Performance of facepiece respirators and surgical masks against surgical smoke: simulated workplace protection factor study
Open accessAbstract
OBJECTIVE: Surgical smoke generated during electrocautery contains toxins which may cause adverse health effects to operating room (OR) personnel. The objective of this study was to investigate the performance of surgical masks (SMs), which are routinely used in ORs, more efficient N95 surgical mask respirator (SMRs) and N100 filtering facepiece respirator (FFRs), against surgical smoke. METHODS: Ten subjects were recruited to perform surgical dissections on animal tissue in a simulated OR chamber, using a standard electrocautery device, generating surgical smoke. Six respiratory protective devices (RPDs) were tested: two SMs, two SMRs, and two N100 FFRs [including a newly developed faceseal (FS) prototype]. Fit testing was conducted before the experiment. Each subject was then exposed to the surgical smoke while wearing an RPD under the tests. Concentrations inside (C in) and outside (C out) of the RPD were measured by a particle size spectrometer. The simulated workplace protection factor (SWPF) was determined by the ratio of C out and C in for each RPD-wearing subject. RESULTS: For the SMs, the geometric means of SWPFtotal (based on the total aerosol concentration) were 1.49 and 1.76, indicating minimal protection. The SWPFtotal values of the SMRs and N100 FFRs were significantly higher than those of the SMs: for the two SMRs, the SWPFtotal were 208 and 263; for the two N100s, the SWPFtotal values were 1,089 and 2,199. No significant difference was observed between either the two SMs or the two SMRs. The SWPFtotal for the novel FS prototype N100 FFR was significantly higher than the conventional N100 FFR. The correlation between SWPFtotal and fit factor (FF) determined for two N95 SMRs was not significant. CONCLUSIONS: SMs do not provide measurable protection against surgical smoke. SMRs offer considerably improved protection versus SMs, while the N100 FFRs showed significant improvement over the SMRs. The FS prototype offered a higher level of protection than the standard N100 FFR, due to a tighter seal. While we acknowledge that conventional N100 FFRs (equipped with exhalation valves) are not practical for human OR use, the results obtained with the FS prototype demonstrate the potential of the new FS technology for implementation on various types of respirators.
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N95 FFRs are employed as personal protective equipment (PPE) and they provide a high level of protection for filtering facepiece masks that cover only the nose and mouth.
“N95 FFR are employed as personal protective equipment (PPE) and they provide a high level of protection for filtering facepiece masks that cover only the nose and mouth (as opposed to full and half-face respirators constructed from elastomeric materials) [3, 58–74].”
From The protective performance of reusable cloth face masks, disposable procedure masks, KN95 masks and N95 respirators: Filtration and total inward leakage (2021) · cites this paper as [66]
The Abstract describes fit-tested surgical N95 FFRs as recommended PPE, while noting that their operating-room use was primarily limited to HPV-related procedures. The Conclusions report substantial protection against surgical smoke for the two tested N95 respirators. Our copy does not make the claimed nose-and-mouth coverage distinction or compare their construction with elastomeric full- and half-face respirators. (LLM, conf=0.83)
Experimental — accuracy not yet measuredThe Quality Factor (QF) is commonly used to compare the performance of materials used to filter particulates under similar experimental conditions.
