Names | |
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Preferred IUPAC name N-(4-Chlorophenyl)-N′-(3,4-dichlorophenyl)urea | |
Other names Trichlorocarbanilide, TCC, Solubacter, Vivilide | |
Identifiers | |
3D model (JSmol) | |
ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.002.659 |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C13H9Cl3N2O | |
Molar mass | 315.58 g·mol−1 |
Density | 1.53 g/cm3 |
Melting point | 254 to 256 °C (489 to 493 °F; 527 to 529 K) |
Hazards | |
NFPA 704 (fire diamond) | |
Flash point | >150 °C (302 °F; 423 K) |
Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | >5000 mg/kg (oral, mouse) [1] 2100 mg/kg (i.p., mouse) [1] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Triclocarban (sometimes abbreviated as TCC) is an antibacterial chemical once common in, but now phased out of, personal care products like soaps and lotions. It was originally developed for the medical field. [2] Although the mode of action is unknown, TCC can be effective in fighting infections by targeting the growth of bacteria such as Staphylococcus aureus . [3] Additional research seeks to understand its potential for causing antibacterial resistance and its effects on organismal and environmental health. [4]
Triclocarban has been used as an antimicrobial and antifungal compound since the 1960s. [5] It was commonly found in personal care products as an antimicrobial in soaps, lotions, deodorants, toothpaste, and plastic. [6] As of 2005 [update] about 80% of all antimicrobial bar soap sold in the United States contained triclocarban. [5] In 2011 United States consumers were spending nearly 1 billion dollars annually on products containing triclocarban and triclosan. [7]
In December 2013, the Food and Drug Administration (FDA) required all companies to prove within the next year, that triclocarban is not harmful to consumers. Companies like Johnson & Johnson, Procter & Gamble, Colgate-Palmolive, and Avon began phasing out antibacterial ingredients due to health concerns. [8]
By 2016 usage of triclocarban in soaps had declined to 40%, and that September the FDA banned triclocarban, triclosan and 17 other common antibacterial chemicals by September 2017, for their failure to be proven safe, or more effective than plain soap and water. [9]
Triclocarban, 3-(4-chlorophenyl)-1-(3,4-dichlorophenyl)urea, is a white powder that is insoluble in water. While triclocarban has two chlorinated phenyl rings, it is structurally similar to carbanilide compounds often found in pesticides (such as diuron) and some drugs. Chlorination of ring structures is often associated with hydrophobicity, persistence in the environment, and bioaccumulation in fatty tissues of living organisms. For this reason, chlorine is also a common component of persistent organic pollutants. [10] Triclocarban is incompatible with strong oxidizing reagents and strong bases, reaction with which could result in safety concerns such as explosion, toxicity, gas, and heat.
There are two commercial routes used for the production of triclocarban, using the reaction of isocyanates with nucleophiles such as amines to form ureas: [11]
The purity specification in the draft USP monograph for triclocarban is: not less than 97.0% w/w. The purity of commercial production is greater, 98% w/w. [12]
Triclocarban is predominantly active against gram positive bacteria (bacteria with a thick peptidoglycan wall). The precise mechanism of action of triclocarban is unknown, but it is shown to be bacteriostatic, which prevents bacterial proliferation. [13]
The specific mechanism of action for triclocarban's health effects on humans, like in bacteria, is unclear. Generally, in vitro, triclocarban enhances the gene expression of other steroid hormones, including androgens, estrogens, and cortisol. It is hypothesized that the compound acts similar to cofactors or coactivators that modulate the activity of estrogen receptors and androgen receptors. [14] [15] Experiments show that triclocarban activates constitutive androstane receptor and estrogen receptor alpha both in vivo and in vitro and might have the potential to alter normal physiological homeostasis. Activation of these receptors amplifies gene expression and, in doing so, may be the mechanistic base of triclocarban's health impact on humans. However, further investigation is needed to determine whether triclocarban increases the activity of sex steroid hormones by binding to the receptors or by binding to and sensitizing the receptor coactivators. [16] [17]
Triclocarban acts to treat both initial bacterial skin and mucosal infections as well as those infections at risk for superinfection. In vitro, triclocarban has been found to be effective against various strains of staphylococcus, streptococcus, and enterococcus bacteria. It has been shown to be effective as an antibacterial even at very low levels. Triclocarban's minimum inhibitory concentration has been found to range from 0.5 to 8 mg/L for these various strains. [18] Triclocarban is unquestionably bacteriostatic only for gram-positive bacteria such as Staphylococcus aureus, which suggests that the mechanism of triclocarban's antibacterial activity is through its destabilization of bacterial cell walls. [5]
