| Reference | [1]. Contact Dermatitis. 2019 Oct;81(4):262-265. doi: 10.1111/cod.13295. Epub 2019 May 31.<br />
The preservative 2-(thiocyanomethylthio)benzothiazole: A potential allergen in leather products.<br />
Herman A(1), Goossens A(2), Tennstedt D(1), Bergendorff O(3), Isaksson M(3), Mowitz M(3), Baeck M(1).<br />
Author information: (1)Department of Dermatology, Cliniques Universitaires Saint-Luc, Brussels, Belgium. (2)Department of Dermatology, University Hospitals KU Leuven, Leuven, Belgium. (3)Department of Occupational and Environmental Dermatology, Lund University, Skane University Hospital, Malmö, Sweden.<br />
BACKGROUND: Allergic contact dermatitis caused by leather is common, and several responsible allergens, such as tanning agents, glues, mercaptobenzothiazole derivatives, and dyes, but also antimicrobials and antifungals, are involved. MATERIAL AND METHODS: Three female patients were referred to the Departments of Dermatology in a Belgian university hospital following skin reactions caused by leather products (shoes, belt, and car seats). They were patch tested with the European baseline series and samples of suspected leather products, and additionally with 2-(thiocyanomethylthio)benzothiazole (TCMTB), an antifungal agent previously reported to be a contact allergen in footwear. Chromatographic analyses of samples of all the leather materials tested were performed at the Department of Occupational and Environmental Dermatology in Malmö, Sweden. RESULTS: The patients reacting to the leather samples were shown to be sensitized to TCMTB, the presence of which could be confirmed by chemical analyses of samples obtained from the patients. CONCLUSION: Patch tests with TCMTB should be considered in patients with contact dermatitis caused by leather items.<br />
DOI: 10.1111/cod.13295 PMID: 31006870 [Indexed for MEDLINE]<br />
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[2]. Arch Environ Contam Toxicol. 2005 Apr;48(3):344-50. doi: 10.1007/s00244-004-0105-1. Epub 2005 Feb 15.<br />
Comparative aquatic toxicity evaluation of 2-(thiocyanomethylthio)benzothiazole and selected degradation products using Ceriodaphnia dubia.<br />
Nawrocki ST(1), Drake KD, Watson CF, Foster GD, Maier KJ.<br />
Author information: (1)Department of Cancer Biology, University of Texas-Houston, M.D. Anderson Cancer Center, Houston, Texas 77001, USA.<br />
2-(Thiocyanomethylthio)benzothiazole (TCMTB) is a biocide used in the leather, pulp and paper, and water-treatment industries. TCMTB may enter aquatic ecosystems during its manufacture and use. TCMTB is environmentally unstable; therefore, it is important to evaluate the toxicity of the more persistent degradation products. This study compared the toxicity of TCMTB with its degradation products 2-mercaptobenzothiazole (2-MBT), 2-(methylthio)benzothiazole (MTBT), benzothiazole (BT), and 2-hydroxybenzothiazole (HOBT). Toxicity was determined using Ceriodaphnia dubia 48-hour acute and 7-day chronic test protocols. TCMTB was the most toxic compound evaluated in both the acute and chronic tests with EC50s of 15.3 and 9.64 microg/L, respectively. 2-MBT, the first degradation product, was the second most toxic compound with acute and chronic EC50s of 4.19 and 1.25 mg/L, respectively. The toxicity of MTBT and HOBT were similar with acute EC50s of 12.7 and 15.1 mg/L and chronic EC50s of 6.36 and 8.31 mg/L, respectively. The least toxic compound was BT with acute and chronic EC50s of 24.6 and 54.9 mg/L, respectively. TCMTB was orders of magnitude more toxic than its degradation products. Toxicity data on these benzothiazole degradation products is important because of concerns regarding their release, degradation, persistence, and non-target organism effects in aquatic ecosystems.<br />
DOI: 10.1007/s00244-004-0105-1 PMID: 15750776 [Indexed for MEDLINE]<br />
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[3]. Arch Toxicol. 1996;70(9):579-84. doi: 10.1007/s002040050315.<br />
Determination of urinary 2-mercaptobenzothiazole (2-MBT), the main metabolite of 2-(thiocyanomethylthio)benzothiazole (TCMTB) in humans and rats.<br />
Manninen A(1), Auriola S, Vartiainen M, Liesivuori J, Turunen T, Pasanen M.<br />
Author information: (1)Finnish Institute of Occupational Health, Kuopio, Finland.<br />
A method for biological monitoring of urinary 2-(thiocyanomethylthio)benzothiazole (TCMTB), a wood preservative and an industrial chemical, was developed. Three different doses of TCMTB in olive oil were given to male rats by gavage for 3 weeks. Urine was collected daily and the metabolites were analysed as thioethers by derivatization with pentafluorobenzyl-bromide by gas chromatography-mass spectrometry. The parent chemical was not detected in urine samples, but two metabolites of TCMTB were identified. 2-Mercaptobenzothiazole (2-MBT) was the main metabolite, and its excretion varied according to the dose. The second metabolite was 2-(mercaptomethylthio)benzothiazole. The amount of 2-MBT excreted in rat urine was 66 +/- 12% (SD), 51 +/- 20% and 44 +/- 9% for TCMTB doses of 15, 75 and 150 mg/kg, respectively. Two doses, 75 and 150 mg/kg, caused diuresis in rats during the 1 week of dosing. During the 3-week TCMTB treatment, rat liver microsomal CYP enzyme profile was not significantly changed. Urine samples of sawmill workers exposed to TCMTB were collected after their work shifts for exposure assessment. TCMTB could not be detected in the urine samples of exposed workers. Most concentrations of 2-MBT were below the limit of the detection, 0.12 mumol/l, the concentrations were 0.12-0.15 mumol/l only in few cases. The determination of 2-MBT in urine, when a sample is taken immediately after a work shift, is a suitable indicator of workers' exposure to TCMTB.<br />
