sodium perborate

Unlike sodium percarbonate, the peroxyborates are not adducts of hydrogen peroxide.{{Greenwood&Earnshaw}} Rather, they contain a peroxyborate anion {{chem2|[(B(OH)2OO)2](2-)}}, which consists of a cyclic {{chem2|\sB\sO\sO\sB\sO\sO\s}} core with a pair of hydroxy groups bonded to each boron atom. The ring adopts a chair conformation.{{cite journal |author1=Carrondo, M. A. A. F. de C. T. |author2=Skapski, A. C. |journal= Acta Crystallogr B|volume=34 |page= 3551 |title= Refinement of the X-ray Crystal Structure of the Industrial Bleaching Agent Disodium Tetrahydroxo-di-μ-peroxo-diborate Hexahydrate, Na₂[B₂(O₂)₂(OH)₄]·6H₂O |year= 1978 |doi= 10.1107/S0567740878011565}} The hexahydrate has the formula {{chem2|Na2H4B2O8*6H2O}}, that is, {{chem2|Na2H16B2O14}} or {{chem2|NaH8BO7}}.{{cite book |doi=10.1002/14356007.a04_263.pub2 |chapter=Boric Oxide, Boric Acid, and Borates |title=Ullmann's Encyclopedia of Industrial Chemistry |date=2015 |last1=Schubert |first1=David M. |pages=1–32 |isbn=978-3-527-30385-4 }}

The anhydrous compound is commonly but incorrectly called a "monohydrate" with the historical but misleading formula {{chem2|NaBO3*H2O}}. Instead, a more descriptive formula is {{chem2|Na2[(HO)2B]2(O2)2}}. Likewise, the hexahydrate is usually called "tetrahydrate" and formulated as {{chem2|NaBO3*4H2O}}. Both forms are white, odorless, water-soluble solids. The "monohydrate" and the "tetrahydrate" are the commercially important forms.

A true tetrahydrate {{chem2|Na2H4B2O8*4H2O}}, traditionally known as the "trihydrate", is also known but has no industrial significance. There is a CAS number for each of the three traditional "hydrates", the three "peroxyborate" versions of each (interpreted as a hydrogen peroxide adduct) and the poorly-defined "anhydrate" {{chem2|NaBO3}}, a total of seven.

Sodium perborate hydrolyzes (i.e. breaks down in contact with water), producing hydrogen peroxide and borate:

:{{chem2|(HO)2B]2(OO)2)(2-) + 2 H2O <-> 2 [(HO)2B(OH)(OOH)]-}}

The resulting hydroperoxide then enter in equilibrium with boric acid {{chem2|B(OH)3}}, hydrogen peroxide {{chem2|H2O2}}, the hydroperoxyl anion {{chem2|-OOH}}, and the tetrahydroxyborate anion {{chem2|[B(OH)4]-}}:

:{{chem2|[B(OH)3(OOH)]- ⇌ B(OH)3 + HO2-}}

:{{chem2|B(OH)3 + HO2- + H2O ⇌ [B(OH)4]- + H2O2}}

As the concentration of the solution increases, other peroxoborate species become significant. With excess {{chem2|H2O2}}, the anions {{chem2|[B(OH)2(OOH)2]-}}, {{chem2|[B(OH)(OOH)3]-}}, and eventually {{chem2|[B(OOH)4]-}} appear. At high borate concentrations, the sodium perborate with dimeric anion crystallizes out, due to its relatively low solubility.

The "monohydrate" form dissolves faster than the "tetrahydrate" and has higher heat stability; it is prepared by heating the "tetrahydrate". The commercial "anhydrate", or Oxoborate, is prepared by further heating of "monohydrate" and actually consists of sodium borate and boron–oxygen radical.

Sodium perborate is manufactured by reaction of borax {{chem2|Na2B4O7}} and sodium hydroxide NaOH to give sodium metaborate {{chem2|NaBO2}}, which is then reacted with hydrogen peroxide to give hydrated sodium perborate:{{cite web|url=http://www.perborates.eu/docs/PBS_SIP1010.pdf|title=Sodium Perborate REACH Consortium|accessdate=2012-06-07|archive-date=2014-04-26|archive-url=https://web.archive.org/web/20140426234530/http://www.perborates.eu/docs/PBS_SIP1010.pdf|url-status=dead}}

:{{chem2|Na2B4O7 + 2 NaOH → 4 NaBO2 + H2O}}

:{{chem2|2 NaBO2 + 2 H2O2 → Na2B2O4(OH)4}}

A surfactant may be added to control crystal size.J. Dugua and B.Simon (1978): "Crystallization of sodium perborate from aqueous solutions: I. Nucleation rates in pure solution and in presence of a surfactant". Journal of Crystal Growth, volume 44, issue 3, pages 265-279.{{doi|10.1016/0022-0248(78)90025-8}}J. Dugua and B.Simon (1978): "Crystallization of sodium perborate from aqueous solutions: II. Growth kinetics of different faces in pure solution and in the presence of a surfactant". Journal of Crystal Growth, volume 44, issue 3, pages 280-286.{{doi|10.1016/0022-0248(78)90026-X}}

