Fit factor compliance of masks and FFP3 respirators in nurses: A case-control gender study

To determine the fit factor and compliance with American Industrial Hygiene Association (AIHA) and Occupational Safety and Health Administration (OSHA) requirements of surgical masks and filtering respirators in male versus female nurses.

A case-control gender study performed from 2016 to 2019.

A gender and age matched-paired sample of 74 nurses was recruited and divided into men (n = 37) and women (n = 37). FFP3 filtering respirators and surgical masks fit factors were compared between male and female nurses by Mann-Whitney U tests. These measurements were tested to pass or fail according to the OSHA (≥100) and AIHA (≥50) criteria by Fisher exact tests for a 95% confidence interval.

Global fit factor mean (standard deviation) was 2.86 (2.73) and 3.55 (6.34) for male and female nurses wearing surgical masks (p = .180), respectively, and nobody passed neither OSHA nor AIHA criteria (p = 1.00). Nevertheless, global fit factor were 30.82 (28.42) and 49.65 (43.04) for male and female nurses wearing FFP3 respirators, respectively, being significantly lower and worse in male nurses (p = .037). According to OSHA criteria, only 2.70% and 13.51% of male and females nurses, respectively, passed with non-significant difference (p = .199), meanwhile 21.62% and 48.64% of male and female nurses, respectively, passed AIHA criteria showing significant differences (p = .027) wearing FFP3 respirators.

All male and female nurses wearing surgical masks failed to pass OSHA and AIHA criteria. Global fit factor of the proposed FFP3 filtering respirators was decreased and worse in male than female nurses.

Our recommendation is to avoid surgical masks use for protective purposes and use the proposed FFP3 filtering respirators among nurses. Each nurse should be fit tested for its own respirator with special caution in male nurses due to their lower fit factor achieved and most of them failed to pass OSHA and AIHA criteria, especially during COVID-19 pandemic.