Occupational dermatitis to epoxydic and phenolic resins

ARTICLE

Auteur(s) : Christian Geraut¹, Dominique Tripodi¹, Béatrice Brunet-Courtois¹, Fabrice Leray², Laurent Geraut¹

¹Service des maladies professionnelles CHU Nantes, Hôtel Dieu, 44093 Nantes cedex 1, France
²Laboratoire interrégional de chimie de l’ouest, Département Prévention Risques Professionnels, CRAM Nantes

accepté le 21 Janvier 2009

Occupational contact dermatoses are the most frequent forms of contact dermatitis and their occurrence raises concerns of diagnosis, prevention and prognosis [1, 2]. Plastics in the form of epoxydic and phenolic resins are handled in very many trades and sometimes involve epidemic dermatitis in certain companies. Dermato-allergists are sometimes at a loss faced with the multiplicity of suspected products and the complexity of the chemical formulas of the products handled. The allergic dermatoses to epoxydic and phenolic resins are often the most serious of the dermatoses to plastics and they remain common, although their compensation by law in the tables for occupational diseases has been envisaged for a long time in France.

Occupational and other exposure

These resins have exceptional properties of hardness and impact resistance to heat, water and many chemicals. They also have important properties of adhesiveness on many materials (metals, plastic, rubber, wood, glass, ceramics, concrete) and of electric insulation [4]. Their implementation requires the use of two components: the hardener is added to the resin just before the application, reticulation is carried out at ambient or hot temperatures and the reaction is exothermic. Some of them have more particular characteristics: fireproofing properties of the brominated epoxy resins, good electrical insulation of the epoxy-hydantoin resins, better chemical resistance and performance with the high temperatures of the epoxy-novolaque resins.

Epoxy resins are mainly used for:

• – adhesives and coatings for the car, electronics and aeronautics industries, articles of sport (skis, bicycles…), but also do-it-yourself [5];
• – run resins for the manufacture of models and moulds (foundry, manufacture of various objects, prostheses, mountings for glasses, manufacture of resin utensils and capsules;
• – composite materials, very much used in aeronautical engineering [4, 7, 8] (in a pre-impregnated form with glass fibers, plastic fabrics in plates, carbon fiber), being used for manufacture of articles of sport and leisure (tennis rackets, skis, fishing rods) [6]. Certain epoxydic resins are used for competitive boats or prototypes, but are becoming more and more widely used (for example for sailboards) [4];
• – coatings: paintings and varnish, frontage coatings, road coatings, anti-corrosive protection of metal tanks, cisterns and swimming pool coatings, manufacture of electronic components (credit cards, printed circuits), coil insulation and wires, impermeable concrete for pipes or tanks, protection of the ground and walls against chemicals, printing inks… [9-11].

Epoxy resins are also used as histological fixers in electronic microscopy and in immersion oils for optical microscopy [12-14].

Epidemiology

Epoxy resins are primarily allergens of professional origin. Studies on populations consulting for suspicion of occupational dermatitis in general find higher rates of positivity. In a study carried out on 1559 patients tested for suspicion of allergic contact eczema, Holness and Nethercott [15] highlighted that 3.7% had positive tests with epoxy resins. In the group of patients with occupational contact eczema, 11.7% had positive tests with the epoxy resins.

Thus, epoxy resins represent the third most frequently responsible allergen for occupational allergic contact eczemas, after chromates and the rubber allergens. These allergies to epoxydic resins are thus by far the first cause of dermatitis among workers with plastics. The allergies sometimes occur in epidemics where one finds 40 to 60% of workmen affected [4].

The responsibility of the various types of plastics can be evaluated through the statistics from the center of occupational dermatology in Nantes: in 186 cases of occupational dermatitis to plastics, 108 were due to epoxydic resins, 30 to glass fibres, 21 to acrylates and methacrylates, 15 to phenol-formol resins, 6 to urea-formol resins, 6 to polyester resins, 2 to polyurethanes and finally 2 to poly chloroprenes (neoprenes). The epoxy resins thus represent the first cause of cutaneous allergy to coating materials [4]. They are also the principal allergen in the electronics industry [11]. The construction industry is also at risk of allergy to epoxy resins [9]. In the interpretation of these results, it is important to note that the positivity of the studied patch test corresponds only to the epoxy resin of DGEBA type used in the standard battery.

One can also refer to 62 cases seen in the same department between 2001 and 2008. The professional gestures, the products handled and the clinical aspects of the lesions were analyzed with precision. Results: the building and public works professions lead with 18 cases, including 13 allergic eczemas to epoxydic resins, mainly in painters, users of concrete treated with epoxy resin and construction workers, the remainder corresponding to tank or plaster manufacturers, with an allergy to a melamine formol resin in this activity. Nautical construction suffers equally from these cases, with 18 observations in plastic workers, including 8 cases of airborne dermatitis from epoxy resins in users of adhesives. The aircraft industry arrives in 3rd position with 14 cases, including 6 workmen manufacturing special pipes, 4 painters, 2 fitters, 1 caster and 1 aeronautical carpenter allergic to phenol-formol resins. The other various cases are 3 coil winders manufacturing electric motors, 2 foundry workmen (with allergy to a resin melamine-formol), 1 caster, 2 carriage-builder painters, 2 workmen manufacturing printed circuits, 1 woman allergic to a phenol-formol resin used to stick shoes and 1 artist allergic to epoxy.

Contact urticarias

Clinical demonstrations

Airborne dermatitis

These airborne dermatoses are often very acute, pruriginous and oozing [21, 22]. Jolanski [23] found facial involvement in 60% of patients having a contact dermatitis to epoxy resins. An isolated attack on the face is rare but possible. In a sensitized subject, lesions can appear at the time of only a slight and fleeting contact with the allergen, such as a passage through a workshop where epoxy resins are handled [19, 20]; the contact can be cutaneous, (hands, gloves) or airborne, some compounds being volatile (reactive thinners, hardeners) [42].

Eczema with localised allergic contact

Prognosis

Irritation dermatitis

The epoxy resins of DGEBA type have an irritating capacity which decreases with the increase in the molecular weight of the oligomer. In 843 cases of irritation contact dermatitis at work, Jolanski [23] reports 5 cases (0.6%) secondary to composite epoxy resins.

Contact urticaria [23, 27]

Other contact urticarias have been blamed on the following substances:

• – epoxy resins based on DGEBA;
• – reactive thinners (PGE and CGE);
• – anhydrides of acids (MHHPA, MTHPA, Pa);
• – aliphatic polyamine hardeners (DETA, TEIA).

Other rarer occupational dermatoses

• – Sclerodermatous lesions with erythema, cutaneous sclerosis and muscular weakness in 6 subjects working with epoxy resin polymerization. The responsibility for an amine was evoked [28];
• – Polymorphic erythema [29];
• – Lichenoid dermatitis [30];

Practical tests with the European or International Standard Battery

The chemical formula of this resin: it belongs to the group of thermohardening plastics i.e. plastics which harden by reticulation during the reaction of a resin precomposed with a hardener or catalyst, with an exothermic reaction. The basic component is epichlorhydrine, having the epoxydic function of binding to bisphenol A to produce a diglycidylether bisphenol A [31].

The epoxy resins thus contain at least 2 strongly reactive epoxy groups, brought by the two epichlorhydrine molecules [32].

For this reason, their chemical name will always include the “epoxy” term or “glycidyl”. More than 75% of the epoxy resins are manufactured starting from the polycondensation of epichlorhydrine with bisphenol A, forming a mixture of monomers of diglycidyl ether of bisphenol A (DGEBA) with a molecular weight of 340 Dalton (Da) and oligomers of a higher molecular weight [33].

Value of patch tests included in the standard battery

Nevertheless, epoxy resins based on DGEBA with a raised molecular weight are sensitizing because they contain from 0.2 to 15% of monomer 340 Da [33]. Epoxy resins of DGEBA type having a low molecular weight (350-400 Da) are liquid, with sometimes very high rates (approximately 90%) of DGEBA monomers, whereas those of higher molecular weights (> 900 Da) are solid, with lower rates of DGEBA monomers (up to 15% and more) [31]. Kanerva et al. [34] investigated 182 patients with an allergic contact eczema to the epoxy resins over a period of 22 years. 146 patients out of 182 (80%) were allergic to epoxy resins of the DGEBA type; 35/182 patients (approximately 20%) had negative tests with the DGEBA standard resin epoxy used in the standard battery, but positive results with other composites of epoxy resins.