“The Quality Factor (QF) is commonly used to compare the performance of materials used to filter particulates under similar experimental conditions [62–81];”
From The protective performance of reusable cloth face masks, disposable procedure masks, KN95 masks and N95 respirators: Filtration and total inward leakage (2021) · cites this paper as [66]
The Experimental setup section defines simulated workplace protection factor (SWPF), and the results compare respirators and masks using that measure. Searches for “quality factor,” “QF,” and comparisons of filter materials found no passage addressing the claimed use of QF. Page numbers were not available in our copy. (LLM, conf=0.75)
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Cites
Isolation of a Novel Coronavirus from a Man with Pneumonia in Saudi Arabia
Zaki, A. M., van Boheemen, S., Bestebroer, T. M., Osterhaus, A. D. M. E., & Fouchier, R. A. M. (2012) · New England Journal of Medicine · doi:10.1056/nejmoa1211721 · Cited by 5,677 · see citing works
Characterization of a Novel Coronavirus Associated with Severe Acute Respiratory Syndrome
Rota, P. A., Oberste, M. S., Monroe, S. S., Nix, W. A., Campagnoli, R. P., Icenogle, J. P., Peñaranda, S., Bankamp, B., Maher, K., Chen, M., et al. (2003) · Science · doi:10.1126/science.1085952 · Cited by 2,477 · see citing works
Kulkarni, P., Baron, P. A., & Willeke, K. (2011) · Wiley eBooks · doi:10.1002/9781118001684 · Cited by 1,363 · see citing works
Papillomavirus genome structure, expression, and post-transcriptional regulation
Zheng, Z. (2006) · Frontiers in bioscience · doi:10.2741/1971 · Cited by 496 · see citing works
Bałazy, A., Toivola, M., Adhikari, A., Sivasubramani, S. K., Reponen, T., & Grinshpun, S. A. (2006) · American Journal of Infection Control · doi:10.1016/j.ajic.2005.08.018 · Cited by 376 · see citing works
Self-citationSurgical smoke and infection control
Alp, E., Bijl, D., Bleichrodt, R. P., Hansson, B. M. E., & Voss, A. (2005) · Journal of Hospital Infection · doi:10.1016/j.jhin.2005.01.014 · Cited by 348 · see citing works
Surgical smoke: a review of the literature
Barrett, W. L., & Garber, S. M. (2003) · Surgical Endoscopy · doi:10.1007/s00464-002-8584-5 · Cited by 316 · see citing works
Bałazy, A., Toivola, M., Reponen, T. A., Podgórski, A., Zimmer, A. T., & Grinshpun, S. A. (2005) · The Annals of Occupational Hygiene · doi:10.1093/annhyg/mei058 · Cited by 237 · see citing works
Self-citationHensman, C., Baty, D. U., Willis, R. G., & Cuschieri, A. (1998) · Surgical Endoscopy · doi:10.1007/s004649900771 · Cited by 161 · see citing works
Aerosol penetration and leakae characteristics of masks used in the health care industry
Weber, A. M., Willeke, K., Marchloni, R., Myojo, T., McKay, R. T., Donnelly, J., & Liebhaber, F. B. (1993) · American Journal of Infection Control · doi:10.1016/0196-6553(93)90027-2 · Cited by 156 · see citing works
Surgical smoke and ultrafine particles
Brüske‐Hohlfeld, I., Preißler, G., Jauch, K., Pitz, M., Nowak, D., Peters, A., & Wichmann, H. ‐. (2008) · Journal of Occupational Medicine and Toxicology · doi:10.1186/1745-6673-3-31 · Cited by 148 · see citing works
Animal Viruses: Molecular Biology
Mahy, B. W. J. (2008) · Emerging infectious diseases · doi:10.3201/eid1405.080077 · Cited by 147 · see citing works
