Impacto da esterilização nas propriedades físicas e na barreira bacteriana de embalagens SMS: análise comparativa baseada nas normas ABNT para validação em serviços de saúde

Abstract

Spunbonded-Meltblown-Spunbonded (SMS) is recognized as a safe material for packaging health care products during the sterilization process. Although it is recommended for single use, there is a lack of conclusive evidence proving its unsuitability for reuse. The aim of this study was to evaluate the ability of SMS packaging to maintain its bacterial penetration resistance and physical properties after a second moist heat sterilization process. The properties were assessed through dry bacterial penetration resistance testing, in accordance with ABNT NBR 14920, and wet bacterial penetration resistance testing, following ABNT NBR 15622. The maintenance of sterility over time was evaluated after storage periods of 3 and 6 months. Tensile strength and elongation were tested according to ABNT NBR 13041. The SMS mesh condition was examined using scanning electron microscopy (SEM) at magnifications of 100x, 200x, 500x, and 1000x, analyzed with ImageJ software. The statistical analysis of the dry bacterial penetration resistance and long-term sterility maintenance tests was performed descriptively. Repeated measures ANOVA with Tukey’s post-hoc test was used for the statistical analysis of the wet bacterial penetration resistance test. For the tensile strength, elongation tests, and SEM mesh condition evaluation, twoway ANOVA with Tukey’s post-hoc test was applied. No bacterial contamination occurred in the dry test. In the wet test, although contamination was observed, the results were not statistically significant (p>0.05). Statistically significant differences were found between virgin and sterilized SMS from both brands in the tensile strength and elongation tests. Brand A's SMS showed greater degradation after sterilization compared to Brand B, although both brands exhibited failures even before undergoing sterilization. In the long-term sterility maintenance test, all samples remained sterile after 3 months of storage. After 6 months, one sample from each brand—sterilized only once—showed contamination (0.77% contamination rate). SEM analysis revealed structural changes in the materials after sterilization, with different behaviors observed between brands. In Brand A, a decrease in the number of spaces between SMS fibers was observed, while Brand B showed an increase in these spaces. The results of this study suggest that SMS can be reused as packaging for the sterilization of health care products, as it maintains its bacterial barrier. The significant reduction in tensile strength would typically contraindicate reuse; however, considering the inadequacy of virgin SMS, this characteristic requires further investigation. As for elongation, SMS remains suitable for reuse. In addition to the material condition (virgin or sterilized), the commercial brand influences the decision regarding reuse.