Uses and Effectiveness of Triclosan
- Triclosan is used in consumer products such as toothpaste, soaps, detergents, toys, and surgical cleaning treatments.
- It is also found in kitchen utensils, bedding, socks, and trash bags.
- Triclosan is incorporated in conveyor belts, fire hoses, dye bath vats, and ice-making equipment as an antimicrobial.
- It is used in commercial HVAC coils to prevent microbial growth.
- Triclosan is used in surgical scrubs, hand washes, and coatings for surgical sutures.
- Triclosan coated sutures reduce the risk of surgical site infection.
- Antimicrobial hand soaps containing triclosan provide a slightly greater bacterial reduction compared to plain soap.
- Triclosan/copolymer-containing toothpastes reduce dental plaque and gingival inflammation.
- There is weak evidence of a reduction in tooth cavities.
- Triclosan toothpastes do not cause an increase in serious adverse cardiac events.
Chemical Structure and Properties of Triclosan
- Triclosan is a white powdered solid with a slight aromatic, phenolic odor.
- It is soluble in ethanol, methanol, diethyl ether, and strongly basic solutions.
- Triclosan is a chlorinated aromatic compound with functional groups representative of both ethers and phenols.
- It is slightly soluble in water.
- Triclosan can be synthesized from 2,4-dichlorophenol.
Mechanism of Action and Endocrine Disruption of Triclosan
- Triclosan acts as a biocide with multiple cytoplasmic and membrane targets at high concentrations.
- At lower concentrations, it appears bacteriostatic and inhibits fatty acid synthesis.
- Triclosan binds to bacterial enoyl-acyl carrier protein reductase (ENR) enzyme.
- This binding increases the enzyme's affinity for NAD and prevents fatty acid synthesis.
- Vertebrates are not affected by this mode of action.
- Triclosan is a weak endocrine disruptor.
- It binds with low affinity to both the androgen receptor and the estrogen receptor.
- Agonistic and antagonistic responses have been observed.
- The relevance of this to humans is uncertain.
Distribution, Metabolism, and Elimination of Triclosan
- Triclosan is metabolized by humans primarily through conjugation reactions into glucuronide and sulfate conjugates.
- These conjugates are excreted in feces and urine.
- Pharmacokinetic studies show that triclosan sulfate and glucuronide are formed in the liver at approximately equal rates.
- At concentrations below 1 microMolar, sulfonation is the major metabolic pathway for elimination.
- Triclosan concentrations of 1 to 5 microMolar are considered environmentally relevant.
Health Concerns and Environmental Impact of Triclosan
- Triclosan has been designated as a contaminant of emerging concern (CEC) by the United States Geological Survey.
- Potential health concerns include antimicrobial resistance and endocrine disruption.
- Triclosan is thought to accumulate in wastewater and return to drinking water, causing increasing effects with ongoing use.
- The FDA ruled that triclosan is not generally recognized as safe and effective.
- Triclosan is under investigation for public health risk.
- Triclosan has been associated with a higher risk of food allergy.
- Exposure to bacteria may reduce allergies, leading to the association with triclosan.
- Triclosan has been linked to allergic contact dermatitis in some individuals.
- Triclosan concentrations have been associated with allergic sensitization to inhalant and seasonal allergens.
- Triclosan can react with free chlorine in chlorinated tap water, producing other compounds like 2,4-dichlorophenol.
- Some of these intermediates can convert into dioxins upon exposure to UV radiation.
- Triclosan has been detected in human breast milk, blood, and urine samples.
- Triclosan exposure in rats has been shown to modulate estrogen-dependent responses.
- Triclosan possesses (anti)estrogenic and (anti)androgenic properties depending on species, tissues, and cell types.
- Prenatal triclosan exposure has been associated with increased cord testosterone levels in infants.
- Triclosan is persistent in the environment and can accumulate in water, sediment, and organisms.
- Can be toxic to aquatic life, especially algae and fish.
- May contribute to the development of antibiotic resistance in bacteria.
- Can undergo transformation during wastewater treatment, leading to the formation of potentially harmful byproducts.
- Triclosan has been detected in human urine, blood, and breast milk, raising concerns about human exposure.
- Studies suggest that triclosan may disrupt hormone function and affect reproductive and developmental processes.
- Animal studies have shown potential carcinogenic and endocrine-disrupting effects.
- Some studies suggest a link between triclosan exposure and allergies, asthma, and other respiratory conditions.
- Triclosan has been associated with changes in gut microbiota and immune system function.
- The FDA has banned triclosan in over-the-counter consumer antiseptic washes due to lack of evidence for its effectiveness and concerns about its safety.
- Triclosan-coated sutures have been used to reduce the risk of surgical site infections.
- The CDC has included a recommendation for the use of triclosan-coated sutures in surgical procedures.
- Studies have shown that triclosan-coated sutures can effectively reduce the incidence of surgical site infections.
- Triclosan has been used in healthcare facilities to control and prevent the spread of antibiotic-resistant bacteria like MRSA.
- Guidelines for the use of triclosan in healthcare facilities have been developed to ensure proper and safe use.
Triclosan (sometimes abbreviated as TCS) is an antibacterial and antifungal agent present in some consumer products, including toothpaste, soaps, detergents, toys, and surgical cleaning treatments. It is similar in its uses and mechanism of action to triclocarban. Its efficacy as an antimicrobial agent, the risk of antimicrobial resistance, and its possible role in disrupted hormonal development remains controversial. Additional research seeks to understand its potential effects on organisms and environmental health.
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| Names | |||
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| Preferred IUPAC name
5-Chloro-2-(2,4-dichlorophenoxy)phenol | |||
| Other names
2,4,4′-Trichloro-2′-hydroxydiphenyl ether
5-Chloro-(2,4-dichlorophenoxy)phenol Trichloro-2′-hydroxydiphenyl ether CH-3565 Lexol 300 Irgasan DP 300 Ster-Zac | |||
| Identifiers | |||
3D model (JSmol)
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| ChEBI | |||
| ChEMBL | |||
| ChemSpider | |||
| DrugBank | |||
| ECHA InfoCard | 100.020.167 | ||
| KEGG | |||
PubChem CID
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| UNII | |||
CompTox Dashboard (EPA)
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| Properties | |||
| C12H7Cl3O2 | |||
| Molar mass | 289.54 g·mol−1 | ||
| Appearance | White solid | ||
| Density | 1.49 g/cm3 | ||
| Melting point | 55–57 °C (131–135 °F; 328–330 K) | ||
| Boiling point | 120 °C (248 °F; 393 K) | ||
| Pharmacology | |||
| D08AE04 (WHO) D09AA06 (WHO) (medicated dressing) | |||
| Hazards | |||
| NFPA 704 (fire diamond) | |||
| Flash point | 162.2 °C (324.0 °F; 435.3 K) | ||
| Safety data sheet (SDS) | MSDS | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Triclosan was developed in 1966. A 2006 study recommended showering with 2% triclosan as a regimen in surgical units to rid patients' skin of methicillin-resistant Staphylococcus aureus (MRSA). While finding benefit for consumers and no proven risk to human health, but assumed risk of antibiotic resistance, in December 2017, the FDA announced that "consumer antiseptic washes" containing triclosan or 23 other ingredients marketed as antimicrobials were prohibited without pre-market approval. The FDA did find that triclosan in Colgate Total toothpaste helped prevent gingivitis.
triclosan (uncountable)