Effectiveness of surgical masks against influenza bioaerosols
Makison Booth, C., Clayton, M., Crook, B., & Gawn, J. M. (2013) · Journal of Hospital Infection · doi:10.1016/j.jhin.2013.02.007 · Cited by 132 · see citing works
Weld, K. J., Dryer, S., Ames, C. D., Cho, K., Hogan, C. J., Lee, M., Biswas, P., & Landman, J. (2007) · Journal of Endourology · doi:10.1089/end.2006.9994 · Cited by 123 · see citing works
Chemical composition of smoke produced by high-frequency electrosurgery
Sahaf, O. S. A., Vega-Carrascal, I., Cunningham, F. O., McGrath, J. P., & Bloomfield, F. J. (2007) · Irish Journal of Medical Science (1971 -) · doi:10.1007/s11845-007-0068-0 · Cited by 100 · see citing works
Proper Use of Surgical N95 Respirators and Surgical Masks in the OR
Benson, S. M., Novak, D. A., & Ogg, M. J. (2013) · AORN Journal · doi:10.1016/j.aorn.2013.01.015 · Cited by 66 · see citing works
Zhuang, Z., Coffey, C. C., Jensen, P. A., Campbell, D. L., Lawrence, R. B., & Myers, W. R. (2003) · AIHA Journal · doi:10.1080/15428110308984867 · Cited by 53 · see citing works
Reponen, T. A., Lee, S.-A., Grinshpun, S. A., Johnson, E., & Mckay, R. (2010) · The Annals of Occupational Hygiene · doi:10.1093/annhyg/meq085 · Cited by 48 · see citing works
Self-citationPeritonectomy with high voltage electrocautery generates higher levels of ultrafine smoke particles
Andréasson, S., Anundi, H., Sahlberg, B., Ericsson, C.-G., Wålinder, R., Enlund, G., Påhlman, L., & Mahteme, H. (2008) · European Journal of Surgical Oncology · doi:10.1016/j.ejso.2008.09.002 · Cited by 39 · see citing works
Krones, C. J., Conze, J., Hoelzl, F., Stumpf, M., Klinge, U., Möller, M., Dott, W., Schumpelick, V., & Hollender, J. (2007) · European surgery. Supplement/European surgery · doi:10.1007/s10353-006-0305-1 · Cited by 37 · see citing works
Sampling and Analysis Using Filters
Raynor, P. C., Leith, D. E., Lee, K. W., & Mukund, R. (2011) · Wiley eBooks · doi:10.1002/9781118001684.ch7 · Cited by 23 · see citing works
The Hazards of Surgical Smoke Not to be Sniffed At!
Biggins, J., & Renfree, S. (2002) · Journal of Perioperative Practice · doi:10.1177/175045890201200401 · Cited by 18 · see citing works
Zhuang, Z., Coffey, C. C., Jensen, P. A., et al. (2003) · AIHA Journal · doi:10.1202/475.1 · Cited by 17 · see citing works
Respiratory protection--OSHA. Final rule; request for comment on paperwork requirements.
(1998) · PubMed · Cited by 14 · see citing works
Rozzi, T. R., Snyder, J. L., & Novak, D. A. (2012) · Journal of Occupational and Environmental Hygiene · doi:10.1080/15459624.2012.718943 · Cited by 12 · see citing works
Koehler, R. H., He, K., & Grinshpun, S. A. (2015) · doi:10.13140/rg.2.1.1964.1844 · Cited by 9 · see citing works
Self-citation
Flagged first, then by citations
Research works printed but not linked: 5
- respirators challenged with nanoparticles. Ann Occup Hyg; 50: 259-69.
- Dixon SW, Nelson TJ. (1984) Workplace protection factors for negative pressure half-mask facepiece respirator. J Int Soc Resp Prot; 2: 347-61.
- Hohlfeld B, Preissler G, Jauch KW et al. (2008) Surgical smoke and ultrafine particles. J Occup Med Tox; 3: 31.
- OSHA. (1998) Respiratory protection; final rule. Federal Register; 63: 1152-300.
- Pollock SV. (2008) Electrosurgery. In Bolognia JL, Jorizzo JL, Rapini RP, editors. dermatology. 2nd ed. Philadelphia, PA: Mosby Elsevier.
