At a glance
| Chemical family | Chlorinated phenolic antimicrobial — bacteriostatic at low concentrations, bactericidal at higher; inhibits bacterial fatty acid synthesis via the FabI enzyme; in commercial use since 1972 |
| CAS number | 3380-34-5; also known as Irgasan DP-300; chemical name 5-chloro-2-(2,4-dichlorophenoxy)phenol |
| Classification | Not formally evaluated by IARC; US FDA Final Rule (September 2016, 21 CFR § 310.545) — banned from OTC consumer antiseptic wash products; FDA-approved for toothpaste at up to 0.3% (gingivitis-prevention indication); EU Cosmetics Regulation Annex V permits at 0.3% in specific cosmetic product types; EPA registered for some antimicrobial uses; biological half-life ~21 hours in humans |
| Where you encounter it | Toothpastes (declining post-2019 Colgate Total reformulation); some specialty cosmetics (declining since 2016); treated textiles (antimicrobial socks, athletic wear, some mattress covers — declining since EU and consumer pressure); some kitchen products with antimicrobial claims (cutting boards, cookware surfaces); healthcare antiseptics (separate FDA category, not subject to 2016 consumer-wash ban) |
| Sleep micro environment relevance | Limited but real — antimicrobial-treated textiles (treated bedding, mattress covers, sleepwear) carry triclosan into direct skin contact during the sleep window. Toothbrush use immediately before bed transfers triclosan from toothpaste to oral mucosa with measurable systemic absorption |
| Activated carbon capture | Not applicable for VOC-phase capture. Triclosan exposure is primarily through skin contact, oral mucosa, and ingestion rather than vapor-phase. The primary residential intervention is product-choice level. Inferred from established triclosan exposure pathways; air capture is not the relevant technology question |
What it is
Triclosan — CAS 3380-34-5, chemical name 5-chloro-2-(2,4-dichlorophenoxy)phenol, sold historically under the trade name Irgasan DP-300 — is a synthetic chlorinated phenolic antimicrobial first developed by Ciba-Geigy in 1965 and commercialized starting in 1972. The mechanism of antimicrobial action is inhibition of the FabI enzyme (enoyl-acyl carrier protein reductase), which catalyzes a critical step in bacterial fatty acid synthesis. At the concentrations used in consumer products (0.1-0.3% by mass), triclosan is bacteriostatic for most target species; at higher industrial concentrations it is bactericidal.
The compound is lipophilic, which drives much of its biological behavior: triclosan is readily absorbed through skin and through oral mucosa, accumulates in body fat at low levels, and partitions to lipid-rich tissues. The biological half-life in humans is approximately 21 hours — substantially faster than the heavy metals (decades) and the persistent organic pollutants (years), but slower than the rapid clearance compounds like the parabens (hours). The faster clearance means body burden tracks closely with current exposure level, and stopping exposure produces measurable reduction in body triclosan within weeks.
Triclosan is environmentally persistent in wastewater and aquatic systems, where it has been documented as a significant pollutant of concern. EPA monitors triclosan as an aquatic toxicant, with concentrations in some treated wastewater effluent exceeding acute aquatic toxicity benchmarks. The environmental concern was an additional factor in the regulatory pressure that led to the 2016 FDA ban.
Where you encounter it
From toothpaste
The largest remaining FDA-approved consumer use category. Triclosan was historically the active ingredient in Colgate Total at 0.3% concentration, approved for gingivitis prevention. Colgate-Palmolive reformulated Colgate Total in 2019 to remove triclosan and replace it with stannous fluoride. Some specialty and older-stock toothpaste formulations may still contain triclosan; current ingredient labels confirm whether a product contains it. Toothpaste use produces measurable oral absorption — Allmyr and colleagues documented the systemic absorption from typical toothbrushing.
From antimicrobial-treated textiles
Some athletic clothing, socks, mattress covers, and bedding products have been marketed with antimicrobial treatments including triclosan. The treatment is applied during fabric finishing and is intended to be durable across multiple wash cycles. EU regulatory action and consumer pressure have driven substantial industry phase-out of triclosan-treated consumer textiles since the mid-2010s, but legacy products remain in circulation, and some current products in the antimicrobial-treated category still use triclosan. For bedroom chemistry, untreated bedding eliminates this pathway entirely.
From historical OTC antimicrobial soaps (banned 2016)
The largest historical consumer exposure category. From the 1980s through September 2016, hand soaps, body washes, bar soaps, foam soaps, and gel soaps marketed as antimicrobial routinely contained triclosan at 0.1-0.45% concentration. The FDA Final Rule of September 6, 2016 (21 CFR § 310.545) banned triclosan and 18 other active antimicrobial ingredients from OTC consumer antiseptic wash products. Regulatory The ban took effect September 6, 2017, and produced a measurable decline in US population urinary triclosan concentrations in subsequent NHANES biomonitoring cycles.
