Sodium bisulfite

Not to be confused with Sodium bisulfate.

Sodium bisulfite

Ball-and-stick model of a bisulfite anion (left) and a sodium cation (right)
Names
IUPAC name Sodium hydrogen sulfite
Other names E222 sodium bisulphite
Identifiers
CAS Number	7631-90-5  Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:26709  Y
ChEMBL	ChEMBL1689285  N
ChemSpider	571016  Y
ECHA InfoCard	100.028.680
E number	E222 (preservatives)
PubChem CID	23665763
RTECS number	VZ2000000
UNII	TZX5469Z6I  Y
CompTox Dashboard (EPA)	DTXSID8034902
InChI InChI=1S/Na.H2O3S/c;1-4(2)3/h;(H2,1,2,3)/q+1;/p-1 Y Key: DWAQJAXMDSEUJJ-UHFFFAOYSA-M Y InChI=1/Na.H2O3S/c;1-4(2)3/h;(H2,1,2,3)/q+1;/p-1 Key: DWAQJAXMDSEUJJ-REWHXWOFAL
SMILES [Na+].[O-]S(=O)O
Properties
Chemical formula	NaHSO3
Molar mass	104.061 g/mol
Appearance	White solid
Odor	Slight sulfurous odor
Density	1.48 g/cm3
Melting point	150 °C (302 °F; 423 K)
Boiling point	315 °C (599 °F; 588 K)
Solubility in water	42 g/100 mL
Refractive index (nD)	1.526
Hazards
GHS labelling:
Pictograms
Hazard statements	H302
Precautionary statements	P301+P312+P330
NFPA 704 (fire diamond)	2 0 1
Flash point	Non-flammable
NIOSH (US health exposure limits):
PEL (Permissible)	none [1]
REL (Recommended)	TWA 5 mg/m3 [1]
IDLH (Immediate danger)	N.D. [1]
Related compounds
Other anions	Sodium sulfite Sodium metabisulfite Sodium biselenite
Other cations	Potassium bisulfite
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N  verify  (what is  YN ?) Infobox references

Sodium bisulfite (or sodium bisulphite, sodium hydrogen sulfite) is a chemical mixture with the approximate chemical formula NaHSO₃. Sodium bisulfite is not a real compound, ^[2] but a mixture of salts that dissolve in water to give solutions composed of sodium and bisulfite ions. It appears in form of white or yellowish-white crystals with an odor of sulfur dioxide. Sodium bisulfite is used in a variety industries such as a food additive with E number E222 in the food industry. It is a reducing agent in the cosmetic and in the bleaching applications. ^{[3] [4] [5]}

Synthesis

Sodium bisulfite solutions can be prepared by treating a solution of suitable base, such as sodium hydroxide or sodium bicarbonate with sulfur dioxide.

SO₂ + NaOH → NaHSO₃

SO₂ + NaHCO₃ → NaHSO₃ + CO₂

Attempts to crystallize the product yield sodium metabisulfite (also called sodium disulfite), Na₂S₂O₅. ^[6]

Upon dissolution of the metabisulfite in water, bisulfite is regenerated:

Na₂S₂O₅ + H₂O → 2 Na⁺ + 2 HSO₃⁻

Sodium bisulfite is formed during the Wellman-Lord process. ^[7]

Uses

Cosmetics

Sodium bisulfite functions as a hair-waving/straightening agent. ^[8] As of 1998, sodium bisulfite was used in 58 cosmetic products including hair conditioners, moisturizers, and hair dyes. ^[9]

Food industry

Sodium bisulfite is used to prevent discoloration, bleach food starches, and delay spoilage of the product. In the US, EPA, FDA, and American Conference of Governmental Industrial Hygienists established a working place threshold limit value for sulfur dioxide of 2ppm averaged over 8 hours, and a 3-hour level of 5ppm. Even with this threshold established, the FDA recognized sodium bisulfite as "generally recognized as safe" compound. ^[3]

Sulfites in food can be assayed by the Monier-Williams type procedure, ^[10] HPLC after extraction, and Flow Injection analysis. ^[5]

Textile industry

Sodium bisulfite is used as an antichlor in the textile industry. ^{[3] [4]} Antichlors are very useful in the textile industry because bleaching of compounds using chlorine is a standard practice.

Safety

The International Agency for Research on Cancer concluded that there was inadequate evidence that sodium bisulfite was carcinogenic. ^[3] Under specific conditions such as acidity and concentration level, sodium bisulfite was able to cause negative alterations to the genome such as catalyzing transamination, and to induce sister-chromatid exchanges suggesting possible genotoxicity. ^[11] In a study using Osbourne-Mendel strain rats, it was concluded that oral toxicity was not significant if the consumed concentration was less than 0.1% (615 ppm as SO₂). ^[12] A study by Servalli, Lear, and Cottree in 1984 found that sodium bisulfite did not produce membrane fusion in hepatic and murine glial cells and human fibroblasts, so there is no oral toxicity. These clinical studies concluded that sodium bisulfite was safe to use in cosmetic formulations. ^[3]

The concentrations of sodium bisulfite that could be dangerous are well beyond the concentrations discussed in the cosmetic and food industry.. ^{[4] [13]}

The World Health Organization Expert Committee on Food Additives concluded that 0-0.7mg of sulfur dioxide equivalent/kg of body weight per day will cause no harm to an individual consuming this compound as a food additive. Sulfites exhibit no genotoxicity and carcinogenicity. ^[5]

See also

• Sodium metabisulfite
• Calcium bisulfite
• Potassium bisulfite
• Croscarmellose sodium
• Sulfurous acid

References

1. NIOSH Pocket Guide to Chemical Hazards. "#0561". National Institute for Occupational Safety and Health (NIOSH).
2. Tudela, David; Jenkins, H. Donald B. (2003). "New Methods to Estimate Lattice Energies: Application to the Relative Stabilities of Bisulfite (HSO₃⁻) and Metabisulfite (S₂O₅^2-) Salts" . Journal of Chemical Education . 80 (12): 1482. Bibcode:2003JChEd..80.1482T. doi:10.1021/ed080p1482.
3. Nair, B.; Elmore, A. R.; Cosmetic Ingredients Review Expert Panel (2003-06-01). "Final Report on the Safety Assessment of Sodium Sulfite, Potassium Sulfite, Ammonium Sulfite, Sodium Bisulfite, Ammonium Bisulfite, Sodium Metabisulfite and Potassium Metabisulfite". International Journal of Toxicology . 22 (2 Suppl): 63–88. doi:10.1080/10915810305077X. ISSN   1091-5818. PMID   14555420.
4. Periyasamy, A.P.; Militky, J. (2017), "Denim processing and health hazards" , Sustainability in Denim, Elsevier, pp. 161–196, doi:10.1016/b978-0-08-102043-2.00007-1, ISBN   978-0-08-102043-2 , retrieved 2022-05-11
5. EFSA Panel on Food additives and Nutrient Sources added to Food (ANS) (2016). "Scientific Opinion on the re-evaluation of sulfur dioxide (E 220), sodium sulfite (E 221), sodium bisulfite (E 222), sodium metabisulfite (E 223), potassium metabisulfite (E 224), calcium sulfite (E 226), calcium bisulfite (E 227) and potassium bisulfite (E 228) as food additives". EFSA Journal . 14 (4). doi: 10.2903/j.efsa.2016.4438 .
6. Johnstone, H. F. (1946). "Sulfites and Pyrosulfites of the Alkali Metals". Inorganic Syntheses . Inorganic Syntheses. Vol. 2. pp. 162–167. doi:10.1002/9780470132333.ch49. ISBN   9780470132333.
7. Kohl, Arthur L.; Nielsen, Richard B. (1997). "Sulfur Dioxide Removal" . Gas Purification. Gulf Professional Publishing. pp. 554–555. ISBN   978-0-88415-220-0.
8. Leite, Marcella Gabarra Almeida; Garbossa, Wanessa Almeida Ciancaglio; Campos, Patricia Maria Berardo Gonçalves Maia (2018-11-29). "Hair straighteners: an approach based on science and consumer profile". Brazilian Journal of Pharmaceutical Sciences. 54 (3). doi: 10.1590/s2175-97902018000317339 . ISSN   2175-9790.
9. Cherian, Priya; Zhu, Jinqiu; Bergfeld, Wilma F.; Belsito, Donald V.; Hill, Ronald A.; Klaassen, Curtis D.; Liebler, Daniel C.; Marks, James G.; Shank, Ronald C.; Slaga, Thomas J.; Snyder, Paul W. (2020). "Amended Safety Assessment of Parabens as Used in Cosmetics". International Journal of Toxicology . 39 (1_suppl): 5S –97S. doi:10.1177/1091581820925001. ISSN   1091-5818. PMID   32723119. S2CID   220850521.
10. "Reevaluation of Monier-Williams method for determining sulfite in food". Journal of AOAC International . Oxford University Press . Retrieved 2022-09-20.
11. Abe, Syuiti; Sasaki, Motomichi (1977). "Chromosome Aberrations and Sister Chromatid Exchanges in Chinese Hamster Cells Exposed to Various Chemicals 2" . Journal of the National Cancer Institute . 58 (6): 1635–1641. doi:10.1093/jnci/58.6.1635. ISSN   1460-2105. PMID   864744.
12. Jonker, D.; Woutersen, R.A.; van Bladeren, P.J.; Til, H.P.; Feron, V.J. (1990). "4-Week oral toxicity study of a combination of eight chemicals in rats: Comparison with the toxicity of the individual compounds" . Food and Chemical Toxicology . 28 (9): 623–631. doi:10.1016/0278-6915(90)90170-R. PMID   2272560.
13. Nagayama, Hirotoshi; Hatamochi, Atsushi; Shinkai, Hiroshi (1997). "A Case of Contact Dermatitis Due to Sodium Bisulfite in an Ophthalmic Solution" . The Journal of Dermatology. 24 (10): 675–677. doi:10.1111/j.1346-8138.1997.tb02315.x. PMID   9375469. S2CID   21945156.