Cited by
Sorted by citations
Particle Sizes of Infectious Aerosols: Implications for Infection Control
Fennelly, K. P. (2020) · The Lancet Respiratory Medicine · doi:10.1016/s2213-2600(20)30323-4 · Cited by 621 · see citing works
Effectiveness of face masks used to protect Beijing residents against particulate air pollution
Cherrie, J. W., Apsley, A., Cowie, H. A., Steinle, S., Mueller, W., Lin, C., Horwell, C. J., Sleeuwenhoek, A., & Loh, M. M. (2018) · Occupational and Environmental Medicine · doi:10.1136/oemed-2017-104765 · Cited by 174 · see citing works
Liu, Y., Song, Y., Hu, X., Yan, L., & Zhu, X. (2019) · Journal of Cancer · doi:10.7150/jca.31464 · Cited by 159 · see citing works
The Dangers of Electrosurgical Smoke to Operating Room Personnel: A Review
Bree, K., Barnhill, S. W., & Rundell, W. K. (2017) · Workplace Health & Safety · doi:10.1177/2165079917691063 · Cited by 87 · see citing works
Duncan, S., Bodurtha, P., & Naqvi, S. (2021) · PLOS ONE · doi:10.1371/journal.pone.0258191 · Cited by 75 · see citing works
Surgical smoke control with local exhaust ventilation: Experimental study
Lee, T., Soo, J., LeBouf, R. F., Burns, D. A., Schwegler‐Berry, D., Kashon, M. L., Bowers, J., & Harper, M. (2017) · Journal of Occupational and Environmental Hygiene · doi:10.1080/15459624.2017.1422082 · Cited by 69 · see citing works
Choi, S. H., Choi, D. H., Kang, D. H., Ha, Y., Lee, J. N., Kim, B. S., Kim, H. T., Yoo, E. S., Kwon, T. G., Chung, S. K., et al. (2018) · Surgical Endoscopy · doi:10.1007/s00464-018-6222-0 · Cited by 37 · see citing works
Surgical smoke simulation study: Physical characterization and respiratory protection
Elmashae, Y., Koehler, R. H., Yermakov, M. V., Reponen, T. A., & Grinshpun, S. A. (2017) · Aerosol Science and Technology · doi:10.1080/02786826.2017.1373180 · Cited by 26 · see citing works
Self-citationExploring respiratory protection practices for prominent hazards in healthcare settings
Wizner, K., Nasarwanji, M. F., Fisher, E. M., Steege, A. L., & Boiano, J. M. (2018) · Journal of Occupational and Environmental Hygiene · doi:10.1080/15459624.2018.1473581 · Cited by 26 · see citing works
Surgical Team Exposure to Cautery Smoke and Its Mitigation during Tonsillectomy
O’Brien, D. C., Lee, E. G., Soo, J., Friend, S. A., Callaham, S., & Carr, M. M. (2020) · Otolaryngology · doi:10.1177/0194599820917394 · Cited by 25 · see citing works
Surgical smoke and its components, effects, and mitigation: a contemporary review
Benaim, E. H., & Jaspers, I. (2024) · Toxicological Sciences · doi:10.1093/toxsci/kfae005 · Cited by 24 · see citing works
Casey, V. J., Martin, C., Curtin, P., Buckley, K., & McNamara, L. M. (2020) · Annals of Biomedical Engineering · doi:10.1007/s10439-020-02587-w · Cited by 24 · see citing works
Tan, W., Zhu, H., Zhang, N., Dong, D., Wang, S., Ren, F., Xiang, J., Wu, R., & Lv, Y. (2019) · Environmental Toxicology and Pharmacology · doi:10.1016/j.etap.2019.103248 · Cited by 24 · see citing works
Casey, V. J., & McNamara, L. M. (2023) · Annals of Surgery · doi:10.1097/sla.0000000000005816 · Cited by 17 · see citing works
Benson, S. M., Maskrey, J. R., Nembhard, M. D., Unice, K. M., Shirley, M. A., & Panko, J. M. (2019) · Annals of Work Exposures and Health · doi:10.1093/annweh/wxz070 · Cited by 17 · see citing works
Chan, Y., Banglawala, S. M., Chin, C. J., Côté, D. W. J., Dalgorf, D. M., de Almeida, J. R., Desrosiers, M. Y., Gall, R. M., Gevorgyan, A. M., Hassan, A. H., et al. (2020) · Journal of Otolaryngology - Head and Neck Surgery · doi:10.1186/s40463-020-00476-9 · Cited by 13 · see citing works
