An Epidemiological Investigation on Correct Wearing of Mask by Direct Spray Test
Conditions: Respiratory Infectious Diseases
Sponsor: Fuwai Yunnan Cardiovascular Hospital

 
 
 
An Epidemiological Investigation on Correct Wearing of 
Mask by Direct Spray Test 
 
Program 
 
Program No：2020-KZLXB-02-01 
Version Date：August 20, 2020 
Version No:   version 2.0 
 
 
Research Unit（Seal）：Fuwai Yunnan Cardiovascular Hospital 
 
 
 
Research time: June 2020 to August 2020 
 
 
 

 
 
 
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Program outline 
Research 
title 
An Epidemiological Investigation on Correct Wearing of Mask by Direct Spray Test 
Population  
Those who are 7 years old or above, have the ability of autonomous behavior and 
language expression, are willing to take the test. 
Research 
center 
Responsible organization：  
Research site 1：Kunming 
Research site 2：Shizong 
Research site 3：Luliang 
Research site 4：Luoping 
Research site 5：Beijing 
Research site 6：Yuncheng 
Research site 7：Jinzhong 
Research site 8：Taizhou 
Research 
purpose 
To explore the relationship between the transmission of respiratory diseases and the 
correct wearing of masks, as well as the factors affecting the correct wearing of 
masks, an investigation and intervention study will be carried out. 
1. Investigate the proportion of people who wear masks correctly. 
Subgroup analysis: age, sex, education level. 
2. Can the adhesive strip above the mask effectively improve the protection rate? 
If the efficiency is significantly increased after the use of adhesive tape (such as ≥ 
95%), is there no need to change the hood test? 
3. Is "surgical mask + tape" a more effective measure? 
Research 
design 
1. Overall design：This study uses the methods of cross-sectional survey and 
chance sampling. 
2. Sign the Informed Consent Form. 
3. Investigation on the basic situation of personnel: The gender, age and 
education level of the subjects were analyzed as the factors influencing whether 
the mask was worn correctly or not. 
4. Investigation on the types and duration of wearing masks： 

 
 
 
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1) The types and duration of masks worn by the subjects were recorded as the 
basis of stratified statistics. 
2) Mask suitability testing： 
（1）Visual inspection 
whether the mask is close to the face with obvious gaps. 
（2）Breathing test 
Are there any obvious gaps or whether the cotton around the mask is blown 
when the subject taking a deep breath. 
（3）Spray test 
The FT-30 qualitative fitness test system of 3M company was used to test the 
suitability and correctness of wearing mask. 
In the spray test, all subjects underwent a sensitivity test to prove their ability to 
smell the bitterness of the reagent, sensitive subjects can participate in the direct spray 
test. 
The process is as follows: 
1. Sensitivity test: the subjects will not wear a mask, but put on a hood, open 
their mouth to breathe, and extend their tongue properly. Spray the 
sensitivity reagent (the diluent of the fitness test reagent) 10 times and ask 
the subjects if they feel bitter, and if they have, record it. If there is no 
feeling, spray 10 more times to see if there is a feeling. If you need to spray 
another 10 times, record the subjects' sensation during 20 or 30 times of 
spray. If there is no feeling for 30 times of spray and the test is over, the 
subject is not suitable for the test method. The subjects took off the hood and 
drank water to make the bitterness disappear. 
2. After drinking water to eliminate bitterness, sensitive subjects will 
participate in the direct spray test. 
3. The process of direct spray test: 
1) The subject wears a mask and his/her tongue sticks out properly. The 
suitability test reagent is used to spray directly to the subject from the top, 
bottom, left side and right side twice respectively, and the subject can stop 

 
 
