With the current media interest in Natural Rubber Latex Allergy (also known as Immediate Type Hypersensitivity, Protein Allergy or Type I), it was possibly only a question of time before the focus moved also to Allergic Contact Dermatitis (also known as Type IV, Delayed Hypersensitivity or Chemical Allergy). Indeed with 12% (*1 Gibbon, 2001) of the population potentially affected by allergic contact dermatitis, compared to 0.8% and 7% of the general population for Natural Rubber Latex Allergy (*2 Lebenbom-Mansour, 1997), there is possibly much to be gained from minimizing the risk of Allergic Contact Dermatitis. However it should be noted that the seriousness of the symptoms associated with Allergic Contact Dermatitis are not comparable to those for Natural Rubber Latex, which may explain the level of interest being given to Natural Rubber Latex in the workplace.
In response to the growing interest in Allergic Contact Dermatitis, several glove manufacturers have introduced accelerator-free products. Chemical accelerators such as thiazoles, thiurams and dithiocarbamates are known contact sensitizers. They are used widely in the manufacture of natural rubber latex, nitrile and neoprene gloves. Indeed they often play a vital role in the vulcanization process. Without these chemical accelerators many of the qualities that we seek in natural rubber latex and most synthetic gloves (e.g. barrier performance as demonstrated by tensile strength, elasticity etc) would not be present. In addressing this issue we should be aware that over 2800 chemical agents are known to have the potential to trigger Allergic Contact Dermatitis (*3 Drake, 1995) and therefore these chemical accelerators represent a relatively small proportion of the known chemical allergens. However with over 80% of reported glove-associated Allergic Contact Dermatitis being attributable to chemical accelerators (*4 Heese et al, 1991), the removal of accelerators from gloves does offer the possibility of helping to reduce the prevalence of Allergic Contact Dermatitis.
Cross reference guide to commonly used accelerators
|Tetramethylthiuram Disulphide (TMTD)||Zinc Mercaptobenzothiazole (ZMBT)||Zinc Dibutyldithiocarbamate (ZDBC)|
|Tetramethyl Thiuram Disulphide (TMTM)||Mercaptobenzothiazole (MBT)||Zinc Dimethyldihiocarbamates (ZDMC)|
|Tetraethyl Thiuram Disulfide (TETD)||Benzothiazyl Disulphide (MBTS)||Zinc Diethyldithiocarbamates (ZDEC)|
|Zinc Mercaptobenzimidazole (ZMBI)||Zinc Pentamethylene Dithiocarbamate (ZPMC)|
|Zinc Pentamethylene Dithicarbamate (ZPD)|
Classes of accelerators
Methyl accelerators = ZDMC
Ethyl accelerators = ZDEC
Butyl accelerators= ZDBC
Pentamethylene accelerator= ZPMC