It appears obvious that this simple test of the standard battery is not sufficient in the event of negativity and that the practice of specialized complementary batteries is essential [35].

Use of specialized batteries

They form glycidylic ethers of a general formula [31-33].

The more the molecular weight is raised, the less the resin is allergenic. The molecular weight of bisphenol A diglycidylether is 340, whereas that of the polymer obtained is at least 624 [36].

Resins available in specialized commercial batteries

DGEBF

The resin Epikote 862 is an epoxy resin of low viscosity obtained starting from Bisphenol F and epichlorohydrine. It is used in construction and various industries like the production of adhesives, mortars... Ponten and Bruze [37] report a frequency of allergy to DGEBF slightly higher than that to DGEBA (study of 23 cases of allergy to epoxy resins among 299 patients tested for suspicion of eczema of allergic contact); Jargot underlines the increase in the use of the DGEBF in many epoxydic resins [38]. In a German multicentric study, reactions crossed with DGEBA and DGEBF were frequently observed [39]. This is available at a concentration of 0.25%.

Cycloaliphatic epoxy

Triglycidylisocyanurate

Epoxyacrylates

Thinners of resins

The reactive thinners contain strong sensitizing chemicals, mainly phenyl glycidylic ether, cresyle glycidylic ether or butanediol diglycidylic ether [49-51]. There is no cross reaction between reactive DGEBA and thinners. On the other hand, cross reactions are possible between the reactive thinners and the cycloaliphatic epoxy resins [52].

Allyl- and butyl- glycidyl ether is available at a concentration of 0.25%. Cresyl glycidyl ether is available at a concentration of 0.25%; isopropylglycidyl ether is not available to our knowledge [53].

2-Phenyl glycidyl ether (C9H10O2) dilutes reactive epoxy resin. It forms chemical bonds with the resin during treatment and accelerates the process. It is available at a concentration of 0.25%.

Trimethylolpropane triglycidylether (C15H25O6). Use: Thinner used to reduce the viscosity of epoxy resins. Available at a concentration of 0.25%.

1,6-Hexanediol diglycidylether (C12H22O4). Use: in the production of epoxy resin-like thinners to decrease viscosity. Available at a concentration of 0.25%.

1,4-Butanediol diglycidylether (C10H18O4). Available at a concentration of 0.25%.

Finally it is advisable to indicate that the epoxydic resins are often mixed with other sensitizing resins which should be tested: urea-formol or phenol-formol.

Resins not currently available in commercial batteries

Brominated epoxy

Dimethylhydantoine epoxies (very effective in their adhesion to fibres, in particular the new fibres, Kevlar polyparaaramides, and their resistance to electric arcs) [40].

Other epoxy resins not derived from DGEBA which are also sensitizing do not appear in the commercial batteries.

Polyfonctional epoxy

To be tested, these two products must be preserved in the freezer and tested in acetone at 20%.

Their formulas are as follows:

In the presence of new resins of unknown or vague composition, chromatography can be used to highlight the presence of particular compounds which could be tested.

Hardeners

Resin hardeners are often responsible for dermatitis because of their caustic character, in particular certain amino hardeners, which then secondarily support a sensitization with the resin epoxy itself (irritation “prepares the ground” for the allergy).

Polyamine hardeners of low molecular weight are strong sensitizing agents:

• – Jolanki et al. [44] explored 182 patients with an allergic contact eczema to epoxy resins over a 22 year period: 42/182 (23%) were allergic to polyamine hardeners.
• – The most commonly used hardeners are the basic hardeners like triethylenetetramine, (C6H18N4) Available at a concentration of 0.5%.
• – Diethylenetriamine (C4H13N3). Solvent for the intermediaries of the organic synthesis of resins and a hardener for epoxy resins. Available at a concentration of 1%.
• – Triethanolamine, (C6H15NO3). Available at a concentration of 2%.
• – Hexamethylene tetramine (C6H12N4). Used in the production of phenolformaldehyde resins. Available at a concentration of 2%.
• – Ethylenediamine, (C2H10Cl2N2). Available at a concentration of 1%.
• – Isophoronediamine, (C10H22N2). A common hardener of epoxy resins [54]. Available at a concentration of 0.1%.
• – Diaminodiphenylmethane, an agent binding in resins Available at a concentration of 0.5%.
• – Aminophenols, (3 and 4 aminophenols). m-Xylylenediamine (C6H12N2). Synonym: 1,3-(a) (aminomethyl) benzene. Use: Intermediary used in the production of epoxy resins as a hardener. Taking into account the manufacturing process, this intermediary is not found in the finished product. The handling of these intermediate agents is carried out only in the professional environment. Available at a concentration of 0.1%.
• – 3 (Dimethylamino) propylamine. Available at a concentration of 1%.