Exposure of organisms like fish, algae, and humans to low levels of triclocarban and other antibacterial chemicals kills weak microbes and allows the stronger, resistant strains to proliferate. As microbes share genes, an increase in resistant strains increases the probability that weak microbes acquire these resistance genes. The consequence is a new colony of drug resistant microbes. [19]
When resistant microbes are exposed to antimicrobials, they increase their expression of genes that confer this resistance. The risk of bacterial antibiotic resistance has been studied by quantitatively monitoring the abundance of the tetQ gene in wastewater microcosms. As tetQ is the most common resistance gene in the environment and encodes for ribosomal protection proteins, the amount that it expresses correlates with the amount of resistance in a microbial population. The addition of triclocarban was shown to increase the expression of this tetQ gene. [19]
TetQ gene expression in bacteria was also found to be significantly increased when multiple antimicrobials such as tetracycline, triclosan, and triclocarban were added to an experimental system at the same time. Combining these compounds affects resistance by creating a situation where co-selection (or natural selection by more than one reagent) for resistance genes occurs. The complex nature of microbial communities and the multitude of antibiotics present in aquatic environments often leads to this sort of dynamic selection event and the multiple resistance patterns seen in naturally occurring bacteria. [19]
When triclocarban is manufactured, 139 toxic, carcinogenic byproducts, such as 4-chloroaniline and 3,4-dichloroaniline, are released. More of these carcinogens can be released upon chemical, physical and biological attack of triclocarban. [20] The duration of triclocarban chemical in personal product use is relatively short. Upon disposal, the triclocarban is washed down the drain to municipal wastewater treatment plants, where about 97-98% of triclocarban is removed from the water.
Discharge of effluent from these treatment plants and disposal of sludge on land is the primary route of environmental exposure to triclocarban. Research shows that triclocarban and triclosan have been detected in sewage effluents and sludge (biosolids) due to their incomplete removal during wastewater treatment. [21] Due to their hydrophobic nature, significant amounts of them in wastewater streams partition into sludge, with concentrations at mg/kg levels. The volume of triclocarban reentering the environment in sewage sludge after initial successful capture from wastewater is s 127,000 ± 194,000 kg/yr. This is equivalent to a 4.8 – 48.2% of its total U.S. consumption volume. Crops shown to take up antimicrobials from soil include barley, meadow fescue, carrots and pinto beans. [20] Studies show that substantial quantities of triclocarban (227,000 – 454,000 kg/y) can break through wastewater treatment plants and damage algae on surface waters. [20]
High concentrations of triclocarban may be found in wastewater. As of 2011 it was among the top ten most commonly detected organic wastewater compounds in terms of frequency and concentration. Triclocarban has been found in increasing concentrations over the past five years and is now more frequently detected than triclosan. [6]
Triclocarban has a hazard quotient rating of greater than one, which indicates the potential for adverse effects on organisms due to toxicity. [6] As triclocarban is found in high concentrations in aquatic environments, there are concerns regarding its toxicity to aquatic species. Specifically, triclocarban has been shown to be toxic to amphibians, fish, invertebrates, and aquatic plants, and traces of the compound have been found in Atlantic dolphins. [6] [22] Triclocarban may disrupt hormones critical to the developmental and endocrine processes in exposed animal wildlife. The neurological and reproductive systems are particularly affected through contact with this compound. Triclocarban may also affect animal wildlife behavior. [22] For example, triclosan and triclocarban are 100–1,000 times more effective in inhibiting and killing algae, crustaceans, and fish than they are in killing microbes. Triclocarban and triclosan have been observed in multiple organisms, including algae, aquatic blackworms, fish, and dolphins. [20]
Triclocarban bioaccumulation is possible in a number of organisms. Earthworms are known to store this chemical in their bodies and, because of their ecological role as a food source, they have the potential to move triclocarban up the food chain. [23] Microbial species found in soils also bioaccumulate triclocarban. However, the health of these microbes has not been found to be affected by the presence of the chemical. [24] Triclocarban is rapidly accumulated in both algae and adult caged snails. [25] Moreover, triclocarban is more likely than triclosan to bioaccumulate in aquatic organisms. [26]
Bioaccumulation occurs in plants treated with water containing triclocarban. However, it is estimated that less than 0.5% of the acceptable daily intake of triclocarban for humans is represented by vegetable consumption. Thus, the concentration of triclocarban in edible portions of plants is a negligible exposure pathway for humans.[ citation needed ]
The potential for triclocarban to bioaccumulate in plants has been exploited in the construction of wetlands meant to help remove triclocarban from wastewater. These constructed wetlands are considered a cost-effective treatment option for the removal of PPCPs, including triclocarban and triclosan, from domestic water effluent. Such compounds tend to concentrate in the roots of wetland plants. Potential ecological risks associated with this method are the decrease of root systems in wetland plants, reduced nutrient uptake, decreased competitive ability, and increased potential for uprooting. Due to these risks, the long term exposure of wetland ecosystems to wastewater containing triclocarban as a major solution to wastewater pollution is still under discussion. [27]
One study has investigated how triclocarban remains in the human system after using a bar of soap with traces of triclocarban. Analysis of urine samples from human test subjects shows that, after triclocarban has undergone glucuronidation, its oxidative metabolites are less readily excreted than triclocarban itself. This same study performed topical treatments of triclocarban on rats and, by analyzing urine and plasma levels, demonstrated that triclocarban does remain in the organism's system. [28]
Triclocarban induces weak responses mediated by aryl hydrocarbon, estrogen, and androgen receptors in vitro. This has yet to be confirmed in vivo. [29] In vitro, the dihydrotestosterone-dependent activation of androgen receptor-responsive gene expression is enhanced by triclocarban by up to 130%. [30] Triclocarban is also a potent inhibitor of the enzyme soluble epoxide hydrolase (sEH) in vitro. [28] Additionally, triclocarban amplifies the bioactivity of testosterone and other androgens. This increased activity may have adverse implications for reproductive health. [7] [23] Triclocarban studies on rats exhibited increased size of the specimens' prostate glands. [31] The amplification of sex hormones could promote the growth of breast and prostate cancer.[ citation needed ]
The chemical toxicity of triclocarban with respect to lethality is low (LD50 >5000 mg/kg). Its rate of skin absorption is also low. [32] Repeated low-dose exposure, however, can cause endocrine disruption over time.[ citation needed ]
Spillage may increase the risk of human, ecological, and environmental exposure to triclocarban. Immediate removal and restraint of the spill, including triclocarban as dust, is urged. [31] Although triclocarban has few to no direct detrimental effects on health aside from allergic reactions, preventing exposure to triclocarban is recommended. Since triclocarban enters the body through pores, wearing gloves, properly washing hands, and overall proper hygiene reduces the risk of skin exposure and irritation. High concentrations of triclocarban dust may remain in the lungs and inhibit lung and respiratory function. For individuals with prior respiratory conditions, triclocarban exacerbates the severity of respiratory diseases, and proper protection is recommended as a precaution. In case of exposure to triclocarban, the individual is suggested to wash the area with water or to clear the respiratory pathways. [31] In addition to its adverse effects on humans and the environment, solid triclocarban is a fire hazard. It is particularly combustible as dust. Contamination with other oxidizing agents may also result in combustion. [31]
The Food and Drug Administration began to review the safety of triclocarban and triclosan in the 1970s, but due to the difficulties of finding antimicrobial alternatives, no final policy, or "drug monograph," was established. [20] Legal action by the Natural Resources Defense Council in 2010 forced the FDA to review triclocarban and triclosan. [20] The United States Environmental Protection Agency maintains regulatory control over triclocarban and triclosan. [20]
On September 2, 2016, the Food and Drug Administration announced that triclosan and triclocarban must be removed from all antibacterial soap products by late 2017. [9] [33] Triclocarban is similar in its use and adverse health impacts as triclosan, and hexachlorophene which was already prohibited by the FDA. [20]
Scientists are searching for more sustainable antimicrobials that maintain their effectiveness while being minimally toxic to the environment, humans, and wildlife. This entails low degrees of bioaccumulation and rapid, clean biodegradation in existing wastewater treatment facilities. A lowered potential or no potential for resistance is also preferable. [20] These next generation chemicals should aim to act on a broad spectrum of microbes and pathogens while also being minimally toxic and bioaccumulating in non-target species.[ citation needed ]
Synthesis of these compounds could be improved upon by finding renewable sources for their production that lacks occupational hazards. [20] Research into sustainable chemical production is helping to formulate green pharmaceuticals. These same principles may be applied to the development of improved antimicrobials. [20] Developments in this area would benefit both people and the environment. [20]
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of such infections. They may either kill or inhibit the growth of bacteria. A limited number of antibiotics also possess antiprotozoal activity. Antibiotics are not effective against viruses such as the ones which cause the common cold or influenza. Drugs which inhibit growth of viruses are termed antiviral drugs or antivirals. Antibiotics are also not effective against fungi. Drugs which inhibit growth of fungi are called antifungal drugs.
Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Bioaccumulation occurs when an organism absorbs a substance faster than it can be lost or eliminated by catabolism and excretion. Thus, the longer the biological half-life of a toxic substance, the greater the risk of chronic poisoning, even if environmental levels of the toxin are not very high. Bioaccumulation, for example in fish, can be predicted by models. Hypothesis for molecular size cutoff criteria for use as bioaccumulation potential indicators are not supported by data. Biotransformation can strongly modify bioaccumulation of chemicals in an organism.
Drug resistance is the reduction in effectiveness of a medication such as an antimicrobial or an antineoplastic in treating a disease or condition. The term is used in the context of resistance that pathogens or cancers have "acquired", that is, resistance has evolved. Antimicrobial resistance and antineoplastic resistance challenge clinical care and drive research. When an organism is resistant to more than one drug, it is said to be multidrug-resistant.
Antibacterial soap is a soap which contains chemical ingredients that purportedly assist in killing bacteria. The majority of antibacterial soaps contain triclosan, though other chemical additives are also common. The effectiveness of products branded as being antibacterial has been disputed by some academics as well as the U.S. Food and Drug Administration (FDA).
Triclosan 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.
A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than sterilization, which is an extreme physical or chemical process that kills all types of life. Disinfectants are generally distinguished from other antimicrobial agents such as antibiotics, which destroy microorganisms within the body, and antiseptics, which destroy microorganisms on living tissue. Disinfectants are also different from biocides—the latter are intended to destroy all forms of life, not just microorganisms. Disinfectants work by destroying the cell wall of microbes or interfering with their metabolism. It is also a form of decontamination, and can be defined as the process whereby physical or chemical methods are used to reduce the amount of pathogenic microorganisms on a surface.
Parabens are chemicals that are commonly used as preservatives in cosmetic and pharmaceutical products. Chemically, they are a series of parahydroxybenzoates or esters of parahydroxybenzoic acid. Research is being conducted to evaluate the potential health implications of paraben usage.
An antimicrobial is an agent that kills microorganisms (microbicide) or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria, and antifungals are used against fungi. They can also be classified according to their function. Antimicrobial medicines to treat infection are known as ⠀⠀antimicrobial chemotherapy, while antimicrobial drugs are used to prevent infection, which known as antimicrobial prophylaxis.
Bisphenol A (BPA) is a chemical compound primarily used in the manufacturing of various plastics. It is a colourless solid which is soluble in most common organic solvents, but has very poor solubility in water. BPA is produced on an industrial scale by the condensation reaction of phenol and acetone. Global production in 2022 was estimated to be in the region of 10 million tonnes.
Microbial ecology is the ecology of microorganisms: their relationship with one another and with their environment. It concerns the three major domains of life—Eukaryota, Archaea, and Bacteria—as well as viruses. This relationship is often mediated by secondary metabolites produced my microorganism. These secondary metabolites are known as specialized metabolites and are mostly volatile or non volatile compounds. These metabolites include terpenoids, sulfur compounds, indole compound and many more.
