PM2064: Emergency Innovation of Personal Protective Equipment During a Pandemic

Background: In the early months of the COVID-19 pandemic, PPE supplies depleted quickly. Medical facilities resorted to reusing PPE and using alternate forms of PPE, without knowing if they were reliable and effective.

Objective:
This project was designed to study emergency reuse and development of PPE, by evaluating fit performance.

Methods: After approval by the OU Institutional Review Board, 49 subjects were recruited from the Health Sciences Center. Each participant was fit-tested in a study mask with the AccuFIT9000™ Quantitative Fit Testing System before and after wearing the mask for up to 7 days. Masks tested: N95s, self-made masks (using high filtration efficiency material), KN95s, and surgical masks.

Results: The Effective Sample Size (ESS) Modified Mann Kendall Test Yue Wang Approach was used to assess the significance of mask fit trend over time.

For N95s, 67% of participants achieved fit factors (FF) ≥100 at baseline, with a significant decline (p = 0.00065) in fit over 7 days.

The self-made masks also showed significant decline (p = 0.0055) over time, but initial testing showed an average overall FF of 32.06 (96.88% protection), which remained >20 (95% protection) through day 3 of wear.

KN95s showed a significant increase in fit trend over time (p value of 0.0055), but the average overall FF was < 10 at initial testing ( < 90% protection).

Surgical masks showed an average overall FF of 3.28 (69.5% protection).

Conclusion: OSHA requires a FF of ≥100 (≤1% face seal leakage, or 99% protection) for N95s. However, N95s are only given an assigned protection factor (APF) of 10, intended for use where ≤90% protection is needed. This 10-fold difference ensures protection remains >90% throughout the work shift. In this study, 33% of N95s did not achieve an initial FF ≥100. The fit of N95s decreased significantly after multiple days of reuse. Even so, all N95s but one achieved an APF >10 (90% protection) for the duration of the study. This study supports reuse of N95s as directed by CDC and FDA.

This study did not demonstrate acceptable fit of KN95s and surgical masks, suggesting they should not be used as PPE in the presence of SARS-CoV-2.

The self-made mask used in this study did not achieve a FF ≥100, but it outperformed the KN95. Emergency Use Authorization would be needed prior to this mask being used in clinical settings, but these results demonstrate promise that alternative masks might be useful if proper materials and designs are used.