 
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the spray as soon as he/she smells bitterness. 
2) Record whether the subject feels bitterness, if not, let the subject puts on 
the hood, carry out the fitness test again and record the results. 
3) If the subject feels bitterness, stick the adhesive strip on the upper edge of 
the subject's mask and perform the direct spray test again. Record whether 
the subject feels bitterness, if not, ask the subject to put on the hood, carry 
out the fitness test again and record it. If there is a feeling, ask the subject 
to change to a medical surgical mask and put an adhesive strip on the upper 
edge of the mask, then conduct the direct spray test again, and record the 
test results. 
Selection 
criteria 
1) Healthy people with autonomous behavior ability and language expression 
ability who are older than or equal to 7 years old, Persons under the age of 18 
need to obtain the consent of their legal guardians； 
2) The subjects and / or their legal guardians have the ability to understand the 
contents of the study and to participate in all the research processes with the 
subjects； 
3) People who volunteered to take part in the study； 
4) There was no respiratory infection in nearly one month. 
Exclusion 
criteria 
1) People with a history of allergies, including those who are allergic to pollen, dust 
mites, etc； 
2) People with any history of drug allergy； 
3) People who have participated in the experiment are not allowed to participate in 
this study for the second time; 
4) Pregnant women； 
5) The healer after COVID-19 's infection； 
6) After questioning, it was found that the subjects were the factors that affected 
the study, such as dysosmia, or those who had decreased olfactory ability due to 
disease, or facial paralysis, which affected the judgment of the test； 
7) Those who are participating in clinical trials of other drugs / devices； 
8) Subjects with poor compliance or unwilling to cooperate with the operation as 

 
 
 
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required； 
9) The researchers believe that any other situation that may affect the evaluation of 
the study. 
Elimination 
standard 
1）Subjects with incomplete information collection; 
2）Subjects who have participated in the experiment twice (if the first data collection 
is available, the second data is excluded). 
Related 
reagent 
information 
Common name：Trinitrophenol 
Production unit：3M company 
Specification：55ml 
Active ingredient： 2，4，6- trinitrophenol 
Other ingredients：water dilution 
Research 
end point 
Collect survey data with sufficient sample size. 
Sample size 
consideratio
n 
In order to objectively reflect the overall situation of the subjects, it is necessary to 
cover many ages and educational levels of men and women. 
Research 
duration 
Each subject participated in the study for about 5-6 minutes, and the total duration of 
this study was about 4 months. 
Statistical 
analysis 
Results were statistically analyzed by SPSS software. 
 
 

 
 
 
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Research flow chart 
 
 
 
 

 
 
 
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1、Purpose and significance 
The purpose of this study was to explore the relationship between the transmission of 
respiratory diseases and the correct wearing of masks, as well as the factors affecting the correct 
wearing of masks. The research is beneficial to the prevention of respiratory diseases and moves 
the barrier of prevention and control forward. It is of great significance to COVID-19 's practical 
prevention and control. 
2、Research design 
（1）Overall design： 
1、Selection methods 
This study uses the methods of cross-sectional survey and chance sampling. 
2、Sign the informed consent form. 
3、Investigation on the basic situation of personnel 
The gender, age and education level of the subjects were analyzed as the factors 
influencing whether the mask was worn correctly or not. This study is an anonymous survey 
and does not collect personal information other than the subjects' names and the above-
mentioned information. 
4、Investigation on the types of wearing masks 
The types of masks worn by the subjects were recorded as the basis of stratified statistics. 
5、Mask suitability testing： 
（1）Visual inspection：whether the mask is close to the face with obvious gaps. 
（2）Breathing test：are there any obvious gaps or whether the cotton around the mask is blown 
when the subject taking a deep breath. 
（3）Spray test：The FT-30 qualitative fitness test system of 3M company was used to test the 
suitability and correctness of wearing mask. 
In the spray test, all subjects are required to undergo a sensitivity test to prove their ability 
to smell the bitterness of the reagent, and then sensitive subjects will participate in the direct 
spray test, as shown in the flow chart. For the specific operation of FT-30 qualitative suitability 
testing equipment, see Attachment 1. 
6、If the subject wears the mask incorrectly, correct the way the mask is worn. 
A、Training participants who wear the mask incorrectly on the correct way to wear masks  

