Triclosan

What it is

Triclosan is a chlorinated phenol that was used for decades in antibacterial soaps, toothpastes and deodorants. Two things changed its standing: evidence that it interferes with thyroid hormone signalling in animals, and concern that widespread consumer use might contribute to bacterial resistance. The EU responded not with a ban but with a closed list: triclosan is permitted only in specified product categories, and face masks are not among them.

What it does well

• Genuinely effective against plaque bacteria in toothpaste

  Its best-evidenced use is oral care, where clinical trials showed reductions in plaque and gingivitis. That is a different context from leave-on skincare.

  Strong evidence

Worth knowing

• Interferes with thyroid hormone signalling in animal studies

  A 2023 review concluded triclosan impairs thyroid homeostasis and has been linked in the literature to neurodevelopmental, metabolic and other effects. The SCCS assessed it as an endocrine-disruption candidate in 2022 and found the permitted uses broadly acceptable, with reservations for children's mouthwashes and toothpastes.

  Matters most toPeople with thyroid conditions and parents choosing children's oral-care products.

• Contributes to environmental load and possible resistance selection

  Triclosan is persistent in wastewater and is detectable in surface waters and human urine. Concern about selecting for resistant bacteria was a major driver of restrictions in several jurisdictions.

  Matters most toPeople weighing environmental impact alongside skin safety.

• Not permitted as a general-purpose preservative

  EU rules confine it to a defined list of product types. Its presence in a leave-on face mask sold in the EU would be non-compliant.

  Matters most toPeople buying imported personal-care products.

Where the EU stands

Sources (2)

Every link goes to the original: a journal, a PubMed record or an EU document.

1. [1]
   Safety of Triclocarban and Triclosan as substances with potential endocrine disrupting properties in cosmetic products (SCCS/1643/22)

   SCCS (Scientific Committee on Consumer Safety), European Commission · 2022

   The SCCS considered triclosan safe at the concentrations set out in Annex V with specific exceptions, and flagged safety concerns for some uses such as children's mouthwashes and toothpastes.

2. [2]
   Comprehensive insight into triclosan-from widespread occurrence to health outcomes

   Environmental Science and Pollution Research International · 2023

   This review concluded that triclosan impairs thyroid homeostasis and has been associated in the literature with neurodevelopmental impairment, metabolic disorders, cardiotoxicity and increased cancer risk.