The polyamine hardeners most frequently positive are the MDA, the DETA and IPDA [55, 56].

The positivity of certain tests does not necessarily mean an allergy to composites of the epoxy resins. Thus, sensitizing with ethylenediamine can be due to an exposure to cutting fluids, cosmetics or rubber, which contain it. In the same way, sensitizing to diaminodiphenylmethane can correspond to an allergy to an amine as a para (for example: para-phenylenediamine) [58].

The other non-polyamine hardeners are much more rarely implicated in allergic contact eczema: some rare cases with anhydride dodecenyisuccinic, anhydride methylhexahydrophtalic and dicyanodiamide have occurred [56].

Allergic reactions to the other components are rarer:

• – In the study by Jolanski; 1 case in 182 was of allergy to hardeners containing phtalic anhydride [55, 56], available at a concentration of 0.5%.

Other additivies [57]

• – Dimethyl phthalate; available at a concentration of 5%;
• – Di-n-butylphtalate; available at a concentration of 5%, classified as toxic for reproduction, category 2;
• – Dietthylphthalate; available at a concentration of 5%;
• – Ethylhexylphthalate; available at a concentration of 5%, classified as toxic for reproduction, category 2;
• – Triphenylphosphate; available at a concentration of 5%;
• – Tricresylphosphate; available at a concentration of 5%.

Solvents: there is often irritation dermititis to resin solvents which precede or accompany allergic reactions. Indeed, resins are frequently diluted in solvents where the solubilizing action of the coating lipoacide of the skin is more or less marked [59]. Toluene is frequently found, (classified toxic for reproduction, category 3) and xylene, ethylglycol, isopropanol, carbinol, ethyl or methyl acetates, acetonitrile, tetrahydrofuranne, methylisobutylketone, or methylethylketone, not forgetting acetone, which is caustic unless frequent hand washing is performed [60].

The manufacture of these plastics involves using extenders (pine oils, tar), products to render it more flexible, and additives. The additives can be mineral (silica, carbon fibers, classified by the International Cancer Research Center as cancerogenic category 1, in the forms of silica crystalline, quartz, talc, graphite, glass fibers, pulverulent metals…) or others (wood powders, tar, pitch, bituminizers…).

Prepared tests with the products handled

The practice of tests carried out with products brought by the patients

Can solid plastic be tested?

In rare cases there is no reaction to the various types of resins used and the hardener tested separately: however the subject is certain that the lesions appear only with work; then the two mixed products (resin + hardener) should be tested. An allergic reaction then sometimes appears, probably related to the presence of intermediate amines which are formed at the time of the reaction. This test must be made with prudence to avoid any caustic effect. In the same way, one should not test the pure hardener, as is too often seen, with the risk of very strong caustic reactions [62].

Must one consider an “epoxy-mix” test?

Dermatitis due to glass fibers

The aspect can, more rarely, be that of an eczema nummulaire, an appearance of folliculitis, a worsening of telangiectases, urticaria or linear cuttings [59].

The open-test is an examination carried out on the upper internal face of the forearm. It consists of lightly rubbing the skin with glass fiber. When it is positive, this test causes the appearance of papules either immediately (in 15 minutes, the time of histamine release), or with delayed-action (approximately an hour after the test). When clinical symptomatology appears, the professional gestures are a sufficiently evocative diagnosis, the open-test is not essential. In fact, generally, the cutaneous phenomenon disappears in 2 to 3 days, and only 5 to 10% of subjects continue to be troubled. These often have impressive scratching lesions [63, 64].

Advice for individual preventive measures includes wearing gloves, fully covering clothing, (closed at the wrists, the ankles and neck, quite distinct from their town clothes), and taking of showers without friction following exposure. However, the main effort needs to be to design workplaces provided with effective aspiration systems and with a water curtain making it possible to avoid the dissemination of dust in the processing atmosphere.