From healthcare antiseptics — separate FDA category
The FDA's 2016 ban applied specifically to consumer antiseptic wash products. Healthcare antiseptics — surgical scrubs, healthcare personnel handwash products, patient preoperative skin preparations — are regulated under a separate FDA OTC monograph framework, and triclosan retains some uses in this category. For bedroom chemistry this is not a direct exposure pathway; it is documented here to clarify the scope of the 2016 ban.
From population biomonitoring data
Calafat, Ye, Wong, Reidy and Needham 2008 in Environmental Health Perspectives reported the foundational CDC NHANES triclosan biomonitoring data from 2003-2004 cycle, detecting triclosan in approximately 75% of US adult urine samples — establishing the population-scale exposure baseline. Peer-reviewed Subsequent NHANES cycles documented the rise toward roughly 92% detection in the mid-2010s and the post-2016 decline as consumer products were reformulated.
What the research says
Thyroid hormone disruption
Multiple animal studies have documented triclosan effects on thyroid hormone homeostasis, with reductions in serum T4 (thyroxine) and T3 (triiodothyronine) at chronic exposures relevant to occupational and high-environmental scenarios. The mechanism appears to involve hepatic enzyme induction increasing thyroid hormone clearance rather than direct effects on the thyroid gland itself. Witorsch 2014 in Critical Reviews in Toxicology reviewed the thyroid endocrine literature with particular attention to the animal-to-human extrapolation question. Peer-reviewed The human evidence at typical residential exposure levels is more limited than the animal evidence at higher chronic doses.
Environmental fate and aquatic toxicity
Dann and Hontela 2011 in Journal of Applied Toxicology reviewed the triclosan environmental exposure, toxicity, and mechanism-of-action literature, providing the consolidated reference for the aquatic-environmental picture and the systemic mammalian toxicology. Peer-reviewed Triclosan is a significant wastewater contaminant: it survives municipal wastewater treatment at non-trivial rates, accumulates in biosolids applied to agricultural land, and reaches surface waters in concentrations that exceed aquatic acute toxicity benchmarks in some receiving water systems. The aquatic ecotoxicity concern is documented; the human health relevance of the environmental persistence is the additional dietary fish and shellfish exposure pathway.
Antimicrobial resistance — the central regulatory driver
The FabI enzyme that triclosan inhibits is the target of the tuberculosis drug isoniazid, and bacterial mutations conferring triclosan resistance can confer cross-resistance to isoniazid and related antibiotics. This mechanistic concern — combined with the widespread, low-concentration, sub-bactericidal consumer use that creates ideal selection pressure for resistance development — was the central public-health rationale for the 2016 FDA ban. The clinical relevance — whether widespread consumer triclosan use has measurably contributed to antibiotic resistance in clinical pathogens — is less precisely characterized than the mechanistic concern, but the mechanistic plausibility was sufficient for the regulatory response.
Endocrine and microbiome effects
Beyond thyroid effects, triclosan has shown estrogenic and androgenic activity at different concentration ranges in various in vitro systems. The broad-spectrum antimicrobial activity also disrupts oral and gut microbiome communities, with documented effects on bacterial diversity in human studies of triclosan-toothpaste users. The microbiome-disruption pathway is increasingly characterized as a separate exposure-of-concern alongside the direct endocrine and resistance pathways.
Regulatory reference values
The ATSDR Public Health Statement for Triclosan provides the regulatory framing on chronic exposure considerations. Regulatory The FDA Consumer Antiseptic Wash Final Rule Q&A guidance provides the regulatory reasoning and implementation details. Regulatory The EU SCCS opinions on triclosan set the European cosmetic-use framework permitting triclosan at 0.3% in specific product types only. Regulatory
What helps reduce exposure
Use regular soap and water for routine hand hygiene. The FDA's 2016 finding was that regular soap and water work as well as antimicrobial soaps for routine non-medical hand hygiene. Antimicrobial soap purchases were already declining before the ban; the regulatory action accelerated the trend.
Choose triclosan-free toothpaste. Major brands have reformulated; check current ingredient labels for "triclosan" in the active ingredients list. Stannous fluoride, sodium fluoride, and similar conventional fluoride-only formulations are widely available and well-characterized.
Avoid antimicrobial-treated textiles for bedding where the antimicrobial claim isn't medically necessary. Untreated cotton, linen, bamboo, and other natural-fiber bedding eliminates the textile exposure pathway entirely. The antimicrobial-treatment marketing is rarely linked to documented clinical benefit for routine consumer use.
