Document VjavRoOvkmakgnZzoLqnBwjmZ

1966 National Safely Congress HAZARDOUS CONDITIONS AND PRECAUTIONARY MEASURES WHEN WORKING WITH EPOXY RESINS AND SOLVENTS By CHARLES W. V/YMAN Senior Staff Engineer, Industrial Hygiene and Safety Engineering, Western Electric Co., Inc., Hawthorne Works, Chicago Epoxy resin systems arc composed of two or more reactive components: nncurrd resin, and a curing agent generally referred to as the ``hardener.'' Uncurcd liquid resins have a consistency of heavy syrup and in this form have limited use; however, when mixed with a hard ener, a chemical reaction takes place which converts it to a hard, mechanically strong material with excellent adhesion, cohesion, chemical, and electrical resistance properties. Other additives to the mix may include liquids or solids to produce desired physical properties. Epoxy resin applications include potting of electrical components, rc-inforccd plastic and metal laminates, foundry patterns, form ing tools and dies, adhesives for metal and plastic bonding, appliance finishes, floor and surface coatings. Let us look at the hazards problems. In the December, 1959, issue of the Amer ican Medical Association's Archives of In dustrial Health, the following statement was made: "Epoxy resins arc causing more oc cupational dermatitis than any other new chemical material within the past 10 years"! The first users of epoxy resins did not appreciate the delayed irritating effect resins and hardeners could have on the skin. Work ers got the material on their hands and arms during mixing, pouring, and spreading o|>crations. Since the irritant has a delayed rather than an immediate effect on most people, a few days to several weeks elapsed before severe eases of skin irritation de veloped. Recent developments of new hardening agents of low toxicity and minimum irritant potential have somewhat reduced the der matitis hazard. However, the use of these new hardeners docs not eliminate the need for following prescribed precautions to avoid contact with the material. Good housekeep ing, personal cleanliness, and ventilation arc still essential. Basic resins, reactive curing agents, reac tive diluents, and modifiers arc. mild to strong primary skin irritants, and some have sensitizing properties. The volatile materials given off during compounding, handling, and curing opera tions can cause irritation of the eyes, upper respiratory tract, ami lungs if the concen tration of the vapors is excessive. No sys temic intoxication of any significance has been associated with exposure to epoxy resins. Contact dermatitis is the common type of skin irritation produced by epoxy resins. The irritation appears at the (xjint of contact and may vary from slight reddening with mild itching to a rash or small eruptions with intense itching. In severe eases there may be open or weeping sores with or with out swelling. I f an employee contracting a mild case of contact dermatitis is removed from the ex posure and receives the necessary medical care, the irritation will usually clear up in a few days and the employee may return to the job without ill effects; that is, if lie is careful to avoid further contact with the irritant. 1severe eases the employee may become temporarily disabled and may or may not be returned to the job. Sensitization dermatitis is the less common type of dermatitis. The term is used to describe an allergic type of reaction from a sensitizing agent. The sensitizing agent may not affect the' individual on first contact, but after continued exposure for an extended licriod a dermatitis suddenly develops. After sensitization occurs, the slightest exposure to the sensitizing agent may precipitate a severe reaction. Irritation may spread from the point of contact to other parts- of the body and be accompanied by swelling and other systemic reactions.