Tensile properties and integrity of clean room and low-modulus disposable nitrile gloves: a comparison of two dissimilar glove types

Evaluating the Protective Effectiveness of Rubber Glove Materials Against Organic Solvents Upon Repeated Exposure and Decontamination

Background

Glove reuse poses risks, as chemicals can persist even after cleaning. Decontamination methods like thermal aeration, recommended by US OSHA, vary in effectiveness. Some studies show promising results, while others emphasize the importance of considering both permeation and tensile strength changes. This research advocates for informed glove reuse, emphasizing optimal thermal aeration temperatures and providing evidence to guide users in maintaining protection efficiency.

Methods

The investigation evaluated Neoprene and Nitrile gloves (22 mils). Permeation tests with toluene and acetone adhered to American Society for Testing Materials (ASTM) F739 standards. Decontamination optimization involved aeration at various temperatures. The experiment proceeded with a maximum of 22 re-exposure cycles. Tensile strength and elongation were assessed following ASTM D 412 protocols. Breakthrough time differences were statistically analyzed using t-test and ANOVA.

Results

At room temperature, glove residuals decreased, and standardized breakthrough time (SBT)2 was significantly lower than SBT1, indicating reduced protection. Higher temperature decontamination accelerated residual removal, with ΔSBT (SBT2/SBT1) exceeding 100%, signifying restored protection. Tensile tests showed stable neoprene properties postdecontamination. Results underscore thermal aeration's efficacy for gloves reuse, emphasizing temperature's pivotal role. Findings recommend meticulous management strategies, especially post-breakthrough, to uphold glove-protective performance.

Conclusions

Thermal aeration at 100°C for 1 hour proves effective, restoring protection without compromising glove strength. The study, covering twenty cycles, suggests safe glove reuse with proper decontamination, reducing costs significantly. However, limitations in chemical-glove combinations and exclusive focus on specific gloves caution against broad generalization. The absence of regulatory directives on glove reuse highlight the importance of informed selection and rigorous decontamination validation for workplace safety practices.

Evaluation of the risk of occupational exposure to antineoplastic drugs in healthcare sector: part I - medical gloves

Antineoplastic drugs (ADs) are essential tools in cancer treatment, but their cytotoxicity poses a risk to workers involved in their handling. In a hospital environment fundamental strategies for minimising exposure involve proper use of safety cabinets and closed-circuit transfer devices, along with personnel training and increased awareness of risks. However, medical gloves remain the first line of defence. In this respect the evaluation of glove materials and best choices can improve hospital safety management and prevent potential hazards and long-term consequences. The aim of this study was to assess contamination of gloves in samples taken from AD administration and preparation units of nine Italian hospitals and to raise awareness of the importance of evaluating chemico-physical properties of gloves. Our findings show that 33 % of the analysed gloves were positive for at least one AD, with contaminations ranging from 0.6 to 20,729 pg/ cm2. We proposed the alert glove values (AGVs) for each AD as a limit value for contamination assessment and good practice evaluation. Our findings also point to multiple AD contamination (43 % of positive findings in preparation units), calculated as total AGV (AGV-T), and confirm that gloves should be replaced after 30 min of AD handling, based on cumulative permeation and area under the curve (AUC), to maintain safety and limit dermal exposure.

Evaluation of the effects of repeated disinfection on medical exam gloves: Part 2. Changes in mechanical properties

Many healthcare professionals have been forced, under acute shortages, to extend medical exam gloves beyond their intended single use. Despite limited available literature, the CDC proposed a set of guidelines for repeated exam gloves use, indicating a maximum number of treatments for three widely available disinfectants. This study examines how these treatments affect the mechanical properties of latex and nitrile gloves. Furthermore, an acceptability threshold is proposed for changes in tensile property, specifically elastic modulus, as an indication of degradation. This proposed criterion was also applied to similar studies available in the literature to determine applicability and aid in recommendation development. Three different latex glove brands and three nitrile brands were exposed to repeated treatments of an alcohol-based hand rub, diluted bleach, or soap and water. Tensile tests of samples cut from untreated and treated gloves were performed to assess the change in elastic modulus induced by each treatment. The findings suggest that latex gloves performed well within the CDC recommended guidelines of six repeated treatments for an ethanol-based hand rub and 10 repeated treatments of either dilute bleach or soap and water. Nitrile exam gloves, on the other hand, showed significant changes in elastic modulus, with more inconclusive results among brands. This was especially true for treatment with dilute bleach and soap and water. Further research is needed to investigate the effects of disinfection products on the mechanical integrity of nitrile exam gloves. The results support the use of five repeated treatments of ethanol-based hand rub for nitrile exam gloves, a lower threshold than currently recommended by the CDC. This research also supports that the CDC recommendation of 10 repeated treatment with soap and water is appropriate for latex exam gloves, but not for nitrile exam gloves. Occupational safety and health professionals involved in the selection of disposable exam gloves for infection control should consider the compatibility of the glove polymer type with available disinfectants, especially if extended use with repeated disinfection becomes necessary.

