- Bronopol
Chembox new
Name = Bronopol
ImageFile = Bronopol.png
ImageSize = 200px
ImageName = Bronopol
IUPACName = 2-bromo-2-nitropropane-1,3-diol
Section1 = Chembox Identifiers
CASNo = 52-51-7
SMILES = OCC( [N+] ( [O-] )=O)(Br)CO
Section2 = Chembox Properties
Formula = C3H6BrNO4
MolarMass = 199.989 g/mol
Appearance = Crystals / crystalline powder, varying from
white to pale yellow depending on the grade
Density =
MeltingPt = 130 °C
BoilingPt = 140 °C (decomposes)Bronopol (INN) is a highly active
antimicrobial chemical compound whosechemical formula is 2-bromo-2-nitropropane-1,3-diol.Bronopol was invented by The Boots Company PLC,
Nottingham, England in the early 1960s and first applications were as apreservative forpharmaceutical s. Bronopol's lowmammal iantoxicity (at in-use levels) and exceptional activity againstbacteria (especially the troublesomeGram-negative species) ensured that it became popular as a preservative in many consumer products such asshampoo s andcosmetics .Bronopol was subsequently taken up as an effective antimicrobial in many industrial environments such as
paper mill s,oil exploration and production facilities, as well as cooling water disinfection plants.World production soared from the tens of
ton nes in the late 1970s to current estimates in excess of 5,000 tonnes. This is quite something considering the effective use-concentration which can be as low as 0.0025% (25 parts per million). Manufacturing today is the business of low cost producers, mainly inChina .Pharmaceutical products containing Bronopol are registered in a number of countries and Bronopol is the subject of a specific
monograph in theBritish Pharmacopoeia 1998.Applications
Today, Bronopol is used in consumer products as an effective preservative agent, as well as a wide variety of industrial applications (almost any industrial water system is a potential environment for bacterial growth, leading to
slime andcorrosion problems - in many of these systems Bronopol can be a highly effective treatment).It is also used as a substitute for
Formaldehyde inchemical toilet s.The use of Bronopol in
personal care products (cosmetics ,toiletries ) has declined since the late 1980s due to the recognized potential fornitrosamine formation.The Nitrosamine Problem
Although fairly ubiquitous in our diet and the environment, and even produced within the
stomach from various foodstuffs, many nitrosamines are known or suspectcarcinogen s and therefore should be avoided in manufactured goods.Nitrosamines are relatively easily produced from secondary
amines andamides in the presence ofnitrite ion s (this is why they are formed in-vivo from foodstuffs).While Bronopol is not in itself a nitrosating agent, under conditions where it decomposes "(
alkaline solution and/or elevated temperatures)" it can liberate nitrite and low levels of formaldehyde and these decomposition products can react with any contaminant secondary amines or amides in a personal care formulation to produce significant levels of nitrosamines (due to the toxicity of thes substances, the term 'significant' means levels as low as 10s of parts per billion).Manufacturers of personal care products are therefore instructed by regulatory authorities to 'avoid the formation of nitrosamines' which might mean removing amines or amides from the formulation, removing Bronopol from a formulation, or using nitrosamine inhibitors.
Physical and chemical properties
Appearance
Bronopol is supplied as
crystal s or crystalline powder, which may vary from white to pale yellow in colour depending on the grade of material being offered.Melting point
As a pure material, Bronopol has a
melting point of about 130°C. However due to its polymorphic characteristics, Bronopol undergoes alattice rearrangement at 100 to 105°C and this can often be wrongly interpreted as the melting point.At temperatures above 140°C Bronopol will decompose
exothermic ally releasingHydrogen bromide and oxides ofNitrogen .olubility
Bronopol is readily soluble in water although the dissolution process is
endothermic . Solutions containing up to 28% w/v are possible atambient temperature .Bronopol is poorly soluble in non-polar
solvent s but shows a high affinity for polar organic solvents.Partition coefficient
Study of the solubility data clearly shows that Bronopol has a high affinity for polar rather than non-polar environments. In two phase systems, Bronopol partitions preferentially into the polar (usually aqueous) phase.
tability in aqueous solution
In aqueous solutions, Bronopol is most stable when the
pH of the system is on theacid side of neutral. Temperature also has a significant effect on stability in alkaline systems.Degradation
When conditions are such that Bronopol decomposes in aqueous solution, very low levels of formaldehyde are produced. "Liberated formaldehyde is not responsible for the biological activity associated with Bronopol".
Amongst other decomposition products detected after Bronopol breakdown are, bromide ion, nitrite ion, Bromonitroethanol and 2-Hydroxymethyl-2-nitropropane-1,3-diol.
ee also
*
Bronidox References
* [http://www.ascc.com.au/position/position/nitrosamines_in_cosmetics.htm Nitrosamines in Cosmetics, Toiletries and Personal Care Products] The Australian Society of Cosmetic Chemists
* [http://www.verichem.com/uploads/MSDS%20Vericide%20Bronopol.pdf Material Safety Data Sheet for Bronopol]External links
* http://www.furrental.com/pages/fj/bronopol.pdf
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