Indian Journal of Critical Care Medicine

Register      Login



Volume / Issue

Online First

Related articles

VOLUME 25 , ISSUE 9 ( September, 2021 ) > List of Articles

Original Article

Fit Factor Change on Quantitative Fit Testing of Duckbill N95 Respirators with the Use of Safety Goggles

Sandy Kyaw, Rimen Lim, Warren C Stewart, Solomon R Thambiraj, David W Collins, Claudia M Whyte

Keywords : Eyeglasses, HCW (Healthcare workers), Infectious diseases, Intensive care, N95 MASK, N95 respirators, Occupational injury, Personal protective equipment, Safety

Citation Information : Kyaw S, Lim R, Stewart WC, Thambiraj SR, Collins DW, Whyte CM. Fit Factor Change on Quantitative Fit Testing of Duckbill N95 Respirators with the Use of Safety Goggles. Indian J Crit Care Med 2021; 25 (9):981-986.

DOI: 10.5005/jp-journals-10071-23972

License: CC BY-NC 4.0

Published Online: 08-09-2021

Copyright Statement:  Copyright © 2021; The Author(s).


N95 respirators and safety goggles are important components of personal protective equipment to reduce the spread of airborne infections, such as COVID-19, among healthcare workers. Poor N95 respirator seal may reduce its protective effect, thereby increasing transmission. Quantitative fit testing is an established way of assessing the N95 respirator fit, which provides a quantitative measure for seal, called the fit factor. Duckbill N95 respirators frequently fail the fit test. We hypothesized that using safety goggles with a wraparound elastic headband will increase their fit-factor by reinforcing the seal between the face and the upper margin of the respirator. We studied the effect of safety goggles with a wraparound elastic headband (3M™ Chemical Splash Resistant Goggles, ID 70006982741) on the fit factor of two types of Duckbill N95 respirators (Halyard FLUIDSHIELD*3, Model 99SA070M, and ProShield® N95 Model TN01-11) in 63 healthy volunteers in a nonrandomized, before-and-after intervention study design. The mean fit factor increased from 69.4 to 169.1 increased from 17/63 (27%) to 46/63 (73%) after the intervention (p <0.0001, OR 3 [95% CI = 4.9–1223]). This is the first study to explore the impact of safety goggles on N95 respirator fit. We conclude that the use of safety goggles with a wraparound elastic headband increases the fit factor of the tested Duckbill N95 respirators.

