Three (3) guidelines for protecting the skin under N95 respirators/FPE,1–3 were reviewed. All 3 recommended applying a liquid skin sealant prior to donning FPE as both a preventive measure for, and treatment of, skin breakdown.1–3 Applying thin, prophylactic dressings under FPE was described as a possible mitigation for skin injury but was proposed with caution because of the lack of evidence-based information to ensure uncompromised respirator fit and seal.1–3
The CWON NPs contacted SBUH’s Environmental Health and Safety (EHS) Department for assistance in determining how best to test the seal of the N95 respirators while using facial dressings. There are 2 methods of respirator fit testing used in health care institutions, qualitative and quantitative.4 Qualitative fit testing is a pass/fail method using one’s sense of taste, smell, or reaction to an irritant to detect leakage into the respirator but does not measure the amount of leakage. Quantitative fit testing uses a machine and probe attached to the respirator to measure the amount of leakage into the respirator and does not rely on an individual’s senses. Both methods are accepted by the Occupational Safety and Health Administration.4 SBUH used the quantitative method when fit testing N95 respirators.
A healthcare specialist from the EHS Department performed quantitative fit testing using the N95 respirators (Health Care Particulate Respirator and Surgical Mask [product numbers 1860 regular and 1860S small]); 3M, St. Paul, MN) on 2 healthy members of the health care staff who had different facial structures. The fit testing process used the PortaCount Pro+ Respirator Fit Tester 8038 (TSI, Shoreview, MN), which is an ambient particle counting device that provides quantitative assessments of face seal leakage5 (Figure 1). Use of this device is an accepted fit test method by the American National Standards Institute6; Canadian Standards Association7; Health and Safety Executive8; and Occupational Safety and Health Administration4 for all tight-fitting respirators. The healthcare safety specialist fitted the N95 respirator with a probe, which was connected to the fit testing unit via a tube. The probe was installed using a sharp tool that pierces the N95 and “loads” the probe within the “breathing zone” of the respirator, which is usually in the center, between the person’s nose and mouth (Figure 2).5
The device fit-tests the person wearing the respirator while he or she performs the following exercises: breathing normally, breathing deeply, moving the head side to side, moving the head up and down, talking, grimacing, bending at the waist, and repeating normal breathing. The device calculates a fit factor grade for each of these exercises and an overall fit factor grade for all the exercises combined.5
The fit factor is the ratio of the number of particles measured inside and outside the respirator. It is the numerical result of the quantitative fit test performed on a respirator’s facepiece and indicates the effectiveness of the seal against the individual’s face. It is expressed as a ratio that identifies how many times “cleaner” the air inside the respirator’s facepiece is compared with the air outside the facepiece. The acceptable fit factor for an N95 respirator is 100 or higher.5
Testing was performed using a liquid skin barrier (Cavilon Advanced Skin Protectant; 3M) as the control product, a transparent film dressing (Tegaderm; 3M), a light silicone-based adhesive dressing (Mepilex Lite; Mölnlycke Health Care, Gothenburg, Sweden), and an extra-thin hydrocolloid dressing (DuoDerm Extra Thin; ConvaTec, Bridgewater Township, NJ).
The CWON NPs sent out an emergency, high-priority email questionnaire to obtain feedback about the most common location of skin issues from wearing an N95 mask; the most reported locations were the bridge of the nose and cheekbones. Therefore, the dressings used for testing were placed on the face in those areas (Figure 3).
The dressings were cut into rectangles and applied as follows: a 2.5 cm × 6 cm piece was placed on the bridge of the nose, while a 2.5 cm × 2.5 cm piece was placed on each cheekbone. Dressings were placed to sit under the edges of the N95 respirator, and size and placement were consistent with each dressing type on both test subjects with no dressing overlap. Dressings were gently removed between testing without adhesive removers. The testing procedure took approximately 20 to 30 minutes per dressing for each individual, allowing approximately 5-minute intervals between each test. Each participant used the same respirator for all dressings. Participant 1 used the 1860S (small) respirator, and participant number 2 used the 1860 (regular) respirator. Both participants agreed to participate, and participant 1 gave her permission for her photographs to be used in this publication.