Sodium perborate
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Other names
Sodium peroxoborate,[1] PBS-1 ("monohydrate"), PBS-4 ("tetrahydrate")
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Identifiers | |
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3D model (
JSmol ) |
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ChEBI | |
ChemSpider | |
ECHA InfoCard
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100.035.597 |
EC Number |
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PubChem CID
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RTECS number
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UNII |
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UN number | 1479 |
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Properties | |
NaBO3·nH2O | |
Molar mass | 99.815 g/mol ("monohydrate"); 153.86 g/mol ("tetrahydrate") |
Appearance | White powder |
Odor | Odorless |
Melting point | 63 °C (145 °F; 336 K) ("tetrahydrate") |
Boiling point | 130 to 150 °C (266 to 302 °F; 403 to 423 K) ("tetrahydrate", decomposes) |
2.15 g/(100 mL) ("tetrahydrate", 18 °C) | |
Pharmacology | |
A01AB19 (WHO) | |
Hazards | |
NFPA 704 (fire diamond) | |
Flash point | Non-flammable |
Safety data sheet (SDS) | ICSC 1046 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Sodium perborate is chemical compound whose chemical formula may be written NaH2BO4, Na2H4B2O8, or, more properly, [Na+]2[B2O4(OH)4]2−. Its name is sometimes abbreviated as PBS (not to be confused with phosphate-buffered saline).
The compound is commonly encountered in anhydrous form or as a hexahydrate (commonly called "monohydrate" or PBS-1 and "tetrahydrate" or PBS-4, after the early assumption that NaBO3 would be the anhydrous form).[2] They are both white, odorless, water-soluble solids.[3]
This salt is widely used in laundry detergents, as one of the peroxide-based bleaches.
Structure
Unlike
Hydrates
The compound also crystallizes from water as the hexahydrate, Na2H4B2O8·6H2O, that is, Na2H16B2O14 or NaH8BO7.[citation needed]
The anhydrous compound is commonly but incorrectly called a "monohydrate" after the historical formulation NaBO3·H2O instead of the correct Na2H4B2O8. Likewise, the hexahydrate is usually called "tetrahydrate" and formulated as NaBO3·4H2O.[2] Both forms are white, odorless, water-soluble solids.[3] The "monohydrate" and the "tetrahydrate" are the commercially important forms.[3]
There does exist a true tetrahydrate Na2H4B2O8·4H2O, traditionally known as the "trihydrate", with no industrial significance. There is a
Chemistry
Sodium perborate undergoes hydrolysis in contact with water, producing hydrogen peroxide and borate.[3]
More precisely, in solution the cyclic anion hydrolizes into two anions [B(OH)3(OOH)]−, which then enter in equilibrium with boric acid B(OH)3, hydrogen peroxide H2O2, the hydroperoxyl anion −OOH, and the tetrahydroxyborate anion [B(OH)4]−:[2]
- [(B(OH)2OO)2]2− + 2 H2O ⇌ 2 [B(OH)3(OOH)]−
- [B(OH)3(OOH)]− ⇌ B(OH)3 + −OOH
- B(OH)3 + −OOH + H2O ⇌ [B(OH)4]− + H2O2
As the concentration of the solution increases, other peroxoborate species become significant. With excess H2O2, the anions [B(OH)2(OOH)2]−, [B(OH)(OOH)3]−, and eventually [B(OOH)4]− appear. At high borate concentrations, the sodium perborate with dimeric anion crystallizes out, due to its relatively low solubility.[2]
The "monohydrate" form dissolves faster than the "tetrahydrate" and has higher heat stability; it is prepared by heating the "tetrahydrate".[1] The commercial "anhydrate", or Oxoborate, is prepared by further heating of "monohydrate" and actually consists of sodium borate and boron–oxygen radical.[1]
Preparation
Sodium perborate is manufactured by reaction of borax Na2B4O7 and sodium hydroxide NaOH to give sodium metaborate NaBO2, which is then reacted with hydrogen peroxide to give hydrated sodium perborate:[3][6]
- Na2B4O7 + 2 NaOH → 4 NaBO2 + H2O
- 2 NaBO2 + 2 H2O2 → Na2B2O4(OH)4
A surfactant may be added to control crystal size.[7][8]
It may also be produced in the electrolysis of an aqueous solution of a solution containing borax, sodium carbonate and sodium bicarbonate (potassium dichromate is added to improve yield along with sodium silicate). A copper pipe is used as a cathode and platinum for the anode, the current being 6 amperes at 7 to 8 volts, and the temperature 10 °C.[9]
Uses
Sodium perborate serves as a stable source of
The compound has antiseptic properties and can act as a disinfectant. It is also used as a "disappearing" preservative in some brands of eye drops.[citation needed]
Sodium perborate is also used as an
Dental use
Sodium perborate monohydrate is quickly hydrolyzed into hydrogen peroxide and borate on contact with water.[3] A 1979 double-blind crossover study[11] suggests that hydrogen peroxide, which is released during the use of this product, may prevent or retard colonization and multiplication of anaerobic bacteria, such as those that inhabit oral wounds.
Sodium perborate is also present in some
Safety
In the European Union, sodium perborate, like most borates, was classified as "carcinogenic, mutagenic, or toxic for reproduction" (CMR), category 1B of Regulation (EC) 790/2009, as a result of being included in Part 3 of Annex VI of the regulation 1272/2008 on Classification, Labelling and Packaging (CLP) of substances and mixtures. As a result, their use has been automatically banned in cosmetic products in the EU, in any concentration, starting 1 December 2010. That extends to the use of perborates for tooth whitening.[12]
Brands
Bocasan
Bocasan was an oral wound cleanser manufactured in the United Kingdom by Knox Laboratories Ltd of London from 1960–1975,[13] before being rebranded as an Oral-B product [14]
Production of Bocasan appears to have ceased by 2003. A similar product,
It was used to aid treatment, in adults or children over 5 years old, of
Bocasan was packaged in a 1.7 gram envelope, and contained 69.72% sodium perborate monohydrate and 29.68% sodium hydrogen tartrate anhydrous. To use, the contents were dissolved in 30 cubic centimetres of warm water. Half the amount was swilled around the mouth for two minutes and discarded, and the procedure repeated with the remainder. Treatment was recommended three times a day after meals.
A 1979 double-blind crossover study[16] suggests that hydrogen peroxide, which is released during the use of this product, may prevent or retard colonization and multiplication of anaerobic bacteria, such as those that inhabit oral wounds. A small (n=12) 1998 RCT shows that Bocasan combined with chlorhexidine mouthwash is better than chlorhexidine alone in preventing plaque.[17] A further study (n=28) shows that Bocasan reduces the staining associated with chlorhexidine.[18]
Drug facts
- Active ingredient: Sodium perborate monohydrate
- Inactive ingredients: Sodium hydrogen tartrate
- Purpose: Oral cleanser
- Normal use: Use up to three times daily, after meals or as directed by a dentist
Amosan
Amosan
History
Amosan was originally made by Oral-B; a mention of the powder appeared in the February 6, 1970 Federal Register.[20] Between 2005 and 2010, Amosan was manufactured in Belgium and sold under the Oral-B brand, belonging to Procter & Gamble after its 2005 acquisition of Gillette. In December 2010, its use was banned in the EU, as the product is based on borate, which the union considers "carcinogenic, mutagenic, or toxic for reproduction".[12]
Vintage Brands Limited began manufacturing and selling Amosan Oral Antiseptic Rinse in 2014 because many consumers were disappointed that it was no longer available.[21] Product review pages on Amazon[22] and public comment forums elsewhere[23] indicate a high level of frustration with the discontinuation by users who could find no effective alternative treatment.
In April 2012, it was reported that Shoppers Drug Mart in Canada had produced a comparable product under their house brand: 'Life Brand Oral Wound Cleanser'.[24] Also, Jean Coutu and Rexall has their own house brand versions.
Drug facts
- Active ingredient: Sodium perborate monohydrate1.2 g
- Inactive ingredients: L-sodium saccharin, flavors
- Purpose: Oral wound cleanser
- Normal use: Use up to 4 times daily, after meals and before bedtime or as directed by a dentist or physician
See also
- Amosan
- Sodium percarbonate
- Persil
References
- ^ ISBN 978-3527306732.
- ^
- ^ ISBN 0-471-93620-0
- ISBN 978-0-08-037941-8.
- .
- ^ "Sodium Perborate REACH Consortium" (PDF). Archived from the original (PDF) on 2014-04-26. Retrieved 2012-06-07.
- ^ Paul, Mollard (12 June 1962). "US3038842A Process of making sodium perborate by electrolysis". Google Patents.
- ISBN 978-0-471-93623-7, retrieved 2021-01-18
- PMID 379049.
- ^
- ^ "Two sachets of Bocasan mouthwash powder, supplied by Knox la < CultureGrid".
- ^ Medicines: The Comprehensive Guide edited by Dr. Ian Morton, Judith M. Hall. Royal Society of Medicine. Bloomsbury Publishing, London, 2002. Pg 118
- ^ "Home ⋆ Bik & Bik Online Pharmacy".
- PMID 379049.
- PMID 9846796.
- PMID 10674956.
- ^ "Home". amosan.ca.
- ^ Federal register
- user-generated source]
- ^ "Amosan Oral Wound Cleanser Powder". Amazon.com. Amazon.
- ^ "Bocasan/Amosan". Mouthulcers.org.
- ^ "Life Brand Oral Wound Cleanser Mouthwash 1.7g x 20 Sachets SKU 057800802228". Shopper Drug Mart / Pharmaprix. Archived from the original on 2016-03-04. Retrieved 2014-09-25.