Reprocessing filtering facepiece respirators in primary care using medical autoclave

Reprocessing filtering facepiece respirators in primary care using medical autoclave: prospective, bench-to-bedside, single-centre study

Harskamp, Ralf E. (Amsterdam UMC)
van Straten, Bart (TU Delft Medical Instruments & Bio-Inspired Technology; Van Straten Medical)
Bouman, Jonathan (Amsterdam UMC)
van Maltha-van Santvoort, Bernadette (Amsterdam UMC)
van den Dobbelsteen, J.J. (TU Delft Medical Instruments & Bio-Inspired Technology)
van der Sijp, Joost Rm (Haaglanden Medical Center; GreenCycl)
Horeman, T. (TU Delft Medical Instruments & Bio-Inspired Technology)

2020

OBJECTIVE: There are widespread shortages of personal protective equipment as a result of the COVID-19 pandemic. Reprocessing filtering facepiece particle (FFP)-type respirators may provide an alternative solution in keeping healthcare professionals safe. DESIGN: Prospective, bench-to-bedside. SETTING: A primary care-based study using FFP-2 respirators without exhalation valve (3M Aura 1862+ (20 samples), Maco Pharma ZZM002 (14 samples)), FFP-2 respirators with valve (3M Aura 9322+ (six samples) and San Huei 2920V (16 samples)) and valved FFP type 3 respirators (Safe Worker 1016 (10 samples)). INTERVENTIONS: All masks were reprocessed using a medical autoclave (17 min at 121°C with 34 min total cycle time) and subsequently tested up to three times whether these respirators retained their integrity (seal check and pressure drop) and ability to filter small particles (0.3-5.0 µm) in the laboratory using a particle penetration test. RESULTS: We tested 33 respirators and 66 samples for filter capacity. All FFP-2 respirators retained their shape, whereas half of the decontaminated FFP-3 respirators showed deformities and failed the seal check. The filtering capacity of the 3M Aura 1862 was best retained after one, two and three decontamination cycles (0.3 µm: 99.3%±0.3% (new) vs 97.0±1.3, 94.2±1.3% or 94.4±1.6; p<0.001). Of the other FFP-2 respirators, the San Huei 2920 V had 95.5%±0.7% at baseline vs 92.3%±1.7% vs 90.0±0.7 after one-time and two-time decontaminations, respectively (p<0.001). The tested FFP-3 respirator (Safe Worker 1016) had a filter capacity of 96.5%±0.7% at baseline and 60.3%±5.7% after one-time decontamination (p<0.001). Breathing and pressure resistance tests indicated no relevant pressure changes between respirators that were used once, twice or thrice. CONCLUSION: This small single-centre study shows that selected FFP-2 respirators may be reprocessed for use in primary care, as the tested masks retain their shape, ability to retain particles and breathing comfort after decontamination using a medical autoclave.

primary care
public health
respiratory infections

http://resolver.tudelft.nl/uuid:d0bd802d-320f-4480-a7ea-0260a7e7a413

https://doi.org/10.1136/bmjopen-2020-039454

2044-6055

BMJ Open, 10 (8)

Institutional Repository

journal article

© 2020 Ralf E. Harskamp, Bart van Straten, Jonathan Bouman, Bernadette van Maltha-van Santvoort, J.J. van den Dobbelsteen, Joost Rm van der Sijp, T. Horeman