The Lab
Specimen No. 0013
AvoidSyntheticpreservative

Formaldehyde-Releasing Preservatives

dmdm hydantoin · quaternium-15 · imidazolidinyl urea

A class of preservatives that slowly release formaldehyde — a known human carcinogen (IARC Group 1) — into cosmetic formulas.

high confidence
Researched April 18, 2026

Concerns

  • Formaldehyde is IARC Group 1 carcinogen
  • Skin sensitization and allergic contact dermatitis
  • Respiratory irritant with repeated exposure
  • California Prop 65 listed

Regulatory flags

  • Formaldehyde: IARC Group 1 carcinogen
  • EU banned from cosmetics at >0.1% formaldehyde release
  • EU requires 'contains formaldehyde' label if >0.05%

Commonly found in

ShampooConditionerBody washBaby productsHair straighteners

Research disclaimer: This rating is based on available peer-reviewed research and regulatory assessments at the time of publication. It is not medical advice. Consult a qualified professional for personal health or skin concerns.

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Safer swaps · Research references

Based Bodyworks

BASED Body Wash

90/100

Sulfate-free, fragrance-free body wash with no hormone-disrupting ingredients.

Why it's cleaner

No flagged ingredients in our current review; key ingredients include Coco glucoside, Aloe vera, Glycerin.

Coco glucosideAloe veraGlycerinTea tree
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LabelCleared verdict badge: Formaldehyde-Releasing Preservatives — Avoid
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