(1) In this issue of EHP, investigators report that pregnant women living near banana plantations in Costa Rica have elevated urinary levels of ethylene thiourea
(ETU), a metabolite of mancozeb.
The answer is that the rubber industry relies heavily on thiourea accelerators, primarily ethylene thiourea
, for the vulcanisation of polychloroprene in the production high-performance rubber, but the material has been declared "toxic for reproduction" under the controversial Reach chemicals legislation.
The sulfur-based crosslinking agents are sulfur, pipentamethylenethiuram tetrasulfide, zinc-N-dibenzyl-dithiocarbamate, N,N'-diphenyl thiourea, ethylene thiourea
and dibenzothiazyl disulfide, sulfur silanes, sulfur siloxanes, and chlorothio sulfonamides.
Generally, thiourea-based accelerators are used in the vulcanisation of polychloroprene rubber - primarily ethylene thiourea
, as it produces the highest performance rubber cure system.
Mancozeb and metiram both rapidly degrade to form ETU (ethylene thiourea
), a carcinogen of some concern.
EBDCs are absorbed by skin, mucous membranes, and respiratory and gastrointestinal tracts, and metabolized via hepatic microsomal enzymes to produce ethylene thiourea
(ETU) (Houeto et al.
In combination with Vanox ZMTI, in either a peroxide or ethylene thiourea
(ETU) cure system, the synergistic effect is said to be evident in the increased state of cure and improved heat resistance.
It is well known that CR compounds cured with zinc oxide and ethylene thiourea
or its derivatives absorb water to a considerable degree as a result of the in situ production of the very deliquescent zinc chloride.
EBDCs are a common class of fungicides (e.g., mancozeb, maneb) that are metabolized to ethylene thiourea
(ETU) in workers after primarily dermal absorption.
Several carefully conducted studies have examined the carcinogenicity of the industrial chemical ethylene thiourea
(ETU) (Chhabra et al.