Skip to main content
letter
. 2020 May 18;125(3):e319–e322. doi: 10.1016/j.bja.2020.05.008

Table 1.

Comparison of Powered Air-Purifying Respirator and N95 mask respirator.2,5,7,10 HEPA, high-efficiency particulate air; PAPR, powered air-purifying respirator

Powered Air-Purifying Respirator (PAPR) N95 mask respirator
Protection (airborne) Assigned protection factor 25–1000
99.97–100% test particles filtered
HEPA filtered air
Highest level of protection for aerosol-generating procedures
Assigned protection factor 10
95%/97%/99.97% test particles filtered depending on type of N95 mask
Area of coverage Half and full face models, and hoods that cover head or neck and shoulders or all three Nose, mouth, chin
Fit testing Not required (except for some half-face models; e.g. CleanSpace™)
Can be worn with facial hair
Required (costly, labour-intensive)
Facial hair or features may preclude satisfactory fit
Training Longer and regular training
Pre-use check, donning/doffing sequence
Minimal training once fit-tested, disposable, and no set-up required
Risk of self-contamination During donning/doffing Increased risk if extended use or reuse
Availability and cost Limited availability
Initial cost high
High stock and easily accessible
High cost if stockpiling/high use
Supply and maintenance Reusable
Battery recharging
Require supply of filters
Large storage space required
Disposable with ‘extended use’ and ‘limited reuse’ in certain circumstances
Supply rapidly depleted when demand is high
Hospitals urged to stockpile
Air flow and breathing Positive inside to outside air flow
Cooling effects
Less respiratory effort needed
No entrainment of outside air
Negative pressure devices
Increases resistance to breathing
Carbon dioxide rebreathing
Potential issues Higher non-compliance of guidance
During testing (e.g. failed flow test/disconnected circuit)
During use (e.g. battery discharge and filter problems)
Concerns about use in surgery because of outward airflow and risk of wound infection
Ineffective when moist, wet, or creased
Face seal leak common
Impact on performance Limited visual field
Reduced hearing acuity (fan noise)
Stethoscope use limited
Claustrophobia
Comfortable when worn for extended periods
User may experience headache, giddiness, breathless
Silent, does not interfere with auscultation
Use during resuscitation Battery failure, equipment disconnections, concerns that over-breathing exceeds flow rate Risk of dislodgement and decreased performance