For socks and athletic clothing: read labels. "Antimicrobial," "antibacterial," "odor-control," and similar marketing language sometimes signals triclosan or a chemically related antimicrobial treatment. Untreated alternatives are widely available.
For households with members in healthcare settings: be aware of the separate FDA category. Healthcare antiseptics, surgical scrubs, and patient preoperative skin preparations retain some triclosan-containing products. This is largely a workplace exposure scenario rather than a household exposure pathway, but family member take-home contamination on clothing is a documented pattern for various workplace chemistries.
What does NOT help
- "Natural antimicrobial" product claims. Often refer to essential oils (tea tree, thyme, oregano) which have their own toxicological profiles, allergy potential, and limited clinical efficacy evidence for the marketed claims. Replacing one antimicrobial chemistry with another is not automatically safer.
- Assuming all "antibacterial" labels mean triclosan. Since the 2016 ban, the antimicrobial chemistry has diversified. Benzalkonium chloride, chloroxylenol, and other compounds substitute for triclosan in some products. Each has its own evidence base.
- Assuming FDA toothpaste approval means systemic absorption is zero. Allmyr and similar pharmacokinetic studies have documented measurable systemic absorption from typical toothpaste use. The FDA approval reflects a cost-benefit analysis (documented gingivitis benefit + acceptable safety margin), not zero absorption.
- Generic "non-toxic" or "natural" labels. Unregulated marketing terms. Verify the specific ingredient list rather than relying on category-level claims.
Open research questions
- Long-term cumulative effects of low-level triclosan exposure on thyroid function in humans — the animal evidence is established; the human dose-response at typical residential exposure is less precisely characterized. Speculation re: human low-dose dose-response; established at higher chronic exposures
- Microbiome disruption effects on metabolic and immune outcomes — triclosan's broad-spectrum activity affects oral and gut bacterial communities; the downstream metabolic and immune consequences are an active area. Speculation
- Whether the post-2016 ban achieved its public-health goal of reducing antimicrobial resistance pressure — population-scale resistance trends across the relevant clinical pathogens have not been definitively attributed to or distinguished from the consumer-triclosan reduction. Speculation re: causal attribution
- Replacement antimicrobial chemistry safety profiles — benzalkonium chloride, chloroxylenol, and other triclosan substitutes have their own evidence bases that received less consumer scrutiny than triclosan did before the ban. Inferred from the regrettable-substitution pattern documented for bisphenols and PFAS; triclosan-replacement-specific data is sparse
Citations
- US Food and Drug Administration (2016). Safety and Effectiveness of Consumer Antiseptics; Topical Antimicrobial Drug Products for Over-the-Counter Human Use — Final Rule. Federal Register, 81(172):61106-61130. 21 CFR § 310.545. federalregister.gov Regulatory — 2016 triclosan and triclocarban ban for OTC consumer antiseptic washes
- US Food and Drug Administration. Consumer Antiseptic Wash Final Rule Questions and Answers — implementation guidance. fda.gov Regulatory
- Agency for Toxic Substances and Disease Registry. Public Health Statement for Triclosan. atsdr.cdc.gov Regulatory
- Dann AB, Hontela A (2011). Triclosan: environmental exposure, toxicity and mechanisms of action. Journal of Applied Toxicology, 31(4):285-311. DOI 10.1002/jat.1660 Peer-reviewed
- Calafat AM, Ye X, Wong LY, Reidy JA, Needham LL (2008). Urinary concentrations of triclosan in the U.S. population: 2003-2004. Environmental Health Perspectives, 116(3):303-307. DOI 10.1289/ehp.10768 Peer-reviewed — foundational NHANES triclosan biomonitoring
- Witorsch RJ (2014). Critical analysis of endocrine disruptive activity of triclosan and its relevance to human exposure through the use of personal care products. Critical Reviews in Toxicology, 44(6):535-555. DOI 10.3109/10408444.2014.910754 Peer-reviewed
- Scientific Committee on Consumer Safety. Opinions on Triclosan as cosmetic ingredient — Annex V Entry 25 permits triclosan at 0.3% in specific product types only. health.ec.europa.eu Regulatory
- US Centers for Disease Control and Prevention. National Report on Human Exposure to Environmental Chemicals — NHANES triclosan biomonitoring (post-2016 decline documented). cdc.gov/exposurereport Regulatory
- US Environmental Protection Agency. Triclosan — pesticide registration status and antimicrobial ingredient page. epa.gov/ingredients-used-pesticide-products/triclosan Regulatory
- Halden RU, Lindeman AE, Aiello AE, Andrews D, Arnold WA, Fair P, Fuoco RE, Geer LA, Johnson PI, Lohmann R, McNeill K, Sacks VP, Schettler T, Weber R, Zoeller RT, Blum A (2017). The Florence Statement on Triclosan and Triclocarban. Environmental Health Perspectives, 125(6):064501. DOI 10.1289/EHP1788 Peer-reviewed — multidisciplinary consensus statement
Frequently asked questions
Is triclosan still legal?
