Methylparaben
What it does
Antimicrobial preservative.
How it's made
Synthesised paraben ester.
Methylparaben (methyl para-hydroxybenzoate) is a preservative from the "paraben" family, used to protect against moulds and yeasts in a range of foods, and widely in cosmetics and medicines. It works across a broader range of acidity than the benzoates and sorbates.
It is made by chemical synthesis, reacting para-hydroxybenzoic acid with methanol (methyl alcohol) in an esterification, which joins them to form the methyl ester and water. Para-hydroxybenzoic acid itself is produced from phenol-derived feedstocks.
The ester is purified by crystallisation into a white powder. Parabens are effective preservatives at low levels and are stable over a wide pH range, which is why they are used where benzoates would not work as well; their food use is regulated and limited to particular products and levels.
Possible reactions
Possible allergic reactions; parabens are hormone-disruption suspects (debated).