2-mercaptobenzothiazole

Structural formula
General
Surname	2-mercaptobenzothiazole
other names	2-mercaptobenzothiazole; 2-mercaptobenzothiazole; Benzothiazole-2-thiol; 2-benzothiazol thiol; MBT; 2-sulfanylbenzothiazole; Captax;
Molecular formula	C 7 H 5 NS 2
Brief description	colorless to yellowish monoclinic needles or leaflets with an unpleasant odor
External identifiers / databases
EC number	205-736-8
ECHA InfoCard	100.005.216
PubChem	697993
ChemSpider	608157
Wikidata	Q904160
properties
Molar mass	167.24 g mol −1
Physical state	firmly
density	1.42 g cm −3 (20 ° C)
Melting point	181 ° C
pK s value	6.93
solubility	very heavy in water (117 mg l −1 at 20 ° C); in acetone : 100 g l −1 ; in ether : 10 g l −1 ; in ethanol : 20 g l −1 ; in benzene : 10 g l −1 ; in carbon tetrachloride : <2 g · l −1 ; in naphtha : <5 g l −1 ;
safety instructions
H and P phrases	H: 317-410
	P: 280-273-302 + 352
MAK	4 mg m −3
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Mercaptobenzothiazole is an organic compound from the group of heteroaromatics . It can sensitize on skin contact and trigger a contact allergy . The thiol group is decisive for the allergenic effect .

Manufacturing

The industrial synthesis of mercaptobenzothiazole uses aniline , sulfur and carbon disulfide as starting materials. These reagents are heated to 235-240 ° C in an autoclave at pressures between 850 and 1100 psi (5.86 to 7.58 MPa).

use

Mercaptobenzothiazole has been used as a vulcanization accelerator (semi-ultraviolet accelerator) and anti- aging agent in rubber production since 1920 . It can be found among others:

in shoe soles
in tires
in cables
in rubber bands
in rubber gloves
in condoms
in hard rubber
in anti-fungal agents ( fungicide )
in veterinary preparations
in technical cutting oils
as a stabilizer in the photo industry
as a reagent for the determination of metals in quantitative analysis
as an aid in the electrochemical coating of metal surfaces

It was developed at Goodyear in 1916 by Clayton Wing Bedford (1885-1933) (Captax).

safety instructions

The occupational exposure limit (OEL) is 4 mg m ⁻³ measured in the inhalable fraction, the odor threshold is 12 mg m ⁻³ .

2-mercaptobenzothiazole was included in the EU's ongoing action plan ( CoRAP ) in 2013 in accordance with Regulation (EC) No. 1907/2006 (REACH) as part of substance evaluation . The effects of the substance on human health and the environment are re-evaluated and, if necessary, follow-up measures are initiated. The reasons for the uptake of 2-mercaptobenzothiazole were concerns about its classification as a CMR substance, consumer use , exposure of sensitive population groups , high (aggregated) tonnage and widespread use as well as the suspected hazards from sensitizing properties. The reassessment took place from 2013 and was carried out by Germany . A final report was then published: Due to the possible allergenic effects, it is recommended to minimize the use of benzothiazole-2-thiol in the vulcanization of rubber in consumer goods as much as possible in order to ensure safe handling.

The International Agency for Research on Cancer (IARC) assessed 2-mercaptobenzothiazole as possibly carcinogenic in early 2016.

Individual evidence

↑ Entry on 1,3-benzothiazol-2-thiol. In: Römpp Online . Georg Thieme Verlag, accessed on March 31, 2014.
↑ ^a ^b ^c ^d ^e Entry on benzothiazole-2-thiol in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .
↑ ^a ^b Entry on 2-mercaptobenzotriazole in the SRC PhysProp Database , accessed on September 11, 2012.
↑ ^a ^b ^c ^d ^e ^f ^g Toxicological assessment of 2-mercaptobenzothiazole (PDF) from the professional association raw materials and chemical industry (BG RCI), accessed on May 1, 2018.
↑ Entry on Benzothiazole-2-thiol in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ I. Chipinda, XD Zhang, RH Simoyi, PD Siegel: Mercaptobenzothiazoles allergenicity-role of the thiol group. In: Cutan Ocul Toxicol. 27 (2), 2008, pp. 103-116, PMID 18568896 .
↑ Patent US2090233 : Process for manufacture of mercapto aryl thiazoles. Registered November 1, 1935 , published August 17, 1937 , Applicant: Wingfoot , Inventor: Harold P Roberts. ‌
^ European Chemicals Agency (ECHA): Substance Evaluation Report and Conclusion Document .
↑ Community rolling action plan ( CoRAP ) of the European Chemicals Agency (ECHA): Benzothiazole-2-thiol , accessed on March 26, 2019.
↑ Yann Grosse, Dana Loomis, Kathryn Z. Guyton, Fatiha El Ghissassi, Véronique Bouvard, Lamia Benbrahim-Tallaa, Heidi Mattock, Kurt Straif: Carcinogenicity of some industrial chemicals . In: The Lancet Oncology . February 23, 2016, doi : 10.1016 / S1470-2045 (16) 00137-6 (English).

[1] Entry on 1,3-benzothiazol-2-thiol. In: Römpp Online . Georg Thieme Verlag, accessed on March 31, 2014.

[GESTIS-2] Entry on benzothiazole-2-thiol in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .

[SRC-3] Entry on 2-mercaptobenzotriazole in the SRC PhysProp Database , accessed on September 11, 2012.

[BG-Chemie-4] ↑ ^a ^b ^c ^d ^e ^f ^g Toxicological assessment of 2-mercaptobenzothiazole (PDF) from the professional association raw materials and chemical industry (BG RCI), accessed on May 1, 2018.

[CLP_100.005.216-5] Entry on Benzothiazole-2-thiol in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[6] I. Chipinda, XD Zhang, RH Simoyi, PD Siegel: Mercaptobenzothiazoles allergenicity-role of the thiol group. In: Cutan Ocul Toxicol. 27 (2), 2008, pp. 103-116, PMID 18568896 .

[PAT1-7] Patent US2090233 : Process for manufacture of mercapto aryl thiazoles. Registered November 1, 1935 , published August 17, 1937 , Applicant: Wingfoot , Inventor: Harold P Roberts. ‌

[8] European Chemicals Agency (ECHA): Substance Evaluation Report and Conclusion Document .

[9] Community rolling action plan ( CoRAP ) of the European Chemicals Agency (ECHA): Benzothiazole-2-thiol , accessed on March 26, 2019.

[10] Yann Grosse, Dana Loomis, Kathryn Z. Guyton, Fatiha El Ghissassi, Véronique Bouvard, Lamia Benbrahim-Tallaa, Heidi Mattock, Kurt Straif: Carcinogenicity of some industrial chemicals . In: The Lancet Oncology . February 23, 2016, doi : 10.1016 / S1470-2045 (16) 00137-6 (English).