Agent Name
CAS Number
Major Category
Plastics & Rubber
Mercaptobenzothiazole formula graphical representation
2(3H)-Benzothiazolethione; 2-Benzothiazolethiol; 2-Benzothiazolinethione; 2-Benzothiazolyl mercaptan; 2-MBT; 2-Mercaptobenzothiazole; 2-Mercaptobenzthiazole; 2-Mercptobenzothiazole; 2-Merkaptobenzotiazol [Polish]; 2-Merkaptobenzthiazol [Czech]; AG 63; Accel M; Accelerator M; Benzothiazole, mercapto-; Benzothiazole-2-thione; Benzothiazolethiol; Captax; Dermacid; Ekagom G; Kaptaks; Kaptax; Kaptax [Czech]; MBT; Mebetizole; Mebithizol; Mercaptobenzothiazol; Mercaptobenzothiazole; Mercaptobenzothiazole (VAN); Mercaptobenzthiazole; Mertax; Nuodeb 84; Nuodex 84; Pennac MBT powder; Pneumax MBT; Rokon; Rotax; Royal MBT; Soxinol M; Sulfadene; Thiotax; USAF XR-29; Vulkacit M; Vulkacit mercapto; Vulkacit mercapto/C; [ChemIDplus]
Rubber Additives
Yellowish to tan crystalline powder; [HSDB]
Nonrubber sources of exposure include metalworking fluids, antifreezes, greases, anticorrosive agents, adhesives, detergents, and veterinary products. [Marks, p. 101] Allergic contact dermatitis in shoemakers; [Marks] A known skin sensitizer, mercaptobenzothiazole has largely been replaced as an anti-corrosion agent in metalworking fluids. [Kanerva, p. 717] "Metal indicators are organic compounds that form specifically colored metal ion complexes in aqueous media. These dye reactions can be employed for detection of the equivalence point in volumetry (complexometry), as well as for concentration determinations in colorimetry or photometry." 2-Mercaptobenzothiazole is used for the photometric determination of Au, Cd, Cu, Pb, and Pd. [Ullmann] Used in leather tanning; [PMID 21938525]
A rubber accelerator, MBT is the most common cause of shoe allergy and second to the thiurams as the cause of glove contact dermatitis. [Marks, p. 100-2] An eye irritant; May cause skin sensitization; [ICSC] Mice show severe liver damage after high-dose feeding for 1 week; [AIHA] See "Carcinogenicity of some industrial chemicals," Volume 115. [IARC, News Release, 23 February 2016]
Biomedical References

Exposure Assessment

4 mg/m3 (inhalable fraction), 1.5 mg/m3 (respirable fraction)
Vapor Pressure
0.000464 mm Hg
Odor Threshold Low
2 ppm
Lethal Concentration
LC50 (rat) > 1,270 mg/m3
Explanatory Notes
Flash point = 392 deg F; Odor threshold from CHEMINFO;
5 mg/m3

Adverse Effects

Skin Sensitizer
Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion
IARC Carcinogen
Probable (2a)

Diseases, Processes, and Activities Linked to This Agent


Occupational diseases associated with exposure to this agent: