Mercaptobenzothiazoles

Evaluation of mercaptobenzothiazoles with regard to the effect of allergy on the reduction of the ability to work:

• Mercaptobenzothiazole and its derivatives are considered as a unit, since a corresponding allergy usually extends to the whole group. They are used as vulcanization accelerators, corrosion inhibitors, flotation agents and fungicides. Possible sources of allergens are: synthetic rubber products, adhesives, antifreeze, cooling lubricants, fungicides, bactericides, paints and photographic films.
• The incidence of positive test results is about 1-2%.
• Important sources of allergens: protective gloves, synthetic rubber soles.
• Mercapto-mix and mercaptobenzothiazole are tested in the epicutaneous test, as the mercapto-mix test does not detect 30% of cases with MBT allergies. On the other hand, 12% of the cases react against mercapto-mix, which had shown negative reactions against MBT. The percentage of false negative results when testing MBT or mercapto-mix alone is about 30-40%. Therefore the combination of both test substances increases the accuracy to 70-80%.
• Relevant occupational exposures: Leather workers, construction workers, health service. Exposure cannot be avoided in the shoe and rubber industry, especially in the production and handling of tyres and rubber moulded articles. Workplaces in these areas are to be considered closed.
• Effect of an allergy: As a rule, "minor", in case of a high degree of sensitization a "medium" effect can be assumed, but should be specifically justified.

The German Contact Allergy Group has so far tested mercaptobenzothiazole 2% in vasliene. This corresponds to the recommendations of the ESCD (European Society of Contact Dermatitis). MBT 2% in vaseline is no longer available in Germany as a test preparation. Insofar the DKG now recommends a 1% application form.

1. Diepgen TL et al. (2005) Evidence-based assessment of the effect of type IV allergies in the reduction of earning capacity - assessment of occupational skin diseases. Dermatologist 56: 207-223
2. Diepgen TL, Dickel H, Becker D, John SM, Geier J, Mahler V, Rogosky E, Schmidt A, Skudlik C, Wagner E, Weisshaar E, for the working group "Evaluation of allergens in BK 5101" of the Working Group for Occupational and Environmental Dermatology in the German Dermatological Society (2008) Assessment of the effect of allergies in the reduction of earning capacity in the context of BK 5101: Thiurams, mercaptobenzothiazoles, dithiocarbamates, N-isopropyl-N'-phenyl-p-phenylenediamine. Evaluation of the effects of allergies on the reduction in earning capacity in the context of BK 5101: thiurams, mercaptobenzothiazoles, dithiocarbamates, N-isopropyl-N'-phenyl-p-phenylenediamines]. Dermatol Occupation Environment 56: 11-24
3. Geier J et al (2016) News on the epicutaneous test series of the German Contact Allergy Group. Dermatology at work and in the environment 64: 70-75