Stability of nitrile and vinyl latex gloves under repeated disinfection cycles

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission by fomites is one of the main concerns of coronavirus disease 2019, the World Health Organization advised on the use of protective gloves for handling contaminated surfaces and fomites. The shortage in the supply of personal protective equipment (PPE) due to the surging demand in conjuncture with the disposal of an unprecedented quantity of contaminated PPE into the landfill led to an interest for alternative platforms for the management of PPE. In this study, we evaluated the potential of reusing gloves after repeated disinfection cycles using six readily available and common sterilization methods: UV, ethanol, heat, steam, bleach, and quaternary ammonium compounds (quats) for the inactivation of SARS-CoV-2. For this, two commercially available medical-grade gloves, i.e. nitrile and vinyl (polyvinyl chloride) gloves were tested. Both types of gloves showed deterioration in mechanical and thermal performance with the use of quats as sterilization treatment while no remarkable change in properties was observed up to 20 cycles of disinfection for the other sterilization methods. The exceptions were that the vinyl and nitrile gloves did not tolerate steam/dry heat and UV treatment over 10 cycles due to likely dehydrochlorination and thermal degradation, respectively. Subsequent rounds of sterilization caused no significant change in the glass transition temperature (T_g) of either medical gloves; however, quats caused a slight reduction in T_g due to its plasticizing effect. Overall, the physical sterilization treatments including steam, dry heat, and UV allowed the gloves to retain their thermomechanical performance up to ten cycles of sterilization.

Chemical permeation of similar disposable nitrile gloves exposed to volatile organic compounds with different polarities Part 2. Predictive polymer properties

A follow-up study evaluated the chemical and physical parameters of 10 disposable nitrile glove products in association with the observed variability in chemical permeation performance. The aim was to determine which polymer properties explained or were predictive of the observed wide variation in breakthrough time and steady state permeation rate. The physical and mechanical properties evaluated were thickness, area density, volume fraction and modulus 50-100%. The chemical composition properties evaluated were relative acrylonitrile content, relative carboxylation content, oily plasticizers, inorganic fillers and organic polymer content. A combination of correlation and multiple regression analyses were performed to evaluate the predictive nature of these parameters. For the regression analyses, stepwise, forward selection and backward elimination methods were used to determine an optimal regression fit. Both thickness and area density were strongly correlated with the breakthrough time. With the addition of volume fraction, these factors accounted for about 88-89% of the variation in breakthrough times. The correlation results for the steady-state permeation rate were largely inconclusive and only a moderate correlation with thickness was observed with one solvent. However, regression analyses revealed a moderate to strong association (R² = 0.742; p < 0.001) between the permeation rate and thickness and volume fraction. With the inclusion of volume fraction in all regression models, the microstructure of the polymer played a critical role in chemical permeation, which requires further investigation. Based on these results, selection based on the availability of chemical permeation data for the product should always be preferred, especially when skin protection is critical. When chemical resistance ratings are based on general performance data, additional factors such as thickness and area density should be taken into consideration. In general, increases in thickness and area density are associated with increases in breakthrough time and decreases in the steady-state permeation rate. However, evidence in the literature and this study support the need for inclusion of additional factors associated with the microstructure of the polymer.

Glove permeation of chemicals: The state of the art of current practice-Part 2. Research emphases on high boiling point compounds and simulating the donned glove environment

This second part of the review of the 21st century literature on glove permeation is divided into the following major themes; permeation data and mathematical models, exposure/risk assessment, and manufacturer data. The major issues in the literature were the demonstrations that increasing temperature and applying forces increased permeation; and that glove manufacturer data were sometimes not reproducible. Double gloving of disposable gloves was found to be effective in resisting chemical permeation for short periods of time. Harmonization of standards and commercial glove classifications were called for at conditions that were closer to the temperature and applied forces actually present in the workplace, including whole glove testing and quantitative rather than just qualitative criteria. More research was recommended in each section and subsection with particular emphasis on defining the efficiency of solid phase collection devices, and more data in areas like exposure to cosmetics, household products, liquid foods, drinks, and cleaning liquids. More research in exposure assessment for permeated chemicals with sensors on the inner glove surface and on the skin was called for. Finally, it was decided that the state of the art of current practice was in a situation that needed the permeation standards, research, and the permeation charts of glove manufacturers to be at conditions that better reflected those encountered by workers with donned gloves.

Effect of multiple alcohol-based hand rub applications on the tensile properties of thirteen brands of medical exam nitrile and latex gloves

Current CDC guidance for the disinfection of gloved hands during the doffing of personal protective equipment (PPE) following the care of a patient with Ebola recommends for multiple applications of alcohol-based hand rub (ABHR) on medical exam gloves. To evaluate possible effects of ABHR applications on glove integrity, thirteen brands of nitrile and latex medical exam gloves from five manufacturers and two different ABHRs were included in this study. A pair of gloves were worn by a test operator and the outside surfaces of the gloves were separately treated with an ABHR for 1-6 applications. Tensile strength and ultimate elongation of the gloves without any ABHR treatments (control gloves) and gloves after 1-6 ABHR applications were measured based on the ASTM D412 standard method. In general, tensile strength decreased with each ABHR application. ABHRs had more effect on the tensile strength of the tested nitrile than latex gloves, while ethanol-based ABHR (EBHR) resulted in lesser changes in tensile strength compared to isopropanol-based ABHR (IBHR). The results show that multiple EBHR applications on the latex gloves and some of the nitrile gloves tested should be safe for Ebola PPE doffing based on the CDC guidance. Appropriate hospital staff practice using ABHR treatment and doffing gloves is recommended to become more familiar with changes in glove properties.