From Wikipedia, the free encyclopedia
Preferred IUPAC name
[(1,3-benzothiazol-2-yl)sulfanyl]methyl thiocyanate
Other names
  • 2-(Thiocyanomethylthio)benzothiazole
  • Thiocyanic acid 2-(benzothiazolethio) methyl ester
  • Casacide[1]
3D model (JSmol)
ECHA InfoCard 100.040.390 Edit this at Wikidata
EC Number
  • 244-445-0
RTECS number
  • XK8150900
  • InChI=1S/C9H6N2S3/c10-5-12-6-13-9-11-7-3-1-2-4-8(7)14-9/h1-4H,6H2
  • C1=CC=C2C(=C1)N=C(S2)SCSC#N
Molar mass 238.34 g·mol−1
Appearance Red to brown liquid with pungent odor [2]
Density 1.05
Melting point −10 °C (14 °F; 263 K)[2]
Boiling point 191 °C (376 °F; 464 K)
Very slightly soluble (0.125 g/L at 24 ° C)[2]
log P 3.23
Vapor pressure 9.0×10−6 mmHg
GHS labelling:
GHS06: ToxicGHS08: Health hazardGHS09: Environmental hazardGHS07: Exclamation mark
H302, H312, H315, H317, H319, H330, H410
P260, P261, P264, P270, P271, P272, P273, P280, P284, P301+P312, P302+P352, P304+P340, P305+P351+P338, P310, P312, P320, P321, P322, P330, P332+P313, P333+P313, P337+P313, P362, P363, P391, P403+P233, P405, P501
Lethal dose or concentration (LD, LC):
679 mg/kg (rat, oral)[2]
200 mg/kg (rabbit, dermal)[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

(Benzothiazol-2-ylthio)methyl thiocyanate (TCMTB) is a chemical compound classified as a benzothiazole.


TCMTB is an oily, flammable, red to brown liquid with a pungent odor that is very slightly soluble in water. It decomposes on heating producing hydrogen cyanide, sulfur oxides, and nitrogen oxides.[2] The degradation products are 2-mercaptobenzothiazole (2-MBT) and 2-benzothiazolesulfonic acid.[3]


TCMTB is used as wideband microbicide, paint fungicide, and paint gallicide.[2] The active substance approved in 1980 in the United States.[3] It is used, for example, in leather preservation,[4] for the protection of paper products, in wood preservatives, and against germs in industrial water.[3]

In the US, TCMTB is used as a fungicide for seed dressing in cereals, safflower, cotton and sugar beet.

It is also used when dealing with fungal problems when extracting hydrocarbons via fracking.[5]


TCMTB is not an authorized plant protection product in the European Union.[6] In Germany, Austria and Switzerland, no plant protection products containing this active substance are authorized.[7]

TCMTB contributes to health problems in tannery workers as it is a potential carcinogen, and is a hepatotoxin. It is also a skin sensitizer, and may cause contact dermatitis in those exposed to the poisonous compound. [8] Hence, it is mainly used in developing countries.


  1. ^ Thomas Swan: Coating Additives & Leather Fungicides
  2. ^ a b c d e f g Record of CAS RN 21564-17-0 in the GESTIS Substance Database of the Institute for Occupational Safety and Health, accessed on 3. August 2012.
  3. ^ a b c EPA: Reregistration Eligibility Decision for 2- (thiocyanomethylthio) benzothiazoles (TCMTB) (PDF; 2.7 MB), August 2006.
  4. ^ Engin Bagda (2000). Biocides in Building Coatings. expert publisher. p. 59. ISBN 3-81691861-1.
  5. ^ Levant, Ezra (2014). Groundswell: The Case for Fracking. McClelland & Stewart. p. 192.
  6. ^ Commission Regulation (EC) No 2076/2002 of 20 November 2002. EUR-Lex Act 319, pp. 3–11 (PDF) "On the extension of the deadline laid down in Article 8 (2) of Council Directive 91/414 / EEC and on the non-inclusion of certain active substances in Annex I to this Directive and the withdrawal of the Authorizations for plant protection products containing these active substances"
  7. ^ PSM-del, EU- 2- (dithiocyanomethylthio) -benzothiazole | CH = DB | A = DB | D = DB | 8 March 2016
  8. ^ "TCMTB - Hazardous Agents | Haz-Map".