Elmashae, R. B. Y., Grinshpun, S. A., Reponen, T., Yermakov, M., & Riddle, R. (2017) · Journal of Occupational and Environmental Hygiene · doi:10.1080/15459624.2017.1319571 · Cited by 12 · see citing works
Self-citation3D Printed Mask Frames Improve the Inward Protection Efficiency of a Cloth Mask
Tong, Y., Pan, J., Küçükdeğer, E., Johnson, A. L., Marr, L. C., & Johnson, B. N. (2021) · ACS ES&T Engineering · doi:10.1021/acsestengg.1c00028 · Cited by 12 · see citing works
Dellweg, D., Haidl, P., Kerl, J., Maurer, L., & Köhler, D. (2021) · Journal of Occupational and Environmental Hygiene · doi:10.1080/15459624.2020.1862417 · Cited by 7 · see citing works
Engineering controls for surgical smoke in laser medical handpieces
Jones, L. C. R., Parry, M., Britton, J., & Tyrer, J. R. (2021) · Journal of Laser Applications · doi:10.2351/7.0000360 · Cited by 6 · see citing works
Heroor, A., Asaf, B. B., Deo, S., Lau, E. H. L., Mok, C. W., DiPasco, P. J., Jain, P. K., & Anand, U. (2022) · Frontiers in Public Health · doi:10.3389/fpubh.2022.899171 · Cited by 5 · see citing works
Clearing the Smoke: The Evidence behind Risk of Electrocautery Smoke and Mitigation Strategies
Tyle, M. R., Olafson, A., Hiro, M. E., & Payne, W. G. (2024) · Plastic & Reconstructive Surgery Global Open · doi:10.1097/gox.0000000000006039 · Cited by 4 · see citing works
Rao, R. S., Sasiharan, G. M., & Ganapathy, S. (2023) · Indian Journal of Occupational and Environmental Medicine · doi:10.4103/ijoem.ijoem_200_22 · Cited by 4 · see citing works
Meretsky, C. R., Mahmoodi, A., Knecht, E. M., Popovich, J., & Schiuma, A. T. (2024) · Cureus · doi:10.7759/cureus.58106 · Cited by 6 · see citing works
Surgical smoke: a matter of hygiene, toxicology, and occupational health
Kahramansoy, N. (2024) · PubMed Central · doi:10.3205/dgkh000469 · Cited by 2 · see citing works
Moore, H., & Palokas, M. J. (2024) · International Journal of Evidence-Based Healthcare · doi:10.1097/xeb.0000000000000402 · Cited by 2 · see citing works
Okubo, C. V. C., Ribeiro, R. P., Martins, J. T., & Marziale, M. H. P. (2017) · Cogitare Enfermagem · doi:10.5380/ce.v22i3.50115 · Cited by 2 · see citing works
Evaluation of Surgeon’s Exposure to Formaldehyde, PM 2.5, and Volatile Organic Compounds
Jadhav, R., & Achutan, C. (2020) · Journal of Public Health Issues and Practices · doi:10.33790/jphip1100172 · Cited by 2 · see citing works
Surgical smoke and occupational health
Canicoba, A. R. B. (2022) · Annals of Translational Medicine · doi:10.21037/atm-22-5631 · Cited by 2 · see citing works
Ten questions concerning particle exposure in open electrosurgery and its control strategies
Wu, X., Ding, Y., Zhang, Y., Ding, Z., & Qian, H. (2024) · International Journal of Ventilation · doi:10.1080/14733315.2024.2412454 · Cited by 1 · see citing works
Strategies to Improve Compliance With Smoke Safety
Dennis, E., & Ball, K. (2026) · AORN Journal · doi:10.1002/aorn.70159 · Cited by 1 · see citing works
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Malik, S., Khairi, F., & Wijerathne, S. I. (2022) · Springer eBooks · doi:10.1007/978-981-19-3755-2_11 · Cited by 1 · see citing works
Knowledge mapping of surgical smoke from 2003 to 2022: a bibliometric analysis
Li, C., Geng, M., Li, S., Li, X., Li, H., Yuan, H., & Liu, F. (2024) · Surgical Endoscopy · doi:10.1007/s00464-023-10641-6 · Cited by 1 · see citing works
Netto, C. M., Leachi, H. F. L., Stanganelli, N. C., da Rocha, A. F., & Ribeiro, R. P. (2021) · Ciência Cuidado e Saúde · doi:10.4025/ciencuidsaude.v20i0.55482 · Cited by 1 · see citing works
N95 Respirators for Dermatologic Surgery and Laser Procedures During COVID-19 and Beyond
