Susan Barclay-Nichols

Iodopropynyl butylcarbamate (IPBC) is a non-formaldehyde releasing chemical based on iodine. It is effective against fungus and bacteria and can be combined with diazolidinyl urea or parabens to create a broad spectrum preservative. The Cosmetics Ingredient Review Panel notes it is safe to use at levels equal to or below 0.1% and the EU allows...

Phenoxyethanol is a phenolic compound with an alcohol functional group that we find in quite a few preservatives. It is not a formaldehyde releaser. It has good activity* against Gram positive and Gram negative bacteria as well as yeast, and is generally paired up with another preservative – a quaternium, benzoic acid, or parabens to...

Imidiazolidinyl urea is one of the most common preservatives, found as Germall 115 (a powder). Created through a chemical reaction of allantoin and formaldehyde in the presence of a sodium hydroxide solution, it’s then neutralized with hydrochloric acid and evaporated. It’s a good anti-bacterial preservative that isn’t great with fungus, so it is generally combined...

Yesterday we took a look at organic acids, including benzoic acid. This is the category under which parabens fall, as they are para-hydroxybenzoic acids. There are five parabens we find in cosmetic products – methylparaben, ethylparaben, propylparaben, butylparaben, and benzylparaben – and two isomers – isopropylparaben and isobutylparaben – and the position of the functional...