The antimicrobial properties of ethylparaben are considerably
reduced in the presence of nonionic surfactants as a result of
micellization. Absorption of ethylparaben by plastics has not been
reported, although it appears probable given the behavior of other
parabens. Ethylparaben is coabsorbed on silica in the presence of
ethoxylated phenols. Yellow iron oxide, ultramarine blue, and
aluminum silicate extensively absorb ethylparaben in simple
aqueous systems, thus reducing preservative efficacy.
Ethylparaben is discolored in the presence of iron and is subject
to hydrolysis by weak alkalis and strong acids.
white crystalline powder
Accepted as a food additive in Europe. Included in the FDA Inactive
Ingredients Database (oral, otic, and topical preparations). Included
in nonparenteral medicines licensed in the UK. Included in the
Canadian List of Acceptable Non-medicinal Ingredients.
Ethylparaben is widely used as an antimicrobial preservative in
cosmetics,food products, and pharmaceutical formulations.
It may be used either alone or in combination with other paraben
esters or with other antimicrobial agents. In cosmetics it is one of the
most frequently used preservatives.
The parabens are effective over a wide pH range and have a
broad spectrum of antimicrobial activity, although they are most
effective against yeasts and molds.
Owing to the poor solubility of the parabens, paraben salts,
particularly the sodium salt, are frequently used. However, this may
cause the pH of poorly buffered formulations to become more
Ethylparaben and other parabens are widely used as antimicrobial
preservatives in cosmetics, food products, and oral and topical
Systemically, no adverse reactions to parabens have been
reported, although they have been associated with hypersensitivity
reactions. Parabens, in vivo, have also been reported to exhibit
estrogenic responses in fish.(10) The WHO has set an estimated total
acceptable daily intake for methyl-, ethyl-, and propylparabens at
up to 10 mg/kg body-weight.LD50 (mouse, IP): 0.52 g/kg
LD50 (mouse, oral): 3.0 g/kg
Ethylparaben occurs as a white, odorless or almost odorless,
Ethylparaben is prepared by the esterification of p-hydroxybenzoic
acid with ethanol (95%).
This substance is one of the parabens family. Parabens are esters formed by p-hydroxybenzoic acid
and an alcohol. They are largely used as biocides in
cosmetics and toiletries, medicaments, or food. They
have synergistic power with other biocides. Parabens
can induce allergic contact dermatitis, mainly in
chronic dermatitis and wounded skin.
The Journal of Organic Chemistry, 39, p. 3343, 1974 DOI: 10.1021/jo00937a007
Aqueous ethylparaben solutions at pH 3–6 can be sterilized by
autoclaving, without decomposition. At pH 3–6, aqueous
solutions are stable (less than 10% decomposition) for up to about
4 years at room temperature, while solutions at pH 8 or above are
subject to rapid hydrolysis (10% or more after about 60 days at
Ethylparaben should be stored in a well-closed container in a
cool, dry place.
Preservative for pharmaceuticals.