It may also be produced in the electrolysis of an aqueous 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{{nbsp}}°C.{{cite web |last1=Paul |first1=Mollard |title=US3038842A Process of making sodium perborate by electrolysis |url=https://patents.google.com/patent/US3038842A/en |website=Google Patents |date=12 June 1962}}

Sodium perborate serves as a stable source of active oxygen in many detergents, laundry detergents, cleaning products, and laundry bleaches. It is a less aggressive bleach than sodium hypochlorite and other chlorine-based bleaches, causing less degradation to dyes and textiles. Sodium perborate releases oxygen rapidly at temperatures greater than 60 °C. Addition of the activator, typically tetraacetylethylenediamine (TAED), makes it active at lower temperatures (40–60 °C).

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.{{cn|date=September 2023}}

Sodium perborate monohydrate is quickly hydrolyzed into hydrogen peroxide and borate on contact with water. A 1979 double-blind crossover study{{cite journal | pmid = 379049 | volume=6 | issue=2 | title=Effect of hydrogen peroxide on developing plaque and gingivitis in man. | date=Apr 1979 | journal=J Clin Periodontol | pages=115–30 | doi=10.1111/j.1600-051x.1979.tb02190.x| last1=Wennstrom | first1=Jan | last2=Lindhe | first2=Jan }} 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 tooth bleaching formulas for non vital root treated teeth. The compound is inserted in the root canal and left in place for an extended period of time to allow it to diffuse into the tooth and bleach stains from the inside out. However, this use has been banned in the European Union.

Sodium perborate is also used as an oxidizing reagent in organic synthesis. For example, it converts thioethers into sulfoxides and sulfones.{{Citation|last1=McKillop|first1=Alexander|title=Sodium Perborate|date=2008-09-15|url=http://doi.wiley.com/10.1002/047084289X.rs094.pub2|encyclopedia=Encyclopedia of Reagents for Organic Synthesis|pages=rs094.pub2|editor-last=John Wiley & Sons, Ltd|place=Chichester, UK|publisher=John Wiley & Sons, Ltd|language=en|doi=10.1002/047084289x.rs094.pub2|isbn=978-0-471-93623-7|access-date=2021-01-18|last2=Kabalka|first2=George W.|last3=Reddy|first3=Marepally Srinivasa|url-access=subscription}} Another use of sodium perborate in organic synthesis is as a convenient alternative to Hydrogen peroxide, for example in the 2 step conversion of an aryl halide to a phenol (the first step is a Miyaura borylation).[https://www.commonorganicchemistry.com/Patents/BMS/WO2016010950.pdf#page=223.pdf Spirocycloheptanes as inhibitors of rock]

File:Oxidation of Boronate in a 2 step synthesis of a phenol.svg

In the European Union, sodium perborate, like most perborates, 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.{{Cite web |title=Substance Information - ECHA |url=https://echa.europa.eu/substance-information/-/substanceinfo/100.035.597 |access-date=2025-01-22 |website=echa.europa.eu |language=en-GB}}Nature Inc. (2015): "Chemical used in beauty salon teeth whitening banned by EU". BDJ Team, volume 2, article 15075, 26 June 2015. {{doi|10.1038/bdjteam.2015.75}}

Bocasan was an oral wound cleanser manufactured in the United Kingdom by Knox Laboratories Ltd of London from 1960–1975,{{cite web|url=http://www.culturegrid.org.uk/static/showResource/3051671|title=Two sachets of Bocasan mouthwash powder, supplied by Knox la < CultureGrid}} before being rebranded as an Oral-B product

Medicines: The Comprehensive Guide edited by Dr. Ian Morton, Judith M. Hall. Royal Society of Medicine. Bloomsbury Publishing, London, 2002. Pg 118

File:Bocasan dental rinse front.JPG

File:Bocasan dental rinse back.JPG

Production of Bocasan appears to have ceased by 2003. A similar product, Amosan was available for a period before also ceasing production in 2010. As of 2013, a Dutch pharmacy offers the same formulation under the name Bikosan{{cite web|url=https://www.bik-bik.com/info/14/bikosan-replaces-bocasan|title = Home ⋆ Bik & Bik Online Pharmacy}}

It was used to aid treatment, in adults or children over 5 years old, of periodontal conditions such as canker sores, denture irritation, orthodontic irritation, or after dental procedures.

