Health care professionals, as well as business owners and workers in professions requiring close personal contact, must consider several factors when choosing between different types of respiratory protection to reduce exposure to transmissible respiratory pathogens. These factors include current and continued availability, PPE burn rate/cost and respirator efficacy. In addition, user comfort during long periods of PPE use is of vital importance and should be taken into serious consideration when choosing a NIOSH approved particulate-filtering air purifying respirator (APR) such as a tight-fitting N95 filtering facepiece respirator or a loose-fitting powered air purifying respirator (PAPR).
Comfort Equals Compliance
One of the most common concerns about wearing respiratory PPE for lengthy periods of time centers around user comfort. Difficulty breathing, overheating/heat exhaustion, headaches and painful facial irritation and bruising - these are all conditions that health care professionals such as dentists, physical therapists and other workers who need adequate respiratory protection seek to avoid. Respiratory PPE comfort is especially important when considering the extended length of use of such equipment that occurs during the average 8-9 hour work day.
However, respiratory protection effectiveness is seriously impacted if the equipment is so uncomfortable that workers are unable to properly and consistently wear PPE throughout the duration of a standard or extended work shift. According to OSHA, "Employers should take the fit and comfort of PPE into consideration when selecting appropriate items for their workplace. PPE that fits well and is comfortable to wear will encourage employee use of PPE."
Workers using tight-fitting N95 masks for long periods of time frequently sustain facial injuries. These injuries range from red splotches to deep indentations to painful bruises. As reported earlier this year by CBS News, many exhausted doctors and nurses from around the world have recently shared images of their bruised faces on their social media accounts - a direct result of using protective eye goggles and face masks with a tight seal such as the N95 respirator for prolonged periods of time.
Additional discomfort that can result from the N95’s tight seal are headaches. Prolonged use of tight-fitting PPE such as N95 face masks and protective eyewear has been reported to cause an increase in headaches among health care workers. A 2006 article published in the peer-reviewed medical journal Acta Neurologica Scandinavica studied health care workers who mandatorily wore N95 masks during the SARS epidemic in 2003. Researchers found that 37.3% of surveyed health care workers developed headaches specifically attributed to wearing N95 masks during that time. 32.9% of the afflicted workers experienced these headaches at a frequency of more than six times per month - and 7.6% took sick leave as a result of their N95-related headaches.
A recent study of PPE-associated headaches among health care workers during the coronavirus pandemic found that: “The onset of pain was within 1 hour of wearing PPE and spontaneous resolution occurred in most cases within 1 hour from removal of the equipment.” Pain was mainly located in the areas of contact from face mask or eye goggle straps. Headache intensity ranged from mild to severe, with 23.4% of survey respondents reporting migraine-like symptoms including nausea, vomiting and light sensitivity.
Other incidents of PPE-related discomfort that workers report on social media platforms include difficulty breathing when wearing tight-fitting face masks such as the N95 respirator or the elastomeric half facepiece respirator for extended periods of time.
According to the FDA, “People with chronic respiratory, cardiac, or other medical conditions that make breathing difficult should check with their health care provider before using an N95 respirator because the N95 respirator can make it more difficult for the wearer to breathe.”
Tight-fitting respirators such as the N95 face mask were simply not designed to be worn all day. For wearers with medical conditions such as asthma or chronic obstructive pulmonary disease (COPD), it may not be a viable option to wear one for very long at all. A loose-fit battery powered PAPR with hood or helmet eliminates this challenge by providing cool, comfortable and free-flowing breathing air for anywhere from 8-12+ hours (depending on chosen fan speed). Having a backup battery on hand can allow the PAPR wearer to use the system for even longer than that if necessary.
A common concern some workers have regarding extended use of loose-fitting PAPRs with helmets or hoods is heat stress/thermal comfort. Many assume that overheating will occur when using a loose-fitting PAPR for hours at a time. However, in reality, PAPRs deliver cool and comfortable free-flowing filtered breathing air via a battery powered motor-blower. As a result, the PAPR wearer is able to maintain a normal body temperature even after many hours of continuous use.
In fact, according to the trade magazine Infection Control Today, PAPRs may actually be more comfortable in terms of heat stress and body temperature regulation than N95 masks for healthcare workers (HCW):
“Another occupational safety advantage of the PAPR is reduced heart, lung, and heat stress. A N-95 respirator requires the HCW to draw the air in through a resistive filter by virtue of his own heart and lung power. Very quickly the mask begins to become hot and moist causing heat stress; these increased stress factors can reduce focus on the critical tasks of patient care. In comparison, a PAPR employs a battery-operated fan to draw ambient air in through the purifying HEPA filter before it is delivered to the HCW’s breathing zone. Purified air continually flows into the facepiece, cooling the HCW so that he/she can work comfortably for several hours.”
Extended Use of Respiratory Protection - Additional Considerations
Both PAPRs and N95s face masks are respiratory PPE options approved by the Centers for Disease Control and Prevention in its Coronavirus Disease 2019 (COVID-19) guide for health care professionals. However, the filtration efficiency of PAPRs is considered by the CDC to be more protective against airborne particles: “All PAPR APFs exceed the APF of 10 for N95 FFR or elastomeric half facepiece respirators.” (Source: "Considerations for Optimizing the Supply of Powered Air-Purifying Respirators (PAPRs)" at CDC.gov)
Also, unlike loose-fitting PAPRs with helmets or hoods, N95 respirators were not designed for all day wear. Their disposable, single-use design means that the CDC considers usage of a N95 mask for eight hours or more of continuous or intermittent use to be “extended use” - beyond what the manufacturer intended for optimal safety - and therefore only advisable in the face of PPE shortages.
In contrast, a battery powered loose-fitting PAPR is safe and effective to use as long as needed. While the average PAPR battery lasts from 8 to 12+ hours, deployment of a backup battery can extend PAPR usage beyond that period of time if necessary. This is especially useful for health care workers and other professionals working overtime or multiple shifts. In addition, as common tight-fitting respirator maladies - such as facial bruising and headaches - generally do not occur with long term use of loose-fit respirators, user comfort is increased and PPE is more likely to be effectively and safely used throughout the duration of the entire work shift.
In terms of both filtration efficiency and comfort, PAPRs may be a more effective respiratory protection option than N95 masks for extended periods of continuous or intermittent use in health care settings, dental offices, physical therapy offices and other work environments.