Imidazolidinyl Urea

Medium Concern

Formaldehyde Releaser

Also known as

imidazolidinyl urea

The concern

Formaldehyde-releasing preservative. EWG moderate-to-high concern for cancer and allergies. Common cause of contact dermatitis.

What to look for on labels

This ingredient may appear under any of the following names or codes on product labels:

Read the full evidence directly from the authoritative source.

Hair straightening products, some shampoos and conditioners

DMDM Hydantoin

Preservative that slowly releases formaldehyde (an IARC Group 1 carcinogen) as it breaks down.

Quaternium-15

One of the most common formaldehyde-releasing preservatives.

Data sourced from IARC, FDA, EFSA, WHO and EWG public data. For informational purposes only. This does not constitute medical or legal advice.