 
 
 
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（1）Demonstrate the correct way to wear disposable medical masks： 
1) wash your hands and check the validity and packaging of the mask. 2) the side of the 
nose clip is facing up and the dark face is facing outward. If there is no color difference, it is 
judged from the fold of the mask, and the downward part of the fold is on the outside. 3) pull 
the wrinkles up and down, cover the mouth, nose and jaw with a mask, and wrap the whole 
chin. 4) the fingertips of both hands are gradually moved outward to the medial contact pressure 
nose clip. 5) when taking off the mask, one hand hooks it off at the place where the mask is tied. 
（2）The correct way to wear an N95 mask： 
1) Face the mask without a nose clip so that the nose clip is above the mask, hold the mask 
on your face and hold it against your chin. 2）pull the upper headband over the top of the head 
and place it above the top of the head. 3）pull the lower headband over the top of the head and 
place it under the back of the neck and the ear.4）place your fingers in the middle of the metal 
nose clip, press inward and move your fingertips along both sides of the nose clip until the nose 
clip is completely pressed into the shape of the bridge of the nose. Squeezing the mask nose 
clip with only one hand may affect the tightness of the mask. 5）the user must check the 
closeness of the mask to the face and cover the mask with both hands to avoid affecting the 
position of the mask on the face. You can inhale quickly. If air leaks from the bridge of the nose, 
you should re-adjust the nose clip according to step 4. If the air leaks from the edge of the mask, 
the headband should be readjusted. If a good fit cannot be obtained, repeat steps 1) to 4). If you 
do not feel the leak, you should wear it well. 
B、Check the tightness again after correcting the way the mask is worn. 
（1）The liquid spraying experiment verifies the correctness of the mask wearing after 
correcting the wearing mode. 
Ask the subjects to wash their mouths with unified mineral water. After a 1-2 minute rest, 
there is no difference in the mouth, and then use FT30 qualitative fitness testing equipment to 
test the suitability of the mask to see if the subjects smell peculiar smell or bitter taste in the 
mouth. 
After all the studies are completed, the research team will provide the subjects with a new 
medical aseptic mask. 
3、Statistical analysis 

 
 
 
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The results were analyzed by SPSS software. 
4、Subject protection 
The subjects should take this test of their own free will, and they can withdraw from the 
test at any time for any reason, and will not cause any adverse effect on the subjects. Before 
participating in the study, the subjects or minor subjects' legal guardians will be fully informed 
of the informed consent of this study and sign the informed consent form. 
1、Protection of the rights and interests of minors and children with amblyopia 
If the subjects are under 18 years old (excluding 18 years old) to participate in this test, 
the school will seek the consent of the legal guardian (parents) on behalf of the school, and the 
medical staff can also demonstrate the testing process by video. after letting the minors know 
and fully understand, if they agree to the test, they and the guardian need to sign and agree to 
participate. 
2、Subject information confidentiality  
This test will not collect any personal privacy-related information of the subjects, does not 
involve the disclosure of the subjects' personal identity information (for example, name or 
address), and will not infringe upon the subjects' privacy. The medical data from the subjects 
and the records of participating in this trial will be submitted to the research party and kept in 
a secure repository to control the data. The personal data of the subjects collected during the 
test may be transmitted to Fuwai Hospital of the Chinese Academy of Medical Sciences, located 
at 167 Beilishi Road, Xicheng District, Beijing. The results of this study will be used for 
experimental reports, article publication and policy research. 
5、The scientific research ability of the research unit 
Yunnan Fuwai Hospital is a public third-class specialized hospital jointly built by Fuwai 
Cardiovascular Hospital of Chinese Academy of Medical Sciences and Yunnan Provincial 
Government, which integrates medicine, teaching and research. It is also the only third-class 
cardiovascular hospital in southwest China. It has been approved Yunnan Cardiovascular 
Disease Clinical Medical Center, National Arrhythmia intervention Engineering and 
Technology training Base, and national postdoctoral research station. National New Drug 
Clinical Phase I observation Base, Kunming Medical University doctorate and Master's degree 
Award Point, Yunnan Heart failure diagnosis and treatment Innovation team, Yunnan pacing 

