Butylparaben is a chemical compound, butyl ester of p-hydroxybenzoic acid.

It appears as a fine white powder.

What it is used for and where

It is used as a preservative against:

• preservative
• antibacterial
• anti-mould
• fungicide

Found in :

• Shaving creams
• Moisturisers
• Shampoo

Like all members of the paraben family, it can give rise to allergies and DNA damage.

In a 2020 study, six parabens were compared in a cytotoxicity test with two in vitro toxicological methods and the results classified Butylparaben as positive (1).

Parabens

Parabens are preservative chemical compounds that have been the subject of attention in the scientific literature as possible endocrine disruptors (particularly propylparaben and butylparaben), i.e. with the possibility of damaging the hormone-producing glands in our bodies, particularly in the breasts. The 2004 study by Darbre et al. showed that parabens remain in our bodies as intact esters (2). Following this study, some of the scientific literature in 2005 and 2006 cast doubt on Darbre's conclusions and claimed they were limited. However, both the US FDA and the European SCCP authorised in 2006 the use of a single paraben in cosmetic products at a concentration of 0.4% and the use of total parabens at a concentration of 0.8% (3). However, there is no shortage of studies that consider the restrictions unnecessary: M. G. Kirchhof et al. in 2013 found that parabens are among the safest and most well-tolerated preservatives and that current data do not support drastic regulations or personal exposure restrictions (4). Darbre in 2014 published a further study in which he showed how parabens can cause DNA damage (5).

Butylparaben studies

Typical optimal commercial product characteristics Butylparaben  

Appearance	White fine powder
Boiling Point	309.2±15.0 °C at 760 mmHg
Melting Point	67-70 °C
Flash Point	129.2±13.2°C
Density	1.1±0.1 g/cm3
Water Solubility	<0.1 g/100 mL at 17 ºC
Loss on drying	≤2.0%
Impurity	≤0.1%
Heavy metals	≤10 ppm
Residue on ignition	≤0.1%
Vapour Pressure	0.0±0.7 mmHg at 25°C
Index of Refraction	1.526
PSA	46.53000
LogP	3.46
Safety

• Molecular Formula    C₁₁H₁₄O₃
• Molecular Weight   194.23 g/mol
• Exact Mass   194.094299
• UNII: 3QPI1U3FV8
• CAS: 94-26-8  8068-49-3  1350551-41-5
• EC Number: 202-318-7
• DSSTox Substance ID  DTXSID3020209
• IUPAC  butyl 4-hydroxybenzoate
• InChI=1S/C11H14O3/c1-2-3-8-14-11(13)9-4-6-10(12)7-5-9/h4-7,12H,2-3,8H2,1H3  
• InChl Key      QFOHBWFCKVYLES-UHFFFAOYSA-N
• SMILES   CCCCOC(=O)C1=CC=C(C=C1)O
• FEMA Number: 2203
• MDL number MFCD00016478
• Beilstein Registry Number 1103741
• NSC   759303     8475
• JECFA    870

Synonyms: 

• Butyl 4-hydroxybenzoate
• Butyl paraben
• Butyl p-hydroxybenzoate
• Nipabutyl
• Tegosept Butyl
• Aseptoform butyl
• Preserval B
• Butyl parahydroxybenzoate
• Butyl-Parasept
• 4-(Butoxycarbonyl)phenol
• n-Butyl parahydroxybenzoate
• Tegosept B
• Butoben
• Butyl chemosept
• Butyl parasept
• Butyl tegosept
• Butyl butex
• Solbrol B
• n-Butyl p-hydroxybenzoate
• Benzoic acid, 4-hydroxy-, butyl ester
• n-Butyl hydroxybenzoate
• n-Butyl-p-hydroxybenzoate
• 4-Hydroxybenzoic acid butyl ester
• Butylparaben [USAN]
• butyl-p-hydroxybenzoate

References_______________________________________________

(1) Chrz J, Hošíková B, Svobodová L, Očadlíková D, Kolářová H, Dvořáková M, Kejlová K, Malina L, Jírová G, Vlková A, Mannerström M. Comparison of methods used for evaluation of mutagenicity/genotoxicity of model chemicals - parabens. Physiol Res. 2020 Dec 31;69(Suppl 4):S661-S679. doi: 10.33549/physiolres.934615. 

(2) Darbre PD, Aljarrah A, Miller WR, Coldham NG, Sauer MJ, Pope GS. Concentrations of parabens in human breast tumours. J Appl Toxicol. 2004 Jan-Feb;24(1):5-13. doi: 10.1002/jat.958.

(3) https://www.fda.gov/cosmetics/cosmetic-ingredients/parabens-cosmetics

Cosmetic Ingredient Review Expert Panel. Final amended report on the safety assessment of Methylparaben, Ethylparaben, Propylparaben, Isopropylparaben, Butylparaben, Isobutylparaben, and Benzylparaben as used in cosmetic products. Int J Toxicol. 2008;27(Suppl 4):1-82.

(4) Kirchhof MG, de Gannes GC. The health controversies of parabens. Skin Therapy Lett. 2013 Feb;18(2):5-7.

(5) Darbre PD, Harvey PW. Parabens can enable hallmarks and characteristics of cancer in human breast epithelial cells: a review of the literature with reference to new exposure data and regulatory status. J Appl Toxicol. 2014 Sep;34(9):925-38. doi: 10.1002/jat.3027.