A comparative analysis of <i>in vitro</i> cytotoxicity across various glove types using four different methods

The coronavirus disease 2019 (COVID-19) pandemic has led to increased use of protective materials among healthcare workers and the general population, resulting in a rise in health issues such as allergies. Glove types, such as latex, nitrile, and vinyl, are notable sources of cutaneous reactions; however, most of their cytotoxic effects are considered negligible. Given the significant exposure of healthcare professionals to gloves and the absence of mandatory toxicological testing to ensure the quality of these medical products under Brazilian legislation, this study aimed to evaluate the <i>in vitro</i> cytotoxicity of three glove-types: natural rubber latex (NRL) surgical, nitrile, and vinyl medical examination gloves, using mouse fibroblast L-929 cell cultures. Four methods were employed based on guidelines from the United States Pharmacopeia (USP), Brazilian Pharmacopeia (BP), the Organization for Economic Cooperation and Development (OECD) and the International Organization Standardization (ISO). All latex gloves tested would be considered unsafe for use, exhibiting at least moderate cytotoxicity in the agar diffusion, direct contact and elution test methods. In contrast, 75% of nitrile gloves and 67% of vinyl gloves were considered safe, showing mild cytotoxicity in the agar diffusion method, which proved to be the most effective for differentiating cytotoxicity among glove materials. Both nitrile and vinyl gloves showed significantly lower cytotoxicity than latex gloves in the promising Neutral Red Uptake (NRU) method. These findings support the recommendation for mandatory inclusion of the agar diffusion and elution test methods as regulatory quality control assays for evaluating glove cytotoxicity.