Medical Problems Associated with Epi-Oxide Resins

Abstract

THE PROBLEMS ASSOCIATED with the manufacture and use of synthetic resins have received considerable attention in the literature (Harris 1953) but with each new introduction there are fresh problems in the form of toxic reactions from those who handle the materials. Some years ago our main problem was the handling of formaldehyde and phenol compounds. Experience of the risks involved resulted in elimination of practically all the dangers in their handling. Recently the introduction of an entirely new group of compounds has resulted in many new cases of dermatitis. These compounds, known as Epi-oxide resins, have been found to be extremely useful products for many purposes in engineering and other trades. It is doubtful if in the polymerised end product they have sensitising properties but it is necessary to use catalysts or curing agents with them which are definitely irritants and which have been shown to be markedly sensitising. (Since writing the above I have had other cases including a man who has become not only sensitive to the catalysts but also to the finished resin. He reacted immediately with generalised paraesthesia, pruritus . of exposed skin, followed by oedema of the eyelids, drowsiness and diarrhoea even after short exposures of up to 20 minutes in a laboratory where the resin was being machined.) The catalysts for this series are polyamines, some of which have been in use for many years. At the recent Xlth International Congress of Industrial Medicine held in Naples (September, 1954) the section which dealt with the toxicity of plastic compounds did not produce any information of the compounds although it was well known that considerable trouble had been experienced in the United States. It was mentioned in one paper (Bourne, 1954) as a warning of the difficulties which may be met with in the uncontrolled use of polyamine catalysts. This group of resins is of value because of its capacity for adhesion to many materials, e.g., woods, plastics and glass, and appears to be invaluable for many laminating specifications. The resulting products are exceptionally strong and durable and are very light in weight. As casting resins they have many uses and for surface coating appear to have a future. As was expected with such valuable compounds their use has spread rapidly, and there have been reports of a considerable number of cases of dermatitis, particularly in the early trials in industry. The amines recommended by one maker are: diethylenetriamine, dimethylaminopropylamine, dimethylaminomethylphenol, diethylaminopropylamine, benzyldimethylamine, piperdine, diethylamine, pyridine, dicyandiamide. Another maker recommends Hardener 951. This is either tri-ethylenetetramine or a very closely related compound and is in fairly common use. The effects of some of the amines have been well reported, e.g., pyridine is known to be narcotic in high concentration and may cause loss of consciousness. Repeated exposure to low concentration appears to cause disturbance of the central nervous system and gastro-intestinalcomplaints. It has been suggested that these toxic reactions may be due to impurities and as it is unlikely that the commercial products used in industry will be pure, symptoms are to be expected. Related compounds such as meta-para-phenylenediamine may produce exophthalmia and also an acute form of dermatitis. The amine compounds of benzine, toluol, and xylol are well known as being dangerous when used in industry and exceptional care has to be taken in their use. I have been associated with the use of T.E.T. for at least 5 years and recently had occasion to supervise its use in association with the newer resins. Hitherto, it had been mixed with other compounds in the chemical laboratory and then distributed in small quantities up to 2 oz for use as a paint or an adhesive for small surfaces in the manufacture of electronic apparatus. Under