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{{cite journal | pmid = 379049 | volume=6 | issue=2 | title=Effect of hydrogen peroxide on developing plaque and gingivitis in man | date=April 1979 | journal=Journal of Clinical Periodontology | pages=115–30 | doi=10.1111/j.1600-051x.1979.tb02190.x| last1=Wennstrom | first1=Jan | last2=Lindhe | first2=Jan }} 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.{{cite journal |last1=Dona |first1=BL |last2=Gründemann |first2=LJ |last3=Steinfort |first3=J |last4=Timmerman |first4=MF |last5=van der Weijden |first5=GA |title=The inhibitory effect of combining chlorhexidine and hydrogen peroxide on 3-day plaque accumulation. |journal=Journal of Clinical Periodontology |date=November 1998 |volume=25 |issue=11 Pt 1 |pages=879–83 |doi=10.1111/j.1600-051x.1998.tb02385.x |pmid=9846796}} A further study (n=28) shows that Bocasan reduces the staining associated with chlorhexidine.{{cite journal |last1=Gründemann |first1=LJ |last2=Timmerman |first2=MF |last3=Ijzerman |first3=Y |last4=van der Weijden |first4=GA |last5=van der Weijden |first5=GA |title=Stain, plaque and gingivitis reduction by combining chlorhexidine and peroxyborate. |journal=Journal of Clinical Periodontology |date=January 2000 |volume=27 |issue=1 |pages=9–15 |doi=10.1034/j.1600-051x.2000.027001009.x |pmid=10674956}}

• 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

File:Amosan Oral Antiseptic Rinse 2014 - Product Photo.jpg

Amosan{{cite web |url=http://www.amosan.ca/ |title=Home |website=amosan.ca}} is an oral antiseptic rinse. It contains 68.635% sodium perborate monohydrate by weight. Sold as a powder customarily packaged in 1.7g envelopes, it reconstitution with warm water, after which it is used as a mouth rinse. It is used to aid in the prevention of, as well as speed the recovery from canker sores, denture irritation, orthodontic irritation, and oral injuries or after dental procedures.

Amosan was originally made by Oral-B; a mention of the powder appeared in the February 6, 1970 Federal Register.[https://www.govinfo.gov/content/pkg/FR-1970-02-06/pdf/FR-1970-02-06.pdf Federal register] 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".Nature Inc. (2015): "Chemical used in beauty salon teeth whitening banned by EU". BDJ Team, volume 2, article 15075, 26 June 2015. {{doi|10.1038/bdjteam.2015.75}}

Vintage Brands Limited began manufacturing and selling Amosan Oral Antiseptic Rinse in 2014 because many consumers were disappointed that it was no longer available.[https://www.facebook.com/AmosanOralProducts Amosan Oral Products] Facebook {{User-generated source|certain=yes|date=March 2022}} Product review pages on Amazon{{cite web |url= https://www.amazon.com/Amosan-Oral-Wound-Cleanser-Powder/dp/B000GGHT52 |title= Amosan Oral Wound Cleanser Powder |publisher= Amazon |website= Amazon.com}} and public comment forums elsewhere{{cite web|url=http://www.mouthulcers.org/messages.php?thread=1463|title=Bocasan/Amosan|publisher=Mouthulcers.org}} 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'.{{cite web |url=http://www1.shoppersdrugmart.ca/en/health-and-pharmacy/personal-care/oral-lip-care/details/057800802228 |access-date=2014-09-25 |archive-url=https://web.archive.org/web/20160304040826/http://www1.shoppersdrugmart.ca/en/health-and-pharmacy/personal-care/oral-lip-care/details/057800802228 |archive-date=2016-03-04 |url-status=dead |title= Life Brand Oral Wound Cleanser Mouthwash 1.7g x 20 Sachets SKU 057800802228 |publisher= Shopper Drug Mart / Pharmaprix }} Also, Jean Coutu and Rexall has their own house brand versions.

• Active ingredient: Sodium perborate monohydrate 1.2 g
• Inactive ingredients: L-Tartaric acid, 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

• Amosan
• Sodium percarbonate
• Persil

{{reflist}}

{{notelist}}

• [https://web.archive.org/web/20051123101005/http://www.borax.com/detergents/bleaching.html Borax Detergent Book: Bleaching]
• [https://web.archive.org/web/20060209040519/http://www.npi.gov.au/database/substance-info/profiles/15.html National Pollutant Inventory - Boron and compounds]
• [http://history.evonik.com/sites/geschichte/en/chemicals/inventions/degussa/sodium-perborate/Pages/default.aspx Sodium perborate history, image] {{Webarchive|url=https://web.archive.org/web/20110407065711/http://history.evonik.com/sites/geschichte/en/chemicals/inventions/degussa/sodium-perborate/pages/default.aspx |date=2011-04-07 }}
• [https://www.organic-chemistry.org/chemicals/oxidations/sodiumperborate.shtm Sodium perborate in organic synthesis]

{{Stomatological preparations}}

{{sodium compounds}}

{{Borates}}

Category:Sodium compounds

Category:Borates

Category:Peroxides

Category:Cleaning product components

Category:Antiseptics

Category:Bleaches

Category:Oxidizing agents