Nonylphenols are a family of closely related organic compounds composed of phenol bearing a 9 carbon-tail. Nonylphenols can come in numerous structures, all of which may be considered alkylphenols. They are used in manufacturing antioxidants, lubricating oil additives, laundry and dish detergents, emulsifiers, and solubilizers. They are used extensively in epoxy formulation in North America but its use has been phased out in Europe. These compounds are also precursors to the commercially important non-ionic surfactants alkylphenol ethoxylates and nonylphenol ethoxylates, which are used in detergents, paints, pesticides, personal care products, and plastics. Nonylphenol has attracted attention due to its prevalence in the environment and its potential role as an endocrine disruptor and xenoestrogen, due to its ability to act with estrogen-like activity. The estrogenicity and biodegradation heavily depends on the branching of the nonyl sidechain. Nonylphenol has been found to act as an agonist of the GPER (GPR30).
Xenoestrogens are a type of xenohormone that imitates estrogen. They can be either synthetic or natural chemical compounds. Synthetic xenoestrogens include some widely used industrial compounds, such as PCBs, BPA, and phthalates, which have estrogenic effects on a living organism even though they differ chemically from the estrogenic substances produced internally by the endocrine system of any organism. Natural xenoestrogens include phytoestrogens which are plant-derived xenoestrogens. Because the primary route of exposure to these compounds is by consumption of phytoestrogenic plants, they are sometimes called "dietary estrogens". Mycoestrogens, estrogenic substances from fungi, are another type of xenoestrogen that are also considered mycotoxins.
Hand sanitizer is a liquid, gel, or foam used to kill viruses, bacteria, and other microorganisms on the hands. It can also come in the form of a cream, spray, or wipe. While hand washing with soap and water is generally preferred, hand sanitizer is a convenient alternative in settings where soap and water are unavailable. However, it is less effective against certain pathogens like norovirus and Clostridioides difficile and cannot physically remove harmful chemicals. Improper use, such as wiping off sanitizer before it dries, can also reduce its effectiveness, and some sanitizers with low alcohol concentrations are less effective. Additionally, frequent use of hand sanitizer may disrupt the skin's microbiome and cause dermatitis.
In microbiology, the minimum inhibitory concentration (MIC) is the lowest concentration of a chemical, usually a drug, which prevents visible in vitro growth of bacteria or fungi. MIC testing is performed in both diagnostic and drug discovery laboratories.
Cross-resistance is when something develops resistance to several substances that have a similar mechanism of action. For example, if a certain type of bacteria develops resistance to one antibiotic, that bacteria will also have resistance to several other antibiotics that target the same protein or use the same route to get into the bacterium. A real example of cross-resistance occurred for nalidixic acid and ciprofloxacin, which are both quinolone antibiotics. When bacteria developed resistance to ciprofloxacin, they also developed resistance to nalidixic acid because both drugs inhibit topoisomerase, a key enzyme in DNA replication. Due to cross-resistance, antimicrobial treatments like phage therapy can quickly lose their efficacy against bacteria. This makes cross-resistance an important consideration in designing evolutionary therapies.
Triphenyl phosphate (TPhP) is the chemical compound with the formula OP(OC6H5)3. It is the simplest aromatic organophosphate. This colourless solid is the ester (triester) of phosphoric acid and phenol. It is used as a plasticizer and a fire retardant in a wide variety of settings and products.
A soap substitute is a natural or synthetic cleaning product used in place of soap or other detergents, typically to reduce environmental impact or health harms or provide other benefits.
An antimicrobial surface is coated by an antimicrobial agent that inhibits the ability of microorganisms to grow on the surface of a material. Such surfaces are becoming more widely investigated for possible use in various settings including clinics, industry, and even the home. The most common and most important use of antimicrobial coatings has been in the healthcare setting for sterilization of medical devices to prevent hospital-associated infections, which have accounted for almost 100,000 deaths in the United States. In addition to medical devices, linens and clothing can provide a suitable environment for many bacteria, fungi, and viruses to grow when in contact with the human body which allows for the transmission of infectious disease.
Sex is influenced by water pollutants that are encountered in everyday life. These sources of water can range from the simplicity of a water fountain to the entirety of the oceans. The pollutants within the water range from endocrine disruptor chemicals (EDCs) in birth control to Bisphenol A (BPA). Foreign substances such as chemical pollutants that cause an alteration of sex have been found in growing prevalence in the circulating waters of the world. These pollutants have affected not only humans, but also animals in contact with the pollutants.
Drug pollution or pharmaceutical pollution is pollution of the environment with pharmaceutical drugs and their metabolites, which reach the aquatic environment through wastewater. Drug pollution is therefore mainly a form of water pollution.
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