Dermatitis to phenolic resins

The “plastics” battery includes the following allergens:

• – Similar phenoplast resins and their components;
• – Phenol formaldehyde resin 1%, Resorcin formaldehyde resin 5%, Paratertiaire butylphenol formaldehyde1%, Paratertiaire butylcatechol 1%;
• – Resins. Toluene sulphonamide formaldehyde resin 10%;
• – Components: 2-4-dinitrophenol 1%, Hydroquinone 1%, N-dimethyl-p-toluidine 2%, Resorcinol monobenzoate 1%.

The powder resins polymerize thanks to basic catalyst actions (hexamethylene tetramine, irritating and sensitizing) and the adhesive or resin liquids are polymerized by the addition of acids and hardeners irritating for the skin, like the hydrochloric acid or paratoluenesulfonic acid.

In this reaction amines intervene, which are able to sensitize (triethylamine, ethylamine, methylamine, triethylene diamine, etc.). One also frequently adds pigments (cobalt or chromium salts or oxides) which are able to sensitize.

Very often, the dermato-allergist does not know the precise chemical composition of these secondary reagents, whose secrecy is kept by the manufacturer, and requires the help of a chemistry laboratory. In all cases, it is advisable to carry out the patch tests with a very diluted product (0.5 to 2% in water).

As for other plastics, various solvents and thinners can have an irritating effect on the skin (toluene, xylenes, chlorinated solvents…).

Prevention in plastic workers

It is necessary to insist on the gestures to be avoided or abandoned: not applying resins and their hardeners to naked hands, not washing the hands with solvents or to rubbing skin covered with glass fiber. Emollient creams make it possible for the skin to recover the water lost at the time of the chemical aggressions.

Medical Prevention [3] relies on early treatment with dermocorticoides, applied in effective amounts (i.e. weak), on emollient creams for the symptomatic treatment of irritative contact dermatitis, and associated with the suppression of the allergen and irritating factors. It is essential to inform the patient of all the sources (professional and other) of contact with the epoxy resin compounds, in order to avoid the repetition or the perpetuation of the problem, which risks evolving to a persisting autonomous eczema.

The study of Castelain et al. [7] clearly shows the effectiveness of prevention measurements (at the same time technical and medical) in the aviation sector. The evaluation of cases of allergy to epoxy resins over two periods (1955-1965 and 1981-1990) after the installation of a prevention scheme, shows a fall from 19 to 3 cases of allergy to epoxy resins.

Compensation

• – in the general list of occupational diseases, Social security n° 51 “Occupational diseases caused by epoxydic resins and their components”, for epoxy resins and their components;
• – under article n° 15 (a) “Allergic mechanisms affected by the aromatic amines, their salts…” for the amino aromatic ones;
• – under article n° 49 “Affections caused by aliphatic and alicyclique amines” for the aliphatic amines. Irritative dermatitis with aromatic amines can be also declared under article n°15.

Conclusion

The dermato-allergist sometimes has difficulty finding the composition of the various plastics handled by a user, who often has very little idea of the exact nature of products which he uses. The commercial batteries are often behind on technical progress and must thus be supplemented by tests developed by the dermato-allergist himself, with the assistance of chemists and while taking care to avoid caustic effects by using suitable dilutions.

Acknowledgements

References

2 Diepgen TL, Kanerva L. Occupational skin diseases. Eur J Dermatol 2006; 16: 324-30.

3 Crepy MN. Dermatoses professionnelles aux résines époxy. Documents pour le médecin du travail, 2002, 91, 297-306.

4 Géraut C (ED). L’essentiel des pathologies professionnelles. Médecine du Travail Ellipses, 1995.

5 Holness DL. Outbreak of allergic contact dermatitis caused by epoxy resin in a gluing and swaging operation. Am J Contact Dermatitis 1992; 3: 150-4.

6 Jolanski R, Tarvanen K, Tatar T, Estlander T, et al. Occupational dermatoses from exposure to epoxy resin compounds in a ski factory. Contact Dermatitis 1996; 34: 390-6.