 
 
 
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patient follow-up platform, Yunnan Atrial Fibrillation cryoablation collaboration Network, 
Yunnan Hypertension Prevention and Control Center, Cardiovascular Disease Rehabilitation 
Center. 
At present, the hospital has been approved a number of construction projects, such as the 
national project to improve the ability of diagnosis and treatment of difficult diseases, Yunnan 
Clinical Medical Center, Yunnan Heart failure Innovation team and so on. Access to external 
support funds of nearly 200 million yuan. At the same time, our hospital has also been approved 
to become a national medical device and drug clinical trial institution, actively carrying out 
clinical research work. At the same time, the hospital actively declared all kinds of scientific 
research projects at all levels. Nearly three years after its establishment, the hospital was newly 
approved to preside over 22 scientific research projects at all levels, with a scientific research 
funding of 4.95 million yuan. Under the leadership of the leaders of various disciplines, his 
team completed 24 innovative technologies in our hospital, including the first case in the world, 
the first case in southwest China, and the first case in Yunnan Province, including magnetic 
levitation left heart assist device, aortic arch covered stent system to repair the dissection of the 
arch, total thoracoabdominal aortic replacement under normal temperature and off-pump, and 
continuous coronary artery bypass grafting and intracavitary repair of abdominal aortic 
aneurysm at the same time. Simultaneous endovascular repair of complex aortic dissection and 
coronary stent implantation, and simultaneous PDA occlusion and external windowing for 
thoracic aortic aneurysm.  
 

 
 
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Attachment 1 
Operating rules for FT-30 qualitative suitability testing equipment 
(bitterness) 
 
(1) Application:  
It is used to test the facial fitness of tight-fitting respiratory protector to the wearer, it is 
suitable for all dust masks / masks and gas masks / masks equipped with particulate pre-filter 
cotton. 
(2) Reagent ingredients:  
water, sodium chloride, Denatoniumbenzoate  
(3) Note:  
Denatoniumbenzoate is a very bitter chemical, so be careful not to let children come into 
contact with it. 
If there are signs of contamination in the reagent, pour the reagent away immediately.  
According to the OSHA regulations of the US Occupational Safety and Health 
Administration, the tested person should be informed of the composition of the test reagent 
before the fitness test, and the test object will be exposed to a fine spray of the reagent during 
the test. 
If crystallization occurs in the reagent, tighten the opening of the reagent bottle, soak it 
in warm water, or shake hard to dissolve the crystal. 
The 3M TMFT-30 qualitative fitness testing equipment (bitterness) meets the relevant 
provisions of OSHA respiratory protection standard 29CFR1910.134 for fitness testing.  
(4) Preparation:  
1. Put the hood on the collar, align the center of the window of the hood with the round 
hole on the collar, and tighten the rope on the hood and tie the knot. 
2.Pour about 1 teaspoon # 1 reagent into the # 1 sprayer.  
3. Pour the same amount of # 2 reagent into the # 2 sprayer.  
4. Tighten the lid of the reagent bottle immediately.  
(5) Sensitivity test: 
The purpose of the sensitivity test is to determine whether the subject can feel the 
reagent used. The sensitive reagent is the diluent of the reagent used in the suitability test. The 
subjects are not allowed to eat, drink (except water) or chew gum 15 minutes before the test. 
1. Don't wear a mask, put on a hood. 
2. Adjust the position of the hood so that there is a distance of more than 10 centimeters 
between the subject's face and the window of the hood. 
3. Subjects are asked to open their mouths to breathe and stick out their tongues properly. 
4. Remove the # 1 sprayer nozzle seal cover, insert the nozzle into the round hole in the 
window, compress the airbag and spray 10 times. The airbag should be completely flattened 
each time it is sprayed, and then allow it to expand completely. The sprayer must be in a 
vertical position with the airbag facing down. 

 
 
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5. Ask the subject if he or she feels bitterness, and if so, record the subject's feeling of 
bitterness during 10 sprays. 
6. If there is no feeling, spray 10 more times to see if the subjects feel. If you need to 
spray 10 more times, record that the subjects feel the spray 20 or 30 times. 
7. If there is still no feeling after 30 times of spray, the test is over, indicating that the 
subject should choose other fitness test methods. 
8. Take off the hood and let the taste disappear from the subjects' mouths. Drinking water 
can help the taste disappear. 
(6) Fitness test: 
1. After the subjects put on the mask and wear the mask correctly, the facial tightness test 
is performed to ensure the closeness. 
2. Use the # 2 sprayer and spray once. 
3. After spraying, the subjects are asked to do the following actions  
a. Normal breathing---standing posture, normal breathing rate, do not speak.  
b. Take a deep breath---stand up, take a slow, deep breath, and be careful not to exhale 
too much.  
4. Whenever the subject feels bitter, it means that the mask does not fit well with the 
subject's face, and stop the fitness test.  
5. The fitness test is repeated after the subjects readjusted or wore a new mask. If it tastes 
bitter again, it means the subjects need other types of masks.  
6. If the subjects do not feel bitter all the time, it means that the mask is suitable for the 
subjects' face and can be worn.  
7. Regularly check the sprayer, if there is a blockage, remove the blockage phenomenon, 
repeat the fitness test.  
(7) Inspection equipment includes:  
 #1 sprayer (sensitivity test) 1  
 #2 sprayer (fitness test) 1  
 spray nozzle spare parts 2 sets  
 #2 fitness test reagent one bottle  
(8)、Equipment cleaning:  
After each inspection, or after at least 4 hours of use, pour out the reagent in the sprayer. 
Never pour the remaining reagents back into the original bottle. Wash the sprayer with 
warm water to prevent the nozzle from clogging and air-drying. Wipe the inside of the hood 
with a wet towel or paper towel to remove aerosols deposited on it. For mask type masks, you 
can wipe the mask with 3MTM mask wipes 504 after each fitness test. 
 
 
 

 
 
 
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Attachment 2 
Inspection record of qualitative suitability of close-fitting mask 
（page:  total page:   ） 
Fitness test time：                         Inspection equipment:  
Serial 
number Gender 
Age 
Culture 
Type and duration of mask 
Mask suitability test 
 
General 
medical 
masks 
Medical 
surgical 
masks 
Medical 
protective 
masks 
Particulate 
matter 
protective 
mask 
Warm 
cloth 
mask 
Visual 
inspection 
Breathing  
test 
 
Spray test 
 
Sensitivity 
test 
 
Direct 
spray  
test 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Note: qualitative suitability test: according to whether the bitter taste is felt, it is recorded as-not felt, + as felt. 

 
 
 
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Connect to the previous page 
Inspection record of qualitative suitability of close-fitting mask 
（page:  total page:   ） 
Fitness test time：                         Inspection equipment:  
 
Serial 
number 
Gender 
Age 
Culture 
Direct spray test 
Can’t fell: 
Wear a hood  
 
 
 
Can fell 
 
 
Can fell: 
Strip 
 
 
Can’t fell: 
Wear a hood  
 
 
Can fell 
 
Can fell: 
Medical 
mask+strip  
 
 
Can fell 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Note: qualitative suitability test: according to whether the bitter taste is felt, it is recorded as-not felt, + as felt.