Partially. The FDA's September 2016 Final Rule banned triclosan from over-the-counter consumer antiseptic wash products (hand soaps, body washes, bar soaps, foam soaps, gel soaps). Triclosan remains FDA-approved for use in toothpaste at concentrations up to 0.3% — Colgate Total kept its approval based on submitted clinical evidence for gingivitis prevention. Triclosan also remains EPA-registered for some pesticidal and antimicrobial uses, in some treated textiles, and in healthcare antiseptics (a separate FDA regulatory category from the consumer wash rule). The 2016 ban was product-category-specific, not chemical-wide.
Why was triclosan banned in soap?
The FDA's 2016 rationale was twofold. First, the manufacturers had not submitted sufficient evidence to support the "generally recognized as safe and effective" (GRAS/GRAE) standard required for OTC drug ingredients. Second, the public health concern about widespread antimicrobial resistance development from routine consumer-soap use — the FDA's finding was that regular soap and water work as well as antimicrobial soaps for routine hand hygiene without contributing to resistance pressure. The ban was driven more by the cost-benefit analysis (no demonstrated benefit + real public health risk) than by demonstrated direct toxicity to soap users.
Does Colgate Total still have triclosan?
Colgate-Palmolive reformulated Colgate Total in 2019 to remove triclosan and replace it with stannous fluoride. Earlier Colgate Total formulations did contain triclosan (FDA-approved for the gingivitis-prevention indication), but the current product does not. Other major toothpaste brands had also reformulated to triclosan-free formulations during this period. Some specialty and older-stock formulations may still contain triclosan; check current ingredient labels.
What products still contain triclosan?
Since the 2016 FDA ban and the 2019 Colgate reformulation, residential triclosan exposure has declined substantially but is not zero. Some specialty cosmetic products (declining), some antimicrobial-treated textiles (socks, athletic wear, mattress covers — declining since EU and consumer pressure), some healthcare antiseptics (separate FDA category), and some kitchen products marketed with antimicrobial claims still use triclosan. CDC NHANES biomonitoring shows declining urinary triclosan in the US population from pre-2016 detection rates around 92% toward current rates in the 75% range, reflecting the gradual phase-out of consumer applications.
Is triclosan dangerous?
The documented health concerns include thyroid hormone disruption (multiple animal studies show T3/T4 reductions; human evidence more limited), endocrine activity (estrogenic and androgenic at different concentrations), and microbiome effects from the broad-spectrum antimicrobial action. Triclosan has not been classified by IARC. The dominant public health concern that drove the 2016 ban was antimicrobial resistance development from widespread consumer use rather than direct toxicity at residential exposure levels. The biological half-life is approximately 21 hours, which is faster clearance than most environmental contaminants — body burden stops accumulating relatively quickly once exposure ends.
Does triclosan contribute to antibiotic resistance?
The mechanistic concern is documented. Triclosan inhibits bacterial fatty acid synthesis via the FabI enzyme, and bacterial mutations conferring FabI resistance can confer cross-resistance to certain clinically important antibiotics including isoniazid (a tuberculosis drug). The public-health weight given to this concern in the FDA's 2016 decision was substantial. The clinical relevance — whether widespread triclosan consumer use has contributed measurably to antibiotic resistance in clinical pathogens — remains less precisely characterized, but the mechanistic plausibility was sufficient for the regulatory response.
How long does triclosan stay in the body?
The biological half-life is approximately 21 hours — faster than most environmental contaminants and substantially faster than the heavy metals or persistent organic pollutants. Absorbed triclosan is glucuronidated and sulfated in the liver and excreted in urine. Stopping exposure produces rapid reduction in body triclosan; the population-scale biomonitoring data from CDC NHANES has shown the post-2016 decline in urinary triclosan as consumer products were reformulated, consistent with the short half-life and exposure-dependent body burden.
Related compounds
Embr Sleep is a sleep environment company researching the chemistry of the bedroom. See the methodology page for how this Atlas tags claims by evidence strength. For broader context on personal care chemistry and treated-textile exposure, see non-toxic bedroom.
Last reviewed 2026-05-25. If you find a factual error, contact us.