, oxoacids. Emits toxic fumes of sodium oxide and oxides of sulfur if heated to decomposition [Lewis, 3rd ed., 1993, p. 1174]. | [Air & Water Reactions]
Soluble in water. Reacts with hot water, steam or acids to produce corrosive material. | [Hazard]
Use prohibited in meats and other sources
of Vitamin B
1 | [Health Hazard]
When ingested, solutions cause gastric irritation by the liberation of sulfurous acid. Because of rapid oxidation to sulfate, sulfites are well tolerated until large doses are reached; then violent colic and diarrhea, circulatory disturbances, central nervous depression, and death can occur. | [Potential Exposure]
Sodium sulfite is used as a reducing agent; in boiler water treatment; food applications; in photographic developers and fixers; in bleaching of wool, paper, textiles, straw and silk; manufacture of dyes; dechlorination; preservation of meat, fruit and egg products; silvering of glass. | [Fire Hazard]
Literature sources indicate that this compound is noncombustible. | [First aid]
Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; give artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. For minor skin contact, avoid spreading material on unaffected skin. Keep victim warm and quiet. Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed. Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Medical observation is recommended for 24 to 48 hours after breathing overexposure, as pulmonary edema may be delayed. As first aid for pulmonary edema, a doctor or authorized paramedic may consider administering a drug or other inhalation therapy. | [Shipping]
UN3260 Corrosive solid, acidic, inorganic, n.o.s., Hazard class: 8; Labels: 8-Corrosive material. | [Incompatibilities]
A strong reducing agent. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases. Reacts with strong acids producing toxic sulfur dioxide. | [Production Methods]
Sodium bisulfite is prepared by reacting sulfur dioxide gas with
sodium hydroxide solution. The solid material is obtained by
evaporation of water. Further neutralization with sodium hydroxide
while keeping the temperature above 33.6°C leads to crystallization
of the anhydrous sodium sulfite (below this temperature the
heptahydrate form is obtained). | [Pharmaceutical Applications]
Sodium sulfite is used as an antioxidant in applications similar to
those for sodium metabisulfite. It is also an effective antimicrobial
preservative, particularly against fungi at low pH (0.1% w/v of
sodium sulfite is used). Sodium sulfite is used in cosmetics, food
products, and pharmaceutical applications such as parenteral
formulations, inhalations, oral formulations, and topical preparations. | [Safety]
Sodium sulfite is widely used in food and pharmaceutical
applications as an antioxidant. It is generally regarded as relatively
nontoxic and nonirritant when used as an excipient. However,
contact dermatitis and hypersensitivity reactions have been
reported. The acceptable daily intake for sodium sulfite has
been set at up to 350 mg/kg body-weight daily.
LD50 (mouse, IP): 0.950 g/kg
LD50 (mouse, IV): 0.130 g/kg
LD50 (mouse, oral): 0.820 g/kg
LD50 (rabbit, IV): 0.065 g/kg
LD50 (rabbit, oral): 1.181 g/kg
LD50 (rat, IV): 0.115 g/kg | [Environmental Fate]
Because sodium sulfite is a solid powder that is generally sold
as a ‘food grade’ substance, there is very little information
available on the environmental fate of sodium sulfite. It has
a molecular weight of 126.04 g mol-1. At 20°C, the solubility
in water is 250 000 mg l-1, and as it is an inorganic salt the
vapor is negligible (USEPA, 2011). The log octanol/water
partition coefficient is estimated to be 7.78.
If released into water or soil, sodium sulfite would most
likely be oxidized to sulfate, which would then be available for
use by bacteria or plants as a nutrient.
The US Environmental Protection Agency (EPA) EPI Suite
computer program (USEPA, 2011) estimates both a bioconcentration
factor and a bioaccumulation factor of 0.89. These
factors are less than one, meaning that bioconcentration and/or
bioaccumulation of sodium sulfite would be virtually negligible
and therefore would not cause any adverse effects to fish and
wildlife. | [storage]
Sodium sulfite should be stored in a well-closed container in a cool,
dry, place. In solution, sodium sulfite is slowly oxidized to sulfate by dissolved oxygen; strong acids lead to formation of sulfurous acid/
sulfur dioxide. On heating, sodium sulfite decomposes liberating
sulfur oxides. | [Purification Methods]
Crystallise the sulfite from warm water (0.5mL/g) by cooling to 0o. Also purify it by repeated crystallisation from deoxygenated water inside a glove-box, and finally drying it under vacuum. [Rhee & Dasgupta J Phys Chem 89 1799 1985.] | [Toxicity evaluation]
The exact mechanism of toxicity has not been elucidated,
although there is a lot of information on how sulfur-based
compounds are detoxified by the liver. Sodium sulfite is
a mild reducing agent that would most likely cause burning or
irritation at the site of exposure or application by altering
oxidation–reduction potential and pH.
Sulfites are used widely as antioxidants to keep foods from
prematurely spoiling and to keep them looking ‘fresh’ by preventing
oxidation and subsequent ‘browning.’ Many people,
however, are ‘sulfite sensitive.’ After ingestion of food or
beverages containing sulfite, these people may have allergictype
reactions such as asthmatic wheezing, hypotension,
tingling sensations, and flushing of the skin. The mechanism is
unclear but probably has to do with an individual-specific
chemical stimulation of the immune system, which in turn
releases small amounts of vasoactive substances. | [Regulatory Status]
GRAS listed. Accepted for use as a food additive in Europe.
Included in FDA Inactive Ingredients Database (epidural, IM, IV,
and SC injections; inhalation solution; ophthalmic solutions; oral
syrups and suspensions; otic solutions; topical creams and emulsions).
Included in nonparenteral medicines licensed in the UK. |
| Safety Data | Back Directory | [Hazard Codes ]
Xn | [Risk Statements ]
R31:Contact with acids liberates toxic gas.
R36/37/38:Irritating to eyes, respiratory system and skin .
R22:Harmful if swallowed.
R40:Limited evidence of a carcinogenic effect.
R36/38:Irritating to eyes and skin . | [Safety Statements ]
S24/25:Avoid contact with skin and eyes .
S36:Wear suitable protective clothing .
S26:In case of contact with eyes, rinse immediately with plenty of water and seek medical advice .
S22:Do not breathe dust . | [WGK Germany ]
1
| [RTECS ]
WE2150000
| [F ]
3-10 | [TSCA ]
Yes | [HS Code ]
28321000 | [Safety Profile]
Poison by intravenous and subcutaneous routes. Moderately toxic by ingestion and intraperitoneal routes. Human mutation data reported. When heated to decomposition it emits very toxic fumes of Na2O and SOx. A reducing agent. See also SULFITES. | [Hazardous Substances Data]
7757-83-7(Hazardous Substances Data) | [Toxicity]
LD50 i.v. in mice: 175 mg/kg, Hoppe, Goble, J. Pharmacol. Exp. Ther. 101, 101 (1951) |
| Questions And Answer | Back Directory | [Description]
As a soluble sodium salt of sulfurous acid, Sodium sulfite (Na2SO3) shows blenching, de-sulfurizing and dechlorinating properties which is widely applied in various fields. It is primarily used in the pulp and papermaking industry due to its blenching activity. It can serve as a good additive to help preserve the fresh appearance of good products. Besides, sodium sulfite is a component in many pharmaceuticals, which is effective to maintain the potency and stability of drugs. It can also be applied for water treatment as an oxygen scavenger agent and applied in flue gas desulfurization and preservation of photo developer solutions, etc.
| [Uses]
Sodium sulfite (Na2SO3) is an antioxidant, used as a preservative except with meats. It is
also used for water treatment and in photography and textile bleaching. | [References]
https://en.wikipedia.org/wiki/Sodium_sulfite
https://pubchem.ncbi.nlm.nih.gov/compound/24437#section=Top
http://www.calabriancorp.com/product/sodium-sulfite-anhydrous
http://www.livestrong.com/article/108427-list-foods-sulfite-allergies/
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