The Lab
Specimen No. 0198
AvoidSyntheticcosmetic preservative

Methylisothiazolinone

CAS 2682-20-4 · MIT · MI · Methylisothiazolinone

A synthetic preservative that became one of the most common contact allergens of the last decade, driving a documented epidemic of allergic contact dermatitis.

high confidence
Researched July 7, 2026

Concerns

  • Methylisothiazolinone drove a global epidemic of allergic contact dermatitis during 2010 to 2015, reaching its peak in 2013 and 2014 (Ozkaya 2020, PMID 32691417)
  • It is a frequent contact allergen; after being regulated in the European Union a significant drop in cases was seen, whereas high rates continued in regions such as North America (Johansen 2022, PMID 35183605)

Regulatory flags

  • IARC Class: NL
  • EDC Status: Not established
  • Regulatory: US: permitted, high sensitization rates persist; EU: restricted following the ACD epidemic
  • Evidence Grade: A

Commonly found in

Rinse-off shampoo and conditionerWet wipesLiquid hand soapWater-based paint

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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