7 Castelain PY, Com J, Castelain M. Occupational dermatitis in the aircraft industry 35 years of progress. Contact Dermatitis 1992; 27: 311-6.

8 Bruze M, Edenholm M, Engström K, Svensson G. Occupational dermatoses in a swedish aircraft plant. Contact Dermatitis 1996; 34: 336-40.

9 Van Putten PB, Coenraads P, Nater JP. Hand dermatoses and contact allergic reactions in construction workers exposed to epoxy resins. Contact Dermatitis 1984; 10: 146-50.

10 Conde-Salazar L, Gonzalez de domingo MA, Guimaraens D. Sensitization to epoxy resin Systems in special flooring workers. Contact Dermatitis 1994; 31: 157-60.

11 Tucker SC, English JSC. The electronics industry. In: Kanerva L, Elsner F, Wahlberg JE, Maibach HL, eds. Handbook of occupational dermatology. Berlin, Heidelberg, New-York: Springer-Verlag, 2000.

12 Le Coz C, Coninx D, Van Rengen A., El Aboubi S, et al. An epidemie among laboratory technicians of occupational contact dermatitis from a reformulated immersion oil for microscopy. In: Kanerva L, Lauerma A, Björkner F., Estlander T, Jolanki R, Hannuksela M, eds, Proceedings of the fourth congress of European Society of Contact Dermatitis: People and Work. Research Reports, 1998, 18, p. 86.

13 Geraut C, Tripodi D. Airbome contact dermatitis due to Leica immersion oil. Int J Dermatol 1999; 38: 676-9.

14 Crepy MN, Bazire A, Bayeux-Dunglas MC, Cohen-Jonathan AM, et al. Immersion oils for microscopy. A new source of occupational eczema. Ann Dermatol Venerol 2000; 127: 210-21l.

15 Holness DL, Nethercott JR. Resuts of testing with epoxy resin in an occupational health clinic population. Am J Contact Dermatitis 1992; 3: 169-74.

16 Schnuch A, Geer J, Uter W, et al. National rates and regional differences in sensitization to allergens of standard series. Population-adjusted frequencies of sensitization (PAFS) in 40 000 patients from a multicenter study (NDK). Contact Dermatitis 1997; 37: 200-9.

17 Seidenari S, Manzini BM, Danese P, et al. Patch and prick test study of 593 healthy subjects. Contact Dermatitis 1990; 23: 162-7.

18 Kanerva L, Tokkanen J, Jolanski R, Estlander T. Statistical data on occupational contact urticaria. Contact Dermatitis 1996; 35: 229-33.

19 Géraut C. Affections cutanées liées à la mise en œuvre des matières plastiques. In: Résines synthétiques, durcisseurs et additifs: risques toxicologiques et surveillance en Médecine du Travail. APREMALAT, 2001: 57-67.

20 Bouchet L. Dermatoses aux résines époxydiques: à propos de 74 observations vues à la Consultation de Pathologie Professionnelle de Nantes. Thèse de Médecine de Nantes, 1990, 123 p.

21 Tosti A, Guerra L, Toni F. Occupational airborne contact dermatitis due to epoxy resin. Contact Dermatitis 1988; 19: 220-2.

22 Cleenewerk MB, Marin P, Lheureux M. Problèmes cutanés observés lors du moulage des matières plastiques. Lett GERDA 1991; 8: 10.

23 Jolanski R, Estlander T, Kanerva L. Occupational contact dermatitis and contact urticaria caused by epoxy resins. Acta Derm. Venereol. Supplementum (Stockholm) 1987; 134; 90–4.

24 Hogan DI, Dannaker CJ, Maibach HL. The prognosis of contact dermatitis. J Am Ac 1990; 23: 300-7.

25 Rosen RM, Freeman S. Prognosis of occupational contact dermatitis in New South Wales, Australia. Contact Dermatitis 1993; 29: 88-93.

26 Kanerva L, Bjorkner B, Estlander T, Jolanski R, et al. Plastic materials: occupational exposure, skin irritancy and its prévention. In: Van Der Valk PGM, Maibach HL, eds. The irritant contact dermatitis syndrome, CRC Press. Boca Raton: New-York, 1996: 127-55.

27 Sasseville D. Contact urticaria from epoxy resin and reactive diluents. Contact Dermatitis 1998; 38: 57-8.

28 Yamakage A, Ishikawa H, Saito Y, Hattori A. Occupational scleroderma-like disorder occuring in men engaged in the polymerization of epoxy resins. Dermatologica 1980; 161: 33-4.

29 Whitfeld MJ, Rivers JK. Erythema multiforme after contact dermatitis in response to an epoxy sealant. J Am Acad Dermatol 1991; 2S: 386-8.

30 Lichter M, Drury D, Remlinger K. Lichenoïd dermatitis caused by epoxy resin. Contact Dermatitis 1992; 26: 275.

31 Foussereau J. Guide de dermato-allergologie professionnelle. Masson, 1991; (452 p. 118-130).

32 Foussereau J, Benezra C, Maibach H. Occupational contact dermatitis. Clinical and chemical aspects. Munksgaard 1985; 452: 216-37.

33 Bost J. Résines éthoxyliques. Matières Plastiques-Chimie Applications Technique et Documentation, Paris, 1980, pp. 45-61.

34 Kanerva L, Jolanski R, Tupasela O, et al. Immediate and delayed allergy to diglycidyl ether bisphenol A epoxy resin. Contact Dermatitis 1990; 23: 252.

35 Holness DL, Nethercott JR. The performance of specialized collections of bisphenol A epoxy resin System components in the evaluation of workers in an occupational health clinic population. Contact Dermatitis 1993; 28: 216-9.

36 Fregert S, Trulson L. Simple methods for demonstration of epoxy resins of bisphenol A type. Contact Dermatitis 1978; 4: 69-72.

37 Ponten A, Bruze M. Contact allergy to epoxy resin based on diglycidylether of bisphenol F. Contact Dermatitis 2001; 44: 98-9.

38 Jargot D, Blachère V, Cassebras M, et al. Mise en évidence de dérivés glycidyliques de bas poids moléculaire dans les résines époxydiques. Cahiers de Notes Documentaires -Hygiène et Sécurité au travail. INRS 1994; 157: 443-50.

39 Geier J, Lessmann H, Hillen U, et al. An attempt to improve diagnostics of contact allergy due to epoxy resin systems. First results of the multicentre study. EPOX, 2002.

40 Fahri R, Morel C, Cheron J. Matières plastiques et adjuvants. Hygiène et Sécurité. INRS, 1998; (ED 638,229 p).

41 Géraut C. Annexe C Répertoire des autres principaux allergènes. In: Lachapelle JM, Frimat P, Tennstedt D, Ducombs G, eds. Dermatologie professionnelle et de l’environnement. Masson, 1992: 337-41; (372 p).

42 Jolanski R, Kanerva L, Estlander T, Tarvainen K. Concomittant sensitization to triglycidyl isocyanurate, diaminodiphenyl-methane and 2-hydroxyethyl methacrylate from silk-screen printing coatings in the manufacture of circuit boards. Contact Dermatitis 1994; 30: 12-5.

43 Geier J, Lessmann H, Uter W, Schnuch A. Are concomitant patch test reactions to epoxy resin and bis-GMA indicative of cross-reactvity? Contact Dermatitis 2007; 6: 376-80.

44 Jolanski R. Occupational skin diseases from epoxy compounds. Epoxy resin compounds, epoxy acrylates and 2,3-epoxypropyl trimethyl ammonium chloride. Acta Derm Venereol Supplementum 1991; IS9: 1-80.

45 Tennstedt D, Jacobs MC, Lachapelle JM. Guide introductif à la batterie standard européenne des tests épicutanés et à ses ajouts. Gerda: Médiscript éd., 1995.

46 Van Joost T, Rosyanto ID, Satyawan I. Occupational sensitization to epichlorohydrin (ECH) and bisphenol-A during the manufacture of epoxy resin. Contact Dermatitis 1990; 22: 125.

47 Estlander T, Jolanski R, Henricks-Eckerman ML, Kanerva L. Occupational contact allergy to bisphenol A. Contact Dermatitis 1999; 40: 52-3.

48 Kaddar N, Harthé C, Déchaud H, Mappus E, Pugeat M. Cutaneous penetration of bisphenol A in pig skin. J Toxicol Environ Health 2008; 8: 471-3.

49 Prens EP, De Jong G, Van Joost T. Sensitization to epichlorhydrin and epoxy System components. Contact Dermatitis 1986; 15: 85-90.

50 Géraut C. Toxicité des résines époxydiques. Encyclopédie Médico-Chirurgicale (Paris France). Intoxications Pathologie du travail, 16541 A30, 9-1990, 3p.

51 Kanerva L, Jolanski R, Estlander T. Allergie contact dermatitis from non-diglyciclyl-ether of bisphenol A epoxy resins. Contact Dermatitis 1991; 24: 293-300.

52 De Groot AC. Occupational contact allergy to alpha-naphtyl-glycidyl ether. Contact Dermatitis 1994; 30: 253-4.

53 Géraut C, Séroux D, Dupas D. Allergies cutanées aux nouvelles molécules des résines époxydiques. Arch Mal Prof 1989; 50: 160-1.

54 Cleenewerk MB. Allergènes professionnels émergents. In: Progrès en dermatoallergologie. Montrouge: John Libbey Eurotext, 2005.

55 Conso F, Lejeune X. Toxicité des durcisseurs des matériaux plastiques. Editions techniques Encycl. Méd. Chir. (Paris France). Toxicologie Pathologie professionnelle 16540-C-10, 1992, 2p.

56 Kanerva L, Jolanski R, Estlander T. Allergic contact dermatitis from epoxy resins hardeners. Am J Contact Dermatitis 1991; 2: 88-97.

57 Kelterer D, Bauer A, Elsner P. Spill-induced sensitization to isophoronediamine. Contact Dermatitis 2000; 43: l10.

58 Kanerva L, Estlander T, Jolanski R. Occupational allergic contact dermatitis caused by 2,4,6-tris-(diméthylaminomé1hyl) phénol, and a review of sensitizing epoxy resin hardeners. Int J Dermatol 1996; 35: 852-6.

59 Géraut C, Dupas D. Dermatoses dues aux matières plastiques et aux colles. Rapport présenté aux XXII^es Journées Nationales de Médecine du Travail. Première Rencontre Européenne, Nantes 5 juin 1992. Archives des Maladies Professionnelles 1993; 54: 322-6.

60 Géraut C, Dupas D, Mokhtari R. Les dermatoses dues aux résines époxydiques: expérience franco-algérienne Communication présentée aux XXII^esJournées Nationales de Médecine du Travail. Première Rencontre Européenne, Nantes 5 juin 1992. Archives des Maladies Professionnelles, 1993; 54: 352-3.

61 Tarvainen K, Jolanski R, Estlander T, Tupasela O. Immunologic contact urticaria due to airborne methyl hexahydrophthalic and methyltetrahydrophthalic anhydride. Contact Dermatitis 1995; 32: 204-9.

62 Frimat P, Santoni S. Où en est l’allergie professionnelle aux plastiques. Progrès en dermato-allergologie John Libbey Eurotext 2000 233-244.

63 Bjorkner B. Plasticizers and other additives in synthetic polymers. In: Kanerva L, Elsner R, Wahlberg JE, Maibach H, eds. Handbook of Occupational Dermatology. Berlin, Heidelberg, New-York: Springer-Verlag, 2000.

64 Jolanki R, Kanerva L, Estlander T, Tarvanen K. Skin allergy caused by organic add anhydrides. In: Amin S, Lahti A, Maibach HL, eds. Contact urticaria syndrome. New York: CRC Press, LLC, Boca Raton, 1997.

65 Géraut C, Pellerin O, Certin JF. Pertinence de la batterie « plastiques, colles, résines » en dermato-allergologie professionnelle 16^e cours du GERDA Arcachon, 1995, Médiscript éditeur, 267 p., 157–66.

66 Géraut C, Tripodi D. In: Le suivi des ordonnances de prévention dans les dermatoses professionnelles d’origine chimique. Progrès en dermato-allergologie GERDA. Marseille: John Libbey Eurotext, 1997: 171-84.

67 Géraut C, Tripodi D. Prévention des dermatoses professionnelles. Rev Prat 2002; 52: 1446-50.

68 Mc Clan DC, Storrs FJ. Protective effect of both a barrier cream and a polyethylene laminate glove against epoxy resin, glycerylmonothioglycolate, frullania and tancy. Am J Contact Dermatitis 1992; 3: 201-5.