Contact allergy to allergy to allyl glycidyl ether present as an impurity in 3‐glycidyloxypropyltrimethoxysilane, a fixing additive in silicone and polyurethane resins

Abstract

We present a 43-year-old man who worked in the plastics industry and who suffered from an occupational dermatitis on the hands and forearms. He was found to be allergic to an epoxy silane compound that was contaminated with allyl glycidyl ether, a reactive epoxy diluent. HPLC analysis and patch testing indicated that this impurity was probably the only sensitizer. Moreover, the gloves used provided absolutely no protection, as the inner side also generated strong positive reactions.

Occupational exposure to alkoxysilanes in a fibreglass manufacturing plant

“…We concluded that both methods were suitable and equally sensitive for assaying 3-methacryloxypropyltrimethoxysilane. For 3-glycidoxypropyltrimethoxysilane, the LC method proved to be more valid, and the sensitivity was found to be at the same level as in an earlier study with this silane reported by Dooms-Goossens et al (1995). The GC method was necessary for the analysis of 3-aminopropyltriethoxysilane in the occupational hygiene samples, because of the dierences in the sensitivity between the LC and GC methods.…”

“…Furthermore, we had the opportunity to test only two silanes, 3-methacryloxypropyltrimethoxysilane and vinyltrichlorosilane, in two sizing mixtures for their possible permeation. There is sucient evidence available from a case study showing that 3-glycidoxypropyl-trimethoxysilane was able to penetrate the polypropylene plastic gloves worn by a worker (Dooms-Goossens et al 1995). The workers in our survey wore mostly PVC gloves made by dierent manufacturers.…”

“…As far as we are aware there are no data concerning possible percutaneous absorption of organosilanes. However, the reported cases about organosilane-induced skin sensitisation (Dooms-Goossens et al 1995;Heino at al. 1996;Tooletto et al 1994), and the overall irritating properties of the silanes alone gave the reason to investigate dermal exposure to these compounds.…”

“…The authors concluded that the presence of amino-functional methoxysilane in the coating mixture favoured sensitisation to the epoxy resin. A synthetic impurity of 3-glycidoxypropyltrimethoxysilane, allyl glycidyl ether, was found to be the source of contact allergy in a case report from the plastics industry (Dooms-Goossens et al 1995).The exposure of workers to endotoxin, phenolic compounds and formaldehyde in a ®breglass manufacturing plant has been evaluated (Milton et al 1996), but there are no data concerning exposure to silanes.…”

Minimizing the Risks of Missing a Contact Allergy

“…This is the case, for example, for cetyl alcohol (pharmaceutical quality), which contains an unidentified impurity, so patch tests with analytical-quality cetyl alcohol thus give a ‘false’-negative reaction [26, 27]. Of course, allergenic impurities occur much more in industrial products; for example, allylglycidylether, a reactive epoxy thinner, was found as a contaminant in a fixation additive in silicon and polyurethane resins [28]. Allergenic degradation products can also be formed during storage and then primarily by oxidation, as is the case of limonene [29].…”