Q&A on novel coronavirus with expert

Chinese health authorities announced Monday that 20,438 confirmed cases of pneumonia caused by the novel coronavirus (2019-nCoV).

China’s State Council announced plans to extend the Lunar New Year holiday to Feb 2 as a key measure to control the novel coronavirus outbreak. According to the State Council notice, the start of the spring semester for all colleges, schools and kindergartens across the country will be suspended. The Education Department will issue separate notices about starting times.

Recently, Li Lanjuan, a member of the high-level expert team convened by the National Health Commission, and an academician with the Chinese Academy of Engineering, spoke with China Central Television about key issues of the novel coronavirus epidemic.

Q&A on novel coronavirus with expert
Q: Do people get infected during the incubation period of novel coronavirus?
A: I’ve been doing research on this and so far I have found that the virus is able to transmit during the incubation period. That’s why we put those having contact with infections within 14 days under medical observation and quarantine.

Q: Does the novel coronavirus only transmit through the respiratory tract?
A: The transmission through the respiratory tract is definite. Meanwhile, transmissions via blood, excrement and contaminated objects need to be verified.

Q: How do we distinguish between the common cold and novel coronavirus pneumonia?
A: The early symptoms of the two are similar, including fever, dry cough, respiratory symptoms, and fatigue after fever. Some even showed up in the digestive tract.
The most important way to distinguish it is by taking samples from throat swabs to test for the virus. The report clearly tells whether the tester is infected with H1N1, type B influenza or novel coronavirus. The reagent test kits are supposed to be accessible in designated hospitals.


Q: Can patients with milder symptoms stay at home for quarantine?
A: Recently a doctor reported he was cured by taking therapies at home on his own, which I think may work for him. As a doctor he knew medical knowledge and his own condition, so he didn’t fear the virus and had a good rest.
But it’s safer to go to hospital if you are lacking medical equipment, as a regular chest CT is needed to check if the infection is getting worse. If you are not medical personnel with a clear awareness of your physical condition and the inflammation develops quickly, you should go to a hospital for treatment.

Li Lanjuan also suggested that people try to avoid crowded places, wear masks outside, wash hands frequently and make sure your indoor air is circulating during Spring Festival.
At present, Jiangsu province has 28 designated hospitals for pneumonia treatment and 541 fever clinics.

N95, KN95, FFP2, P2 respirator face masks, what are their differences?

What are the N95, KNP5, FFP2, P2 ?

First of all, these are the standards of masks, not the brand of a certain mask, not the model of a certain mask, not the function of a certain mask, but the standard of a mask, which is a standard !

Different face mask standards in the world currently:

  • N95 (United States NIOSH-42CFR84)
  • FFP2 (Europe EN149-2001)
  • KN95 (ChinaGB2626-2006)
  • P2 (Australia/New Zealand AS/NZA1716:2012)
  • Korea 1st class (Korea KMOEL -2017-64)
  • DS (Japan JMHLW-Notification 214,2018)

What does these standards stand for ?


Certification/ Class (Standard)


N95 (NIOSH-42C




FFP2 (EN 149-2001)


KN95 (GB2626-20 06)



P2 (AS/NZ 1716:2012)

Korea 1st Class (KMOEL – 2017-64) DS (Japan JMHLW-

Notification 214, 2018)

Filter performance – (must be ≥ X% efficient) ≥ 95% ≥ 94% ≥ 95% ≥ 94% ≥ 94% ≥ 95%
Test agent NaCl NaCl and paraffin oil NaCl NaCl NaCl and paraffin oil NaCl
Flow rate 85 L/min 95 L/min 85 L/min 95 L/min 95 L/min 85 L/min
Total inward leakage (TIL)* – tested on human subjects each performing exercises N/A ≤ 8% leakage (arithmetic mean) ≤ 8% leakage (arithmetic mean) ≤ 8% leakage (individual and arithmetic mean) ≤ 8% leakage (arithmetic mean) Inward Leakage measured and included in User Instructions
Inhalation resistance – max pressure drop ≤ 343 Pa ≤ 70 Pa (at 30 L/min)

≤ 240 Pa (at 95 L/min)

≤ 500 Pa (clogging)

≤ 350 Pa ≤ 70 Pa (at 30 L/min)

≤ 240 Pa (at 95 L/min)

≤ 70 Pa (at 30 L/min)

≤ 240 Pa (at 95 L/min)

≤ 70 Pa (w/valve)

≤ 50 Pa (no valve)

Flow rate 85 L/min Varied – see above 85 L/min Varied – see above Varied – see above 40 L/min
Exhalation resistance – max pressure drop ≤ 245 Pa ≤ 300 Pa ≤ 250 Pa ≤ 120 Pa ≤ 300 Pa ≤ 70 Pa (w/valve)

≤ 50 Pa (no valve)

Flow rate 85 L/min 160 L/min 85 L/min 85 L/min 160 L/min 40 L/min
Exhalation valve leakage requirement Leak rate ≤ 30 mL/min N/A Depressurizatio n to 0 Pa ≥ 20 sec Leak rate ≤ 30 mL/min visual inspection after 300 L /min for 30 sec Depressurizatio n to 0 Pa ≥ 15 sec
Force applied -245 Pa N/A -1180 Pa -250 Pa N/A -1,470 Pa
CO2 clearance requirement N/A ≤ 1% ≤ 1% ≤ 1% ≤ 1% ≤ 1%


Filter performance – the filter is evaluated to measure the reduction in concentrations of specific aerosols in air that passes through the filter.

Test agent – the aerosol that is generated during the filter performance test.

Total inward leakage (TIL) – the amount of a specific aerosol that enters the tested respirator facepiece via both filter penetration and faceseal leakage, while a wearer performs a series of exercises in a test chamber.

Inward leakage (IL)– the amount of a specific aerosol that enters the tested respirator facepiece, while a wearer performs a normal breathing for 3 minutes in a test chamber. The test aerosol size (count median diameter) is about 0.5 micro meter.

Pressure drop – the resistance air is subjected to as it moves through a medium, such as a respirator filter.

Based above table, it is reasonable to consider China KN95, AS/NZ P2, Korea 1st Class, and Japan DS FFRs as “equivalent” to US NIOSH N95 and European FFP2 respirators, for filtering non-oil-based particles such as those resulting from wildfires, PM 2.5 air pollution, volcanic eruptions, or bioaerosols (e.g. viruses). However, prior to selecting a respirator, users should consult their local respiratory protection regulations and requirements or check with their local public health authorities for selection guidance.

Reference document: https://multimedia.3m.com/mws/media/1791500O/comparison-ffp2-kn95-n95-filtering-facepiece-respirator-classes-tb.pdf

Can disposable masks be reused? how to reuse disposable mask ?

Let’s start with the conclusion: reuse of disposable masks is not recommended in principle. However, the coronavirus disease has not yet been resolved, and there is a shortage of masks, which can still be reused in different occasions.

Protective principle of disposable masks: disposable masks are mostly made of polypropylene meltblown non-woven material. This material is an ultra-fine electrostatic fiber. The biggest feature is its electrostatic adsorption capacity. Disposable masks use the principle of electrostatic adsorption to adhere viruses and droplets to the masks, preventing them from entering the respiratory tract.

Therefore, in principle, disposable masks are recommended to be replaced after 4 hours. If you use them in places with a lot of viruses such as hospital, it is definitely not recommended to reuse them, and if necessary, you must replace them strictly every 4 hours. . Otherwise, there may already be a lot of viruses on the outer layer of the mask.

However, if it is an ordinary person, they don’t touch people with disposable masks, and they don’t have enough stocks of masks, and there is no way to buy disposable masks.  After scientifically disinfecting disposable masks, they can still be reused.

Scientific disinfection of disposable masks need to grasp two principles: one is high temperature and the other is anhydrous. Because static electricity is most afraid of water, fumigation with water vapor at high temperature is completely wrong. Once in contact with water, this mask has almost no protective effect. Disposable mask scientific disinfection method is dry heat disinfection method ( actually you can dry the maks with hair dryer in middle temperature for 10-20 seconds ) , the simplest way is to throw it in the tableware disinfection cabinet at home for UV disinfection.