  1. Haji JY, Subramaniam A, Kumar P, Ramanathan K, Rajamani A. State of personal protective equipment practice in Indian intensive care units amidst COVID-19 pandemic: a nationwide survey. Indian J Crit Care Med 2020;24(9):809–816. DOI: 10.5005/jp-journals-10071-23550.
  2. Chawla G, Abrol N, Kakkar K. Personal protective equipment: a Pandora's box. Indian J Crit Care Med 2020;24(5):371–372. DOI: 10.5005/jp-journals-10071-23443.
  3. Pande RK, Bhalla A, Myatra SN, Yaddanpuddi LN, Gupta S, Sahoo TK, et al. Procedures in COVID-19 patients: part-II. Indian J Crit Care Med 2020;24(Suppl. 5):S272–S279. DOI: 10.5005/jp-journals-10071-23604.
  4. Patel MP, Kute VB, Goswami J, Balwani MR. Hospitals may become “Disease Hotspots” for COVID-19 amid shortage of personal protective equipment. Indian J Crit Care Med 2020;24(11):1145–1146. DOI: 10.5005/jp-journals-10071-23645.
  5. Ramasubban S. COVID collateral: “Don't Forget the Diligent Healthcare Worker”. Indian J Crit Care Med 2020;24(8):613–614. DOI: 10.5005/jp-journals-10071-23542.
  6. Lam SC, Lee JK, Yau SY, Charm CY. Sensitivity and specificity of the user-seal-check in determining the fit of N95 respirators. J Hosp Infect 2011;77(3):252–256. DOI: 10.1016/j.jhin.2010.09.034.
  7. Derrick JL, Chan YF, Gomersall CD, Lui SF. Predictive value of the user seal check in determining half-face respirator fit. J Hosp Infect 2005;59(2):152–155. DOI: 10.1016/j.jhin.2004.09.009.
  8. Regli A, Sommerfield A, von Ungern-Sternberg BS. The role of fit testing N95/FFP2/FFP3 masks: a narrative review. Anaesthesia 2021;76(1):91–100. DOI: 10.1111/anae.15261.
  9. Hon CY, Danyluk Q, Bryce E, Janssen B, Neudorf M, Yassi A, et al. Comparison of qualitative and quantitative fit-testing results for three commonly used respirators in the healthcare sector. J Occup Environ Hyg 2017;14(3):175–179. DOI: 10.1080/15459624.2016.1237030.
  10. Degesys NF, Wang RC, Kwan E, Fahimi J, Noble JA, Raven MC. Correlation between N95 extended use and reuse and fit failure in an emergency department. JAMA 2020;324(1):94–96. DOI: 10.1001/jama.2020.9843.
  11. Roberge RJ, Monaghan WD, Palmiero AJ, Shaffer R, Bergman MS. Infrared imaging for leak detection of N95 filtering facepiece respirators: a pilot study. Am J Ind Med 2011;54(8):628–636. DOI: 10.1002/ajim.20970.
  12. Harber P, Su J, Badilla AD, Rahimian R, Lansey KR. Potential role of infrared imaging for detecting facial seal leaks in filtering facepiece respirator users. J Occup Environ Hyg 2015;12(6):369–375. DOI: 10.1080/15459624.2015.1006636.
  13. Chu DK, Akl EA, Duda S, Solo K, Yaacoub S, Schunemann HJ. Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis. Lancet 2020;395(10242):1973–1987. DOI: 10.1016/S0140-6736(20)31142-9.
  14. Sharma J, Nasa P, Reddy KS, Kuragayala SD, Sahi S, Gopal P, et al. Infection prevention and control for ICU during COVID-19 pandemic: position paper of the Indian Society of Critical Care Medicine. Indian J Crit Care Med 2020;24(Suppl. 5):S280–S289. DOI: 10.5005/jp-journals-10071-23607.
  15. Pande RK, Bhalla A, Myatra SN, Yaddanpuddi LN, Gupta S, Sahoo TK, et al. Procedures in COVID-19 patients: part-I. Indian J Crit Care Med 2020;24(Suppl. 5):S263–S271. DOI: 10.5005/jp-journals-10071-23597.
  16. NIOSH-approved N95 particulate filtering facepiece respirators: National Institute for Occupational Safety and Health; 2020. Available from:
  17. Incorporated T. PORTACOUNT® PRO 8030 AND PORTACOUNT® PRO+ 8038 RESPIRATOR FIT TESTERS Revision P ed. TSI Incorporated/500 Cardigan Road/Shoreview, MN 55126/USA; 2015. p. 87–89.
  18. OSHA. Major requirement of OSHA's respiratory protection standard 29 CFR 1910.134. 2006.
  19. PORTACOUNT RESPIRATOR FIT TESTER 8048. 2021. Available from:
  20. Clayton M, Vaughan N. Fit for purpose? The role of fit testing in respiratory protection. Ann Occup Hyg 2005;49(7):545–548. DOI: 10.1093/annhyg/mei046.
  21. Amemiya T. Tobit models: a survey. J Econom 1984;24(1):3–61. DOI: 10.1016/0304-4076(84)90074-5.
  22. Lee K, Slavcev A, Nicas M. Respiratory protection against Mycobacterium tuberculosis: quantitative fit test outcomes for five type N95 filtering-facepiece respirators. J Occup Environ Hyg 2004;1(1):22–28. DOI: 10.1080/15459620490250026.
  23. Ciotti C, Pellissier G, Rabaud C, Lucet JC, Abiteboul D, Bouvet E. Effectiveness of respirator masks for healthcare workers, in France. Med Mal Infect 2012;42(6):264–269. DOI: 10.1016/j.medmal.2012.05.001.
  24. Wardhan R, Brennan MM, Brown HL, Creech TB. Does a modified adhesive respirator improve the face seal for health care workers who previously failed a fit test?: a pilot study during the coronavirus disease 2019 pandemic. A A Pract 2020;14(8):e01264. DOI: 10.1213/XAA.0000000000001264.
  25. Australian and New Zealand Intensive Care Society (2020) ANZICS COVID-19 guidelines. Melbourne: ANZICS; 2021.
PDF Share
PDF Share

© Jaypee Brothers Medical Publishers (P) LTD.