|Year : 2020 | Volume
| Issue : 5 | Page : 58-61
Saving the savior in COVID19 pandemic: Face masks
Manas Ghosh1, Ambarish Bhattacharyya2, Kaushik Ghosh1, Kabita Bhattacharya3, Arup Halder4
1 Department of Medicine, Murshidabad Medical College, Berhampore, West Bengal, India
2 Department of Medicine, Nightingale Hospital, Kolkata, West Bengal, India
3 Department of Laboratories, Glocal Healthcare, Kolkata, West Bengal, India
4 Department of Chest Medicine, Woodlands Hospital, Kolkata, West Bengal, India
|Date of Submission||30-Apr-2020|
|Date of Decision||30-Apr-2020|
|Date of Acceptance||02-May-2020|
|Date of Web Publication||04-Jun-2020|
Dr. Kaushik Ghosh
Department of Medicine, Murshidabad Medical College, Berhampore - 742 101, West Bengal
Source of Support: None, Conflict of Interest: None
Using masks for self-protection has a long history. There are records of the use of masks ranging as far back as the Roman era to Medieval Europe, where masks were used as protective devices. During many festivities, masks were used as a fashion statement. Gas masks were commonly used during the world wars. As pollution started growing, people started using pollution masks. 2020 might be the only era when the entire human population has been forced to wear masks to protect themselves and to protect others. As expected, the healthcare workers, who are leading the fight against the COVID19, are the ones who are most at the need of these devices. Unfortunately, there is a shortage of personal protection equipment all over the world. Hence, we must understand their properties and strengths, and hence that we can achieve maximum benefits from the limited resources.
Keywords: COVID19, mask, pandemic, personal protective equipment, reuse, sterilization
|How to cite this article:|
Ghosh M, Bhattacharyya A, Ghosh K, Bhattacharya K, Halder A. Saving the savior in COVID19 pandemic: Face masks. Int J Health Allied Sci 2020;9, Suppl S1:58-61
|How to cite this URL:|
Ghosh M, Bhattacharyya A, Ghosh K, Bhattacharya K, Halder A. Saving the savior in COVID19 pandemic: Face masks. Int J Health Allied Sci [serial online] 2020 [cited 2020 Jul 2];9, Suppl S1:58-61. Available from: http://www.ijhas.in/text.asp?2020/9/5/58/285966
Roman miners were known to have used animal bladders as safety masks. In the 16th century, Leonardo da Vinci seems to have advised sailors to use wet cloth around their faces to combat toxic weapons. Even visors used as armor by the knights seem to be face masks protecting them in battle! The modern-day mask was probably invented by the French scientist Jean-François Pilâtre de Rozier in the 18th century. Today, the face mask is arguably the most important armor in our battle against COVID19.
SARS-CoV-2 is transmitted through droplets that get generated when people cough, sneeze, or exhale, and also by direct contact through touching contaminated surfaces or objects and then touching their own mouth, nose, or possibly their eyes.,,,,, When the droplet particles are >5–10 μm in diameter, they are called respiratory droplets, and a droplet of <5 μm in diameter called droplet nuclei.
Few years back, the personal protection equipment (PPE) recommendations for health-care workers (HCWs) issued by the Indian Council of Medical Research (ICMR), were to use gown + gloves + surgical grade fluid-resistant mask to protect from larger particles and droplets (such as influenza, mumps, and N. Meningitis) but gown + gloves + N95 mask during care of the patients suffering from airborne diseases (such as measles, chickenpox, and tuberculosis, etc). Summary from ICMR elaborated in [Table 1].
|Table 1: Summary of precautions to prevent the spreading and transmission of infections|
Click here to view
The same principles and guidelines should be extrapolated for the management of Covid19 patients too.
| Masks Available Are Mainly of Three Types|| |
This is useless for HCWs. Cloth masks are not even recommended during surgical procedures as it may increase the chances of surgical site infection. Their use is only recommended for the general population. These can limit the wearer from exhaling massive amounts of virus through droplet generation. In this context, a finer weave, more layers, and a tighter fit give better effectiveness.
Triple layer mask (3 ply) or surgical grade mask
A triple layer surgical mask is fluid-resistant disposable mask. It is better than a cloth mask in preventing influenza and respiratory tract illness. Surgical masks reduce 2.8 fold virus in aerosol and 25 fold reduction of viruses droplets. Overall surgical mask produces 3.4-fold reduction in viral shedding. When the surgical mask is used during cough, it will reduce both droplets and aerosols spreading from infected persons to others by acting as a barrier and reduces the minimum infective dose (MID). However, it does not protect the wearer from acquiring infection as droplets and aerosols can both enter freely through it. However, if both the patients as well as the HCWs are wearing them, then the chances of spreading infection become less (although the threat remains).
N-95 respirator mask
Different countries have their own standardization methods for certifying respirator masks:
- N95 (United States National Institute for Occupational Safety and Health [NIOSH]-42CFR84)
- Filtering facepiece particles 2 (FFP2) (Europe EN 149-2001)
- KN95 (China GB2626-2006)
- P2 (Australia/New Zealand AS/NZA 1716:2012)
- Korea 1st class (Korea KMOEL-2017-64)
- DS (Japan JMHLW-Notification 214, 2018).
The American and European standards are the most commonly used standardizations. The US NIOSH classifies mask into nine categories (N95, N99, N100, P95, P99, P100, R95, R99, and R100). Numerical designations 95, 99, and 100 show the filter's minimum filtration efficiency with 95%, 99%, and 99.97%, respectively. The alphabets stand for N (not resistant to oil); R (somewhat resistant to oil), andP(strongly resistant to oil) means that this respirator can be used for the protection against nonoily and oily aerosols.
FFP stands for FFP, which is the European Union standard. They are three categories: FFP1 gives 80% aerosol filtration, whereas FFP2 and FFP3 not < 94% and not <99% aerosol filtration.,
Comparison between the certifications is elaborated in [Table 2].
|Table 2: Comparison of FFP2, KN95, and N95 and other filtering facepiece respirator classes|
Click here to view
N95 mask filters 95% particles of 0.3 μ or more and N 99 filters 99% of such particles. However, COVID19 is a single stand + SS-RNA virus having a diameter of particles range from 60 to 140 nm (0.06–0.14 μm) with distinctive spikes about 8–12 nm in length and it is transmitted through respiratory droplets. Hence, will it be possible to filter COVID19 even by N95 masks? It still remains to be seen! however, they are the best that we have at this point of time to decrease the MID. Furthermore, although the above certifications seem to be almost similar, and according to the WHO N95 and FFP2 are equally effective. researchers investigating the protection by different respirators against particles between 0.093 and 1.61 μm found minimum protection for particle sizes between 0.263 and 0.384 μm for all FFP masks (including FFP3). Hence, FFP masks (including FFP3) are probably inferior to N95.
Currently, ICMR recommends N95 masks for all HCWs as a part of PPE tackling COVID19 patients. Unfortunately, HCWs are facing PPE shortages all over the world, and we are forced to find substitutes and ways to reuse even single-use (disposable) items.
| Reusing Surgical Masks|| |
Although no manufacturer advises reuse of disposable items, special times call for special actions. As such, extended use and reuse of even disposable surgical masks have been undertaken all over the world. Washing and drying, to keeping it folded in half (so that the outer and inner surfaces do not come in contact) for a few days, to autoclaving, are all being tried. Micheal Chang of McGovern Medical School Houston says one technique could be “to leave it stored in a container in the contaminated area for 72 h. You don't want it to be air-tight as air circulation helps with drying and may help inactivate the virus.” Another technique is to wear a face shield in addition to the mask. This would work as an adjunct to the mask, preventing the masks from getting exposed to heavy viral loads.
| Reusing N95 Masks|| |
Surgical masks, N95 masks and respirators can be reused. Some of the most commonly advocated methods of sterilization are detailed in [Table 3].
|Table 3: Summary of crisis standards of care decontamination recommendations|
Click here to view
However, if there is any possibility that the surface of the masks has got soiled or the possibility that the respirators might have been compromised, then it is better not to reuse these masks. With the entire world fighting this menace, let us all HCWs, make the best of what is available, and stay safe.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Women in the US Military – History of Gas Masks; 11 September, 2001. Available from: http://Chnm.gmu.edu
. [Last retrieved on 2010 Apr 18].
Liu J, Liao X, Qian S, Yuan J, Wang F, Liu Y, et al.
Community transmission of severe acute respiratory syndrome coronavirus 2, Shenzhen, China, 2020. Emerg Infect Dis 2020;26:1320-1323. doi:10.3201/eid2606.200239.
Chan JF, Yuan S, Kok KH, To KK, Chu H, Yang J, et al
. A familial cluster of pneumonia associated with the 2019 novel coronavirus indicating person-to-person transmission: A study of a family cluster. Lancet 2020;395:514-23.
Li Q, Guan X, Wu P, Wang X, Zhou L, Tong Y, et al
. Early transmission dynamics in Wuhan, China, of novel coronavirus-infected pneumonia. N
Engl J Med 2020;382:1199-207.
Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y, et al
. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet 2020;395:497-506.
RM, Midgley CM, Dratch A, Fenstersheib M, Haupt T, Holshue M, et al.
Active monitoring of persons exposed to patients with confirmed COVID 19 — United States, January–February 2020. MMWR Morb Mortal Wkly Rep 2020;69:245-246. doi:10.15585/mmwr.mm6909e1.
World Health Organization. Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19) 16-24 February 2020. Geneva: World Health Organization; 2020.
Zhu N, Zhang D, Wang W, Li X, Yang B, Song J, et al
. A novel coronavirus from patients with pneumonia in China, 2019. N
Engl J Med 2020;382:727-33.
National Institute for Occupational Safety and Hygiene (NIOSH) NIOSH Guide to the Selection and Use of Particulate Respirators Certified Under 42 CFR 84. (DHHS (NIOSH) Publication no. 96-10. Cincinnati, Ohio, USA: National Institute for Occupational Safety and Hygiene (NIOSH); 1996.
MacIntyre CR, Seale H, Dung TC, Hien NT, Nga PT, Chughtai AA, et al
. A cluster randomised trial of cloth masks compared with medical masks in healthcare workers. BMJ Open 2015;5:e006577.
Milton DK, Fabian MP, Cowling BJ, Grantham ML, McDevitt JJ. Influenza virus aerosols in human exhaled breath: Particle size, culturability, and effect of surgical masks. PLoS Pathog 2013;9:e1003205.
Comparison of FFP2, KN95, and N95 and other filtering facepiece respirator classes. 3M Science, Revision 2. Techn Bull 2020;1-3.
Coia JE, Ritchie L, Adisesh A, Makison Booth C, Bradley C, Bunyan D, et al
. Guidance on the use of respiratory and facial protection equipment. J Hosp Infect 2013;85:170-82.
Rational use of Personal Protective Equipment for Coronavirus Disease 2019 (COVID-19). Interim Guidance. WHO/2019-nCoV/IPC PPE_use/2020.2.; 27 February, 2020.
Lee SA, Hwang DC, Li HY, Tsai CF, Chen CW, Chen JK. Particle Size-Selective Assessment of Protection of European Standard FFP Respirators and Surgical Masks against Particles-Tested with Human Subjects. J Healthc Eng. 2016;2016:8572493. doi:10.1155/2016/8572493.
[Table 1], [Table 2], [Table 3]