Allergic Contact Dermatitis from Rubber and Plastic Gloves
Robert N. Phalen, Howard I. Maibach in Protective Gloves for Occupational Use, 2023
Epoxy resin monomers are strong skin sensitizers known to cause occupational allergic contact dermatitis. Diglycidyl ethers of bisphenol A and F (DGEBA and DGEBF) are widely used as components in epoxy resin products. Alternative compounds have been designed, synthesized, and assessed for sensitizing potency using in vivo murine local lymph node assay. Studies have shown that the allergenic effects of diglycidyl ethers of bisphenol F (DGEBF) depend on the absence of oxygen in the side chain of the molecule, known as the “terminal epoxide groups.”75 Thus, an epoxy resin that lacks oxygen in the side chain was considered promising and was synthesized. As predicted, the sensitizing potency was reduced by a factor of ten with the removal of the oxygen molecule. The technical properties of the newly synthesized polymer were not considered sufficient. Developing an alternative epoxy material is a delicate balance between allergenic activity and polymerization properties. The use of improved epoxy resin monomers with less skin sensitizing effects is one way to address contact allergy to epoxy resin.76
Ultrastructural Immunocytochemistry
Joan Gil in Models of Lung Disease, 2020
The physicochemical nature of epoxy resins poses obstacles to immunostaining. First, the epoxy medium resists penetration by most staining reagents, particularly those of high molecular weight, because a medium sufficiently inelastic to yield ultrathin sections lacks the porosity needed to allow diffusion of reagents into it. Hydrophobicity of the medium presumably also plays a part in the impenetrability to reagents in aqueous solution. In addition, chemical reagents in the medium, including the oxidants effecting polymerization, adversely affect the antigenicity of cell constituents. The prolonged high temperature required for polymerization of the resin also contributes to denaturation of the antigen.
Contact Urticaria Syndrome from Epoxy Resin
Ana M. Giménez-Arnau, Howard I. Maibach in Contact Urticaria Syndrome, 2014
Epoxy resins are components of an epoxy resin system. Besides epoxy resins there are other components in the epoxy resin system such as curing agents, reactive diluents, modifiers, and additives. The resins and the reactive diluents are epoxy compounds, whereas the other components represent other chemical substances and groups.
Modified self-healing cementitious materials based on epoxy and calcium nitrate microencapsulation
Published in Journal of Microencapsulation, 2021
Fahimeh Farshi Azhar, Aylin Ahmadinia, Alireza Mohammadjafari Sadeghi
Epoxy resin because of its excellent chemical, physical, mechanical and thermal properties, is an effective candidate for healing agent. A wide variety of curing agents such as amines and anhydrides can be used for curing of epoxy resin at different temperatures (Reaz Chowdhury et al. 2015). Also, epoxy resin has the most matches with urea–formaldehyde in microencapsulation. Blaiszik et al. (2009) synthesised microcapsules containing PUF shell containing reactive epoxy resins core with different diluents. The prepared capsules meet the requirements for use in self-healing composites, containing processing survivability, thermal stability and efficient in situ rupture for delivery of the healing agents. Jin et al. (2012) studied the microcapsules comprise of hollow PUF shell and epoxy-amine healing agent. Yuan and Liang (2008) evaluated some effective factors in size and surface morphology of PUF microcapsules containing epoxy resins, such as type and concentration of surfactant, adjusting time for pH value and heating rate. But, in these studies, healing behaviour of the host matrix was not reported. On the other hand, the PUF-epoxy microcapsules have been studied mostly for self-healing in polymer-based composites by now, and few researches have been reported on its utilisation in cementitious materials (Dong et al.2016, Perez et al.2015).
Antimicrobial effectiveness of root canal sealers against Enterococcus faecalis
Published in Biomaterial Investigations in Dentistry, 2022
Paola Castillo-Villagomez, Elizabeth Madla-Cruz, Fanny Lopez-Martinez, Idalia Rodriguez-Delgado, Jorge Jaime Flores-Treviño, Guadalupe Ismael Malagon-Santiago, Myriam Angelica de La Garza-Ramos
Complete removal of microorganisms from the root canal system in all patients is impossible; therefore, filling materials with antimicrobial activity for the root canal are used to reduce microorganisms and prevent infections. On the other hand, many endodontic failures occur after removing necrotic or inflammatory tissue with microorganisms. These tissues need to be retreated and managed with apical surgery; however, filtration failure occurs in 15% to 22% [4]. These complications are attributed to the lack of root canal sealing after endodontic treatment due to the high hydrophobicity and water absorption caused by the solubility of the cement. The development of new ceramic-type materials has improved sealing to reduce this problem. Epoxy resin is widely used as a gold standard, although it still has limitations, such as mutagenicity, cytotoxicity, inflammation, and hydrophobicity. Calcium silicate-based sealers with high biocompatibility and hydrophilicity have also been introduced. Both cements reduce microfiltration thanks to properties in their dynamic environment and being biocompatible in this application [5].
Extensive high-pressure injection injury of the hand due to epoxy resin paint: a case report
Published in Case Reports in Plastic Surgery and Hand Surgery, 2021
Gaku Niitsuma, Hidechika Nakashima, Takushi Nagai, Kenichirou Teramoto, Keikichi Kawasaki, Katsunori Inagaki
The components of epoxy resin paint include a large number of carcinogens, such as toluene (18%); phenol, 4-dodecyl-, branched (9%); xylene (9%); 2-propanol (9%); ethylbenzene (9%); isobutanol (9%); solvent naphtha (petroleum), light arom (0.9%); and Stoddard solvent (0.9%) [9]. Epoxy resin paint has skin corrosive/irritant properties and reproductive toxicity. Remnants could cause cancer due to the presence of toluene and xylene [9]. The physical characteristics of epoxy resin paint include hardening at room temperature. Additionally, it has excellent water- and salt-resistant properties and is often used for painting ships and reinforcing cracks. The fluid cures in 12–24 h and volatilizes toxic substances when it hardens (volatile toxicity), which ends once curing ceases. There is an anticaking agent that is available, but it is tissue-toxic, and its application to tissue during surgery is prohibited [9]. Based on the above characteristics, the best treatment in such cases is to remove the paint before it hardens completely. Thus, we decided to perform a thorough debridement.
Related Knowledge Centers
- Adhesive
- Epoxide
- Ethylene Oxide
- Polymer
- Curing
- Prepolymer
- Cross-Link
- Thiol
- Thermosetting Polymer
- Fibre-Reinforced Plastic