In 2016, dermatologists in Finland suspected contact allergy in several patients using moisturizers under the trade name Apobase®. Following a formulation change, Phenostat™, which is a mixture of phenoxyethanol, caprylhydroxamic acid, and methylpropanediol, was used as a preservative in Apobase® moisturizers in Finland.
Results: The patch tests showed positive reactions to the new Apobase® formulas, Phenostat™, and caprylhydroxamic acid or its potassium salt, but not to the old Apobase® formulas, methylpropanediol, or phenoxyethanol.
Conclusions: We found a new contact allergen, caprylhydroxyamic acid, which caused an epidemic of allergic contact dermatitis in patients using moisturizers containing this preservative. Whether the sensitizing capacity of caprylhydroxamic acid depends on the other chemicals used in Apobase® moisturizers needs further investigation.
You don’t want to be in this publication: caprylhydroxamic acid
"This is the worse advice I have ever seen. If your skin starts getting worse, stop doing what you are doing, and certainly don’t keep harming in your skin in additional ways. In this case, the problem seems to be caprylhydroxamic acid, a new ingredients used as preservative in this anti-paraben craze, that has produced an epidemic of allergic contact dermatitis." Dr. Hannah Sivak, Skin Care Scientist | February 21, 2019