Kashlan, R., Lyons, A. B., Hivnor, C. M., & Ozog, D. (2020) · Dermatologic Surgery · doi:10.1097/dss.0000000000002749
Treviso, P., Peradotto, B. C., Campiol, J. V., Knihs, N. D. S., Pereira, M. C. D. O., & Moriya, G. A. D. A. (2022) · Revista Sobecc · doi:10.5327/z1414-4425202100040005
HeLP: Desenvolvimento de máscara de proteção ocupacional contra a fumaça cirúrgica
Leachi, H. F. L., & Ribeiro, R. P. (2023) · Revista Brasileira de Enfermagem · doi:10.1590/0034-7167-2022-0647pt
HeLP: Development of occupational protection mask against surgical smoke
Leachi, H. F. L., & Ribeiro, R. P. (2023) · Revista Brasileira de Enfermagem · doi:10.1590/0034-7167-2022-0647
Walradt, T. J., Szvarca, D., Hart, J. E., Adamkiewicz, G., Nie, Q., Wissoker, M., Desai, K., Wang, Y., Aihara, H., & Thompson, C. C. (2025) · The American Journal of Gastroenterology · doi:10.14309/ajg.0000000000003388
Evaluation of a smoke extraction system for veterinarian exposures to surgical smoke—A pilot study
Anderson, K. R., & Arai, S. (2025) · Journal of Occupational and Environmental Hygiene · doi:10.1080/15459624.2025.2496493
Vers un bloc opératoire sans fumées : revue de littérature
Brillat, E. (2025) · Interbloc · doi:10.1016/j.bloc.2025.06.007
Bieniek, A. A., Leachi, H. F. L., da Rocha, A. F., da Silva, R. M., & Ribeiro, R. P. (2025) · Cogitare Enfermagem · doi:10.1590/ce.v30i0.97664en
Bieniek, A. A., Leachi, H. F. L., da Rocha, A. F., da Silva, R. M., & Ribeiro, R. P. (2025) · Cogitare Enfermagem · doi:10.1590/ce.v30i0.97664pt
Bieniek, A. A., Leachi, H. F. L., da Rocha, A. F., da Silva, R. M., & Ribeiro, R. P. (2025) · Cogitare Enfermagem · doi:10.1590/ce.v30i0.97664es
Hey, S. Y., Saibene, A. M., Amin, M. R., Anderson, J. A., Arens, C., Best, S. R., Campos, G., Derkay, C. S., Desuter, G., Dikkers, F. G., et al. (2026) · European Archives of Oto-Rhino-Laryngology · doi:10.1007/s00405-026-10451-1
- Authors
- Gao, S., Koehler, R. H., Yermakov, M., & Grinshpun, S. A.
- Affiliations
- University of Cincinnati (US)
- Martha's Vineyard Hospital (US)
- Corresponding author
- Grinshpun, Sergey A.
- Venue
- Annals of Occupational Hygiene
- Publisher
- Oxford University Press (OUP)
- Published
- 2016-02-28
- Volume
- 60
- Issue
- 5
- Pages
- 608-618
- ISSN
- 0003-4878 (ISSN-L)
- 1475-3162
- PMC
- PMC7109898
- OpenAlex
- W2291506400
- Cited by
- 46
- References
- 25
- Citations by year
- 2026: 2 · 2025: 6 · 2024: 8 · 2023: 4 · 2022: 4 · 2021: 5 · 2020: 6 · 2019: 3 · 2018: 3 · 2017: 5
- FWCI
- 3.28
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Locations
- The Annals of Occupational Hygiene (publishedVersion)
- Europe PMC (PubMed Central) (publishedVersion)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- HighWire Press Open Archive (submittedVersion)
- Topics
- Health Sciences › Medicine › Pulmonary and Respiratory Medicine › Infection Control and Ventilation
- Health Sciences › Health Professions › Occupational Therapy › Occupational Health and Safety in Workplaces
- Health Sciences › Health Professions › Occupational Therapy › Occupational Health and Performance
- Keywords
- surgical smoke, N95 respirators, surgical masks, surgical workforce, electrocautery, workplace protection factor, respiratory protection, aerosol filtration, fit testing, exhalation valve, fit factor, particle size distribution
- MeSH terms
- Air Pollutants, Occupational, Female, Humans, Male, Masks, Materials Testing, Operating Rooms, Particle Size, Respiratory Protective Devices, Smoke, Occupational Exposure, Workplace, Inhalation Exposure
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