DOI: 10.1007/s002040050315 PMID: 8831908 [Indexed for MEDLINE]<br />
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[4]. Bull Environ Contam Toxicol. 2020 Sep;105(3):433-439. doi: 10.1007/s00128-020-02954-2. Epub 2020 Aug 1.<br />
Photodegradation of Emerging Contaminant 2-(tiocyanomethylthio) Benzothiazole (TCMTB) in Aqueous Solution: Kinetics and Transformation Products.<br />
Bertoldi C(1)(2), de Cássia Campos Pena A(3), Dallegrave A(4), Fernandes AN(5), Gutterres M(3).<br />
Author information: (1)Laboratory of Leather and Environmental Studies (LACOURO), Chemical Engineering Department, Federal University of Rio Grande do Sul (UFRGS), Av. Luiz Englert s/n°, 90040- 040, Porto Alegre, Brazil. [email protected]. (2)Instituto de Química, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, n° 9500, 91501-970, Porto Alegre, Brazil. [email protected]. (3)Laboratory of Leather and Environmental Studies (LACOURO), Chemical Engineering Department, Federal University of Rio Grande do Sul (UFRGS), Av. Luiz Englert s/n°, 90040- 040, Porto Alegre, Brazil. (4)Instituto de Química, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, n° 9500, 91501-970, Porto Alegre, Brazil. (5)Instituto de Química, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, n° 9500, 91501-970, Porto Alegre, Brazil. [email protected].<br />
Direct photolysis of the emerging contaminant 2-(thiocyanomethylthio) benzothiazole (TMCTB) was performed in aqueous solution at different concentrations with high-pressure mercury lamp (5.0, 8.0, 13.0, 16.0, 20.0, 23.0, 27.0, 35.0, 40.0, 45.0, and 50.0 mg L- 1) and with natural sunlight radiation (6.0, 30.0, and 60.0 mg L- 1). TCMTB underwent rapid degradation by direct photolysis with a high-pressure mercury lamp in aqueous solutions, with 99% removal after 30 min at all concentrations studied. For sunlight photolysis, TCMTB degradation was observed with 96%, 81%, and 64% removal for initial concentrations of 6.0, 30.0, and 60.0 mg L- 1, respectively, after 7 h of exposure to sunlight. The degradation of TCMTB in lab-scale wastewater had kinetic constant and t1/2 in the same order when compared to the photodegradation of TCMTB in aqueous solutions. In addition, the results showed that photolysis with a high-pressure mercury lamp and sunlight were governed by the same kinetic order, however the kinetic parameters showed that degradation with sunlight was 40 times slower than photolysis with the mercury lamp. Twelve transformation products (TP) were identified, and eight of the TP have not been described in the literature. Furthermore, prediction of toxicity with ECOSAR software was carried out for fish, daphnids, and green algae species. It showed that photolytic treatment is efficient for reducing the toxicity of the compound, since the degradation formed compounds with lower toxicity than the primary compound. In conclusion, this study suggests that photolysis is an efficient way to remove the studied contaminant, and it highlights the potential of this technique for the degradation of emerging contaminants in industrial wastewater treatment plants.<br />
DOI: 10.1007/s00128-020-02954-2 PMID: 32740745 [Indexed for MEDLINE]<br />
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[5]. Environ Sci Technol. 2018 May 1;52(9):5007-5026. doi: 10.1021/acs.est.7b05493. Epub 2018 Apr 10.<br />
A Review of Environmental Occurrence, Fate, Exposure, and Toxicity of Benzothiazoles.<br />
Liao C(1), Kim UJ(2), Kannan K(2).<br />
Author information: (1)State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China. (2)Wadsworth Center, New York State Department of Health, and Department of Environmental Health Sciences, School of Public Health , State University of New York at Albany , Empire State Plaza , P.O. Box 509, Albany , New York 12201-0509 , United States.<br />
Benzothiazole and its derivatives (BTs) are high production volume chemicals that have been used for several decades in a large number of industrial and consumer products, including vulcanization accelerators, corrosion inhibitors, fungicides, herbicides, algicides, and ultraviolet (UV) light stabilizers. Several benzothiazole derivatives are used commercially, and widespread use of these chemicals has led to ubiquitous occurrence in diverse environmental compartments. BTs have been reported to be dermal sensitizers, respiratory tract irritants, endocrine disruptors, carcinogens, and genotoxicants. This article reviews occurrence and fate of a select group of BTs in the environment, as well as human exposure and toxicity. BTs have frequently been found in various environmental matrices at concentrations ranging from sub-ng/L (surface water) to several tens of μg/g (indoor dust). The use of BTs in a number of consumer products, especially in rubber products, has resulted in widespread human exposure. BTs undergo chemical, biological, and photolytic degradation in the environment, creating several transformation products. Of these, 2-thiocyanomethylthio-benzothiazole (2-SCNMeS-BTH) has been shown to be the most toxic. Epidemiological studies have shown excess risks of cancers, including bladder cancer, lung cancer, and leukemia, among rubber factory workers, particularly those exposed to 2-mercapto-benzothiazole (2-SH-BTH). Human exposure to BTs continues to be a concern.<br />
DOI: 10.1021/acs.est.7b05493 PMID: 29578695 [Indexed for MEDLINE]
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