Language selection

Government of Canada / Gouvernement du Canada

Search

Benzotriazoles and Benzothiazoles Group

Information sheet

These substances were identified for action under the Chemicals Management Plan (CMP). The assessment focused on 15 substances referred to collectively under the CMP as the Benzotriazoles and Benzothiazoles Group. The substances in the benzothiazoles subgroup all contain the 2-mercaptobenzothiazole (MBT) moiety; therefore, the conclusion for this subgroup includes MBT and its precursors and is not limited to the 6 benzothiazole substances in the table below.

Summary of publications
Substance group Subgroup CAS RN Common name or acronym DSL name Public comments on the draft screening assessment Final assessment Proposed risk management approach Conclusion on section 64 criteria Follow-up activities
Benzotriazoles and Benzothiazoles Group Benzotriazoles 95-14-7 Benzotriazole 1H-Benzotriazole HTML HTML None Do not meet None planned at this time
3147-75-9 UV-329 Phenol, 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)-
3846-71-7 UV-320 Phenol, 2-(2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylethyl)-
3896-11-5 UV-326 Phenol, 2-(5-chloro-2H-benzotriazol-2-yl)-6-(1,1-dimethylethyl)-4-methyl-
29385-43-1Footnote a Tolyltriazole 1H-Benzotriazole, 4(or 5)-methyl-
36437-37-3 UV-350 Phenol, 2-(2H-benzotriazol-2-yl)-4-(1,1-dimethylethyl)-6-(1-methylpropyl)-
70321-86-7 UV-234 Phenol, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)-
80595-74-0 Not available 1H-Benzotriazole-1-methanamine, N,N-bis(2-ethylhexyl)-5-methyl-
94270-86-7Footnote a Not available 1H-Benzotriazole-1-methanamine, N,N-bis(2-ethylhexyl)-ar-methyl-
Benzothiazoles 95-31-8a TBBS 2-Benzothiazolesulfenamide, N-(1,1-dimethylethyl) HTML Meet one or more of the criteria Refer to the proposed risk management approach
95-33-0 CBS 2-Benzothiazolesulfenamide, N-cyclohexyl-
120-78-5 MBTS Benzothiazole, 2,2'-dithiobis-
149-30-4 MBT 2(3H)-Benzothiazolethione
2492-26-4 SMBT 2(3H)-Benzothiazolethione, sodium salt
  4979-32-2 DCBS 2-Benzothiazolesulfenamide, N,N-dicyclohexyl-
a

This CAS is an unknown or variable composition, complex reaction products, or biological materials (UVCB).

Return to footnote a referrer
Timelines
Date Activity
March 8, 2025 Publication of the final assessment. The Risk Management Approach for 2-Mercaptobenzothiazole (MBT) and its Precursors (from the Benzotriazoles and Benzothiazoles Group) was also published for a 60-day public comment period. The related notice was published in the Canada Gazette, Part I, Vol. 159, No. 10.
June 24, 2023 Publication in Canada Gazette, Part I, of a notice under section 71 of the Canadian Environmental Protection Act, 1999 (CEPA).
March 6, 2021 Publication and start of 60-day public comment period on the Draft Screening Assessment for the Benzotriazoles and Benzothiazoles Group (including follow-up activities for TBBS, CBS, MBTS, MBT, SMBT, and DCBS) and the Risk Management Scope for 2-Mercaptobenzothiazole (MBT) and its Precursors. The related notice was published in the Canada Gazette, Part I: Vol. 155, No. 10.

Additional considerations

Although TBBS, CBS, MBTS, MBT, SMBT and DCBS are not considered to be harmful to human health at current levels of exposure, these substances are associated with effects of concern. Therefore, there may be a concern to human health if exposures were to increase. For this reason, these substances may be considered in future initiatives to track their commercial status or identify new uses or exposures. Monitoring of MBT in surface water and sediment which is planned as part of the ecological component of the performance measurement evaluation will also help track human exposures. Prior to monitoring, analytical methods will need to be developed.

Information gathering

Section 71 CMP 2023

In June 2023, a notice was published in the Canada Gazette, Part I: Vol. 157, No. 25 – June 24, 2023 under section 71 of CEPA. This notice applies to 11 benzothiazole substances. More information is available on the information gathering with respect to certain substances under the CMP web page.

Background

Two other substances were identified as being part of the Benzotriazoles and Benzothiazoles Group at the outset of the third phase of the CMP. These substances (CAS RNs 80584-90-3 and 21564-17-0) were subsequently determined to be of low concern to both human health and the environment through other approaches. The conclusion for CAS RN 80584-90-3 is provided in the Final Screening Assessment for Substances Identified as Being of Low Concern using the Ecological Risk Classification of Organic Substances and the Threshold of Toxicological Concern (TTC)-based Approach for Certain Substances. The conclusion for CAS RN 21564-17-0 is provided in the Final Screening Assessment for the Rapid Screening of Substances with Limited General Population Exposure.

Page details

Date modified: