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At least 109 records · Page 6Linked to original sources
PubMed1994

Concomitant sensitization to triglycidyl isocyanurate, diaminodiphenylmethane and 2-hydroxyethyl methacrylate from silk-screen printing coatings in the manufacture of circuit boards.

A 48-year-old female silk-screen printer had worked in the manufacture of circuit boards for 12 years before she got the first symptoms of dermatitis on her wrists and lower arms. On the 1st patch test session, epoxy resin and the remainder of the standard series were negative, while a plastics and glues series gave an allergic reaction to 4,4'-diaminodiphenylmethane (DDM). The 2nd test session revealed allergic reactions to several acrylics, several epoxy compounds and 3 ink components. According to the material safety data sheets, 1 ink hardener contained DDM, but the causative agent in 1 ink and 1 ink hardener remained uncertain. The manufacturers of the 2 inks kindly provided us with their components for further patch tests. 2 of these components gave allergic reactions: triglycidyl isocyanurate (TGIC) and 2-hydroxyethyl methacrylate (2-HEMA). Our case report shows that the manufacture of circuit boards involves exposure to highly sensitizing chemicals. DDM, TGIC and 2-HEMA should be remembered as silk-screen printers' potential contact sensitizers in the manufacture of circuit boards.

Aniline Compounds↗
PubMed1996

Occupational sensitization to epoxy resin and reactive diluents in marble workers.

10 out of 22 marble workers handling a bicomponent resin, based on epoxy resin and ortho-cresyl glycidyl ether (CGE), developed contact dermatitis and airborne contact dermatitis within 20 days to 2 months of exposure. All 22 subjects were patch tested with epoxy resin, bisphenol A, epichlorohydrin and a series of reactive diluents. The 10 symptomatic subjects were all positive to the reactive diluent CGE, and 4 of them also to epoxy resin. The other reactive diluents that gave positive reactions were phenyl glycidyl ether (7 cases), cyclohexanedimethanol glycidyl ether (2 cases), 1,6-hexanediol diglycidyl ether (2 cases) and allyl glycidyl ether (1 case). The findings of our study suggest that allergic potential is directly proportional to the electronic charge available, for all electron-rich molecules (solvents, high and low polymers, reagents) that interact with the glycidyl ether group. Lesser, but still noticeable, effects are detected when activation of the glycidyl group is related to the possible formation of intramolecular hydrogen bonds. In practice, the occupational problem was partly solved by changing the type of glycidyl ether.

Adult↗
PubMed2003

The effects of sevelamer and calcium acetate on proxies of atherosclerotic and arteriosclerotic vascular disease in hemodialysis patients.

BACKGROUND: We recently determined that in hemodialysis patients, the use of calcium salts to correct hyperphosphatemia led to progressive coronary artery and aortic calcification as determined by sequential electron beam tomography (EBT) while the use of the non-calcium-containing binder sevelamer did not. Whether the specific calcium preparation (acetate vs. carbonate) might influence the likelihood of progressive calcification was debated. METHODS: To determine whether treatment with calcium acetate was specifically associated with hypercalcemia and progressive vascular calcification, we conducted an analysis restricted to 108 hemodialysis patients randomized to calcium acetate or sevelamer and followed for one year. RESULTS: The reduction in serum phosphorus was roughly equivalent with both agents (calcium acetate -2.5 +/- 1.8 mg/dl vs. sevelamer -2.8 +/- 2.0 mg/dl, p = 0.53). Subjects given calcium acetate were more likely to develop hypercalcemia (defined as an albumin-corrected serum calcium > or =10.5 mg/dl) (36 vs. 13%, p = 0.015). Treatment with calcium acetate (mean 4.6 +/- 2.1 g/day - equivalent to 1.2 +/- 0.5 g of elemental calcium) led to a significant increase in EBT-determined calcification of the coronary arteries (mean change 182 +/- 350, median change +20, p = 0.002) and aorta (mean change 181 +/- 855, median change +73, p < 0.0001). These changes were similar in magnitude to those seen with calcium carbonate. There were no significant changes in calcification among sevelamer-treated subjects. CONCLUSION: Despite purported differences in safety and efficacy relative to calcium carbonate, calcium acetate led to hypercalcemia and progressive vascular calcification in hemodialysis patients.

Acetates↗
PubMed1992

[Synthesis of new antirusty disinfectants. I].

New quaternary ammonium salts [N-alkyl-N-2-hydroxyethyl-N,N-dimethylammonium ethyl phosphate (21, 22), isopropyl phosphate (23), n-butyl phosphate (24) and N-alkyl-N-2-hydroxy-3-phenoxypropyl-N,N-dimethylammonium ethyl phosphate (25, 26), isopropyl phosphate (27), n-butyl phosphate (28) and bis(N-alkyl-N-2-hydroxy-3-phenoxypropyl-N,N-dimethylammonium) malate (29), fumarate (30), succinate (31), adipate (32) and N-alkyl-N-2-hydroxy-3-phenoxypropyl-N,N-dimethylammonium tartrate (33)] were synthesized by alkylation of the corresponding trialkylammonium salts with various epoxy compounds. The new quaternary ammonium salts showed much greater bactericidal activities and antirusting effects than those of benzalkonium chloride. They had also good compatibilities since no precipitate was observed if the solution of any anionic surface active agents were added to the solution of these new quaternary ammonium salts. This property is the same as that of amphoteric surface active agents.

Bacteria↗
PubMed2000

[Epoxy in occupational environment--an old acquaintance in a new dress].

This article describes a cluster of epoxy related contact dermatitis in a glassfibre reinforcement plant, using mostly preimpregnated epoxylaminate (Pre-Preg), but also fluid epoxy-products. An occupational medical and dermatological examination revealed nine of 26 cases as allergic contact eczema, 14 as toxic epoxyrelated eczema and three cases of other non-occupationally related skin diseases. The plant uses seven different epoxyresins with 15 epoxyhardeners. Preventive measures were gradually improved, but even then it was difficult to rule the production into safe procedures with this potent allergen used in large scale production of windmill wings.

Denmark↗
PubMed2000

Field-emission scanning electron microscopy of resin-dentin interface morphology of seven dentin adhesive systems.

PURPOSE: The purpose of this study was to evaluate the resin-dentin interface morphology of 7 resin-based dentin adhesive systems (Solid Bond, EBS-Multi, PermaQuik, One Coat Bond, Gluma One Bond, Prime & Bond NT/NRC, and Clearfil Liner Bond 2V). MATERIALS AND METHODS: Fourteen dentin disks 1.0 mm thick were obtained from superficial occlusal dentin of extracted human third molars, and finished with wet 600-grit silicon carbide paper. Two dentin disks were bonded using each of the adhesives above according to the manufacturers' instructions, and a thin layer of flowable resin composite was applied. The specimens were kept in tap water for 24 h at 37 degrees C, and then assigned to one of two observational techniques: a fracture technique and an acid-base technique. Fracture technique: shallow grooves were cut, fixed in 10% buffered formalin, and dehydrated in an ascending ethanol series up to 100%, critical-point dried, and fractured along the prepared grooves. Acid-base technique: the specimens were embedded in epoxy resin, sectioned through the center, polished with diamond paste down to 0.25-micron particle size, and treated with 10% orthophosphoric acid for 10 s and 5% sodium hypochlorite for 5 min. All the specimens were mounted on aluminum stubs, gold sputter coated, and observed using field-emission scanning electron microscopy (FE-SEM). RESULTS: All the dentin adhesive systems showed hybrid layer formation, but the thickness varied depending on the bonding system used. The self-etching priming systems (Prime & Bond NT/NRC and Clearfil Liner Bond 2V) showed the thinnest hybrid layer at 1 to 2 microns, whereas the "single-bottle" system (Gluma One Bond) exhibited the thickest hybrid layer at 8 to 16 microns. CONCLUSION: The ultramorphological structures of dentin bonding systems are determined by the composition of each system. Characterization of the interface of the adhesive system using the fracture technique provides additional information regarding the pattern of resin infiltration in some dentin bonding systems.

Adhesives↗
PubMed1975

Allergenicity of epoxy-reactive diluents in the guinea pig.

The sensitizer in epoxy resins may be the actual resin, the hardeners, the reactive diluents or the additives. An epoxy-reactive diluent, Epoxide No. 8, recently introduced on the Swedish market, and described by the manufacturer as nonsensitizing was checked for allergenicity by "the guinea pig maximization test". Judging from the results, Epoxide No. 8 in the guinea pig test was even more allergenic than butylglycidyl ether, another reactive diluent known to be a human skin sensitizer. The potential allergenicity of Epoxide No. 8 was also indicated by the fact that butylglycidyl ether, cresylglycidyl ether and epoxy resin elicitated positive reactions in animals sensitized to Epoxide No. 8.

Animals↗
PubMed2002

Stabilization of nontoxic PVC formulation for gamma irradiation sterilization, II. Effect of antioxidants.

In order to investigate the fundamental data for the resistance of gamma radiation sterilization of polyvinylchloride (PVC), the formulations of the antioxidants such as commercial Irganox series and inorganic, processing aids, stabilizer aids, trans-stilbene oxide (StO) and so on have been carried out. The control and irradiated PVC samples with 1.5, 2.5 and 4.0 Mrad were characterized by mechanical tester, colorimetry, and extractant in water. Irganox 1010 was more effective than Irganox 1076 for color changes whereas Irganox 1076 was more effective than Irganox 1010 for the change of extractant. It was also observed the significant diminution of color changes for inorganic antioxidants as CaO and ZnO. Oxidized paraffin wax as lubricant, styrene-methylmetacrylate copolymers as processing aids, and nontoxic debenzoylmethane as secondary stabilizer did not show good stabilization for the irradiation. The new proposed radiation stabilizer in this study, StO, showed the significant improvement of gamma radiation resistance for the plasticized PVC. The possible mechanism could be explained that an epoxy functional group stabilizes effectively the processes of dehydrogenation, the formation of hydroperoxides, and the formation of oxygen containing groups, and the synergetic effects of an epoxy compound are more notable for the prevention of radiation oxidation in the presence of an aromatic group.

Antioxidants↗
PubMed1985

NTP Toxicology and Carcinogenesis Studies of Diallylphthalate (CAS No. 131-17-9) in F344/N Rats (Gavage Studies).

Diallylphthalate is widely used as a crosslinking agent for unsaturated polyesters. Diallylphthalate or diallylphthalate polyester blends are used primarily as plasticizers and carriers for adding catalysts and pigments to polyesters and in molding, electrical parts, laminating compounds, and impregnation of metal castings. Rubber compounds, epoxy formulations, and polyurethane foams may also contain diallylphthalate. Precise figures are not currently available, although annual production of diallylphthalate in the United States is known to exceed 5,000 pounds, and an estimated 57,000 pounds were imported into the United States in 1982. Toxicology and carcinogenesis studies of diallylphthalate (approximately 99% pure) were conducted by administering the test chemical in corn oil by gavage to groups of 50 male and 50 female F344/N rats at doses of 0 (vehicle control), 50, or 100 mg/kg 5 days per week for 103 weeks. The diallylphthalate doses used in the 2-year studies were chosen on the basis of 13-week studies, wherein doses of 200 or 400 mg/kg caused death, reductions in body weight gains, or periportal hepatocellular necrosis and fibrosis in both sexes. Mean body weights and survival of male and female rats administered diallylphthalate were essentially the same as those of the vehicle controls throughout the 2-year studies, although hepatotoxicity was produced in both sexes by the 100 mg/kg dose. Based on the results of the prechronic studies and the effects on the liver in the 2-year studies, the doses used in the 2-year studies were considered to be adequate for carcinogenicity testing. Male and female rats receiving the 100 mg/kg dose of diallylphthalate in the 2-year studies developed chronic liver diseases characterized by periportal fibrosis, periportal accumulation of pigment, and severe bile duct hyperplasia. Pigment accumulation also occurred at the 50 mg/kg dose in both sexes. Diallylphthalate administration increased the occurrence of mononuclear cell leukemia in female rats (P<0.05 by trend tests), and the increase in the 100 mg/kg dose female rats was greater (P</=0.05) than in the vehicle controls by pairwise comparisons (vehicle control, 15/50, 30%; low dose, 15/43, 35%; high dose, 25/49, 51%). An increased occurrence of mononuclear cell leukemia was not observed in male rats receiving diallylphthalate. A previous NTP carcinogenesis study (NTP TR 242) reported an increased incidence of lymphomas in male B6C3F1 mice receiving diallylphthalate by gavage for 2 years at doses of 0, 150, or 300 mg/kg. This increase was considered to be equivocally related to diallylphthalate administration. The incidences of hyperplasia and inflammatory lesions of the forestomach were increased in a dose-related fashion in both sexes of mice in that study, and uncommon forestomach papillomas were observed in 0%, 2%, and 4% of both sexes of mice. Because of the numerical increase in forestomach papillomas, the concomitant presence of forestomach hyperplasia, and the rarity of forestomach papillomas in vehicle control (corn oil gavage) B6C3F1 mice, the development of these proliferative lesions of the forestomach in mice may have been related to diallylphthalate administration. In the current study in rats, a squamous cell carcinoma was found in one high dose male rat. Diallylphthalate was not mutagenic in Salmonella typhimurium strains TA98, TA100, TA1535, or TA1537 with or without activation by a 9,000 x g supernatant fraction from the livers of Aroclor 1254-treated male Sprague-Dawley rats or Syrian hamsters. Diallylphthalate did not induce sex-linked recessive lethal mutations in Drosophila melanogaster. An audit of the experimental data was conducted for these carcinogenicity studies on diallylphthalate. No data discrepancies were found that influenced the final interpretations. Under the conditions of this study, the administration of diallylphthalate by gavage in corn oil to male and female F344/N rats for 2 years caused chronic liver disease characterized by periportal fibrosis and pigment accumulation and an increasetal fibrosis and pigment accumulation and an increased severity of bile duct hyperplasia. The incidence of mononuclear cell leukemia was significantly increased in female rats receiving 100 mg/kg. Because of the variability in the incidence of this neoplasm in aged Fisher 344 rats and the difficulty in definitively diagnosing this lesion in Fisher 344 rats, this increase was considered to be equivocal evidence of carcinogenicity of diallylphthalate in female rats. There was no evidence of carcinogenicity in male rats. Synonym: DAP

Journal Article↗
PubMed1983

NTP Carcinogenesis Bioassay of Diallyl Phthalate (CAS No. 131-17-9) in B6C3F1 Mice (Gavage Study).

Diallyl phthalate is a widely used crosslinking agent for unsaturated polyesters. Diallyl phthalate or diallyl phthalate polyester blends are used primarily as plasticizers and carriers for adding catalysts and pigments to polyesters and in molding, electrical parts, laminating compounds, and impregnation of metal castings. Rubber compounds, epoxy formulations, and polyurethane foams may also contain diallyl phthalate. Annual production of diallyl phthalate in the United States exceeds 5,000 pounds; precise figures are not available. A NTP Carcinogenesis bioassay of diallyl phthalate (99% pure) was conducted by administering 0 (vehicle control), 150, or 300 mg/kg diallyl phthalate in corn oil by gavage, 5 days per week for 103 weeks, to groups of 50 male and 50 female B6C3F1 mice. Survival rates and mean body weights of dosed mice were not different from those of the controls, and pathological lesions unrelated to proliferative changes were not observed. Therefore, a maximally tolerated dose for the purposes of carcinogenicity testing may not have been achieved. The incidences of lymphoma and either lymphoma or leukemia in dosed male mice were no significantly greater than those in the controls according to pairwise comparisons (P=0.051 to P=0.096), but the trend tests were statistically significant by either life table or incidental tumor analysis (P=0.031 to P=0.045). The incidence of lymphomas in the high-dose male mice was 12/50 (24%) in comparison with 6/50 (12%) in the controls. Recent historical incidences at the performing laboratory and in the NTP Bioassay Program were 18/120 (15%) and 71/661 (11%), respectively. Since the incidence of high-dose male mice with leukemia was not significantly greater than that of concurrent or historical controls at the performing laboratory by pairwise comparisons, this marginal increase was considered only to be equivocally related to diallyl phthalate administration. Increased incidences of squamous cell papillomas, hyperplasia, and inflammatory lesions of the forestomach were observed in diallyl phthalate-dosed mice of both sexes in a dose-related manner. Papillomas of the forestomach were observed in 0%, 2%, and 4% of the control, low-dose, and high-dose mice of both sexes. The recent historical incidence of this tumor in gavage control mice from both the performing laboratory and other laboratories within the Bioassay Program was less than 1%. Forestomach hyperplasia was diagnosed in 0%, 15%, and 18%, and in 8%, 2%, and 29% of the control, low-dose, and high-dose male and female mice, respectively; chronic inflammation of the forestomach was diagnosed in 0%, 9%, and 16% and in 4%, 2%, and 18% of the control, low-dose, and high-dose male and female mice, respectively. Because of the numerical elevation of the forestomach papillomas in the high-dose mice of both sexes, the concomitant observation of dose related forestomach hyperplasia, and the rarity of this tumor in corn oil (gavage) control B6C3F1 mice, the development of squamous cell papillomas of the forestomach may have been related to diallyl phthalate administration. Under the conditions of this bioassay, the development of chronic inflammation and hyperplasia of the forestomach in both male and female B6C3F1 mice was considered to be related to the administration of diallyl phthalate. The development of squamous cell papillomas of the forestomach may also have been related to chemical administration, but the available data are insufficient to indicate a clear cause and effect relationship. An increase in the incidence of male mice with lymphomas was observed, but this increase was considered only to be equivocally related to diallyl phthalate administration. The results of this bioassay, therefore, do not indicate that diallyl phthalate is carcinogenic in B6C3F1 mice, although a maximum tolerated dose may not have been achieved. A carcinogenicity study by the National Toxicology Program of diallyl phthalate in male and female Fisher 344/N rats, employing daily gavage doses of 0 (vehicle control), 50, or 100 mg/kg boicology Program of diallyl phthalate in male and female Fisher 344/N rats, employing daily gavage doses of 0 (vehicle control), 50, or 100 mg/kg body weight is currently being evaluated. Levels of Evidence of Carcinogenicity: Male Mice: Equivocal Female Mice: Equivocal

Journal Article↗
PubMed1979

Contact sensitivity to phenylglycidyl ether.

From among 40 workers with dermatitis who did not have contact with phenylglycidyl ether but worked with epoxy resins, 5 were positive to Epidian 5 and phenylglycidyl ether. Cross reactions between these contactants were noted in 3 of the 17 guinea pigs with primary sensitization to epoxy resin or the tested diluent. For 58 persons coming into contact with phenylglycidyl ether the frequency of sensitization to the contactant was determined and the mean period between starting work and the occurrence of dermatitis was calculated.

Animals↗
PubMed1991

[The toxicological hygienic evaluation of the manufacture of epoxy resins based on complex glycidyl ethers].

The workers engaged in the processing of the UP-671, UP-671D, UP-677, UP-680 and UP-682 epoxide resins are influenced by both initial and intermediate industrial products, as well as the resins' volatile components in MAC threshold concentrations. The workers engaged in major professions displayed upper respiratory allergic diseases, contact and allergic dermatitis, sensibilization to epichlorhydrine, staphylococci and kidney allergen. Euthyroid goiter was diagnosed in most workers, along with thriiodothyronine decrease in blood serum and a higher rate of chromosomal aberrations in lymphocytes. The experimental studies performed revealed moderate-degree toxicity in the resins, their cumulation properties, as well as allergenic, irritating, mutagenic and embryotoxic characteristics. Basing on the results of the study, the USSR Health Ministry adopted the working zone air MAC for the resins at the level of 0.5 mg/m3, vapours, 2nd degree of hazardousness.

Adult↗