WS/T 648-2019General hygienic requirement for air disinfecting machine (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This standard was drafted. Heilongjiang Provincial Center for Disease Control and Prevention, China Center for Disease Control and Prevention, Environmental and Health-related Product Safety Institute, Chinese People's Liberation Army Center for Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Jiangsu Provincial Health Supervision Institute, Hebei Province Disease Prevention and Control Center, Shandong Provincial Center for Disease Control and Prevention.

1 Scope

This standard specifies the classification, naming and model, technical requirements, inspection methods, of use, nameplates and instructions for air sterilizers.

This standard applies to air sterilizers that are sterilized using physical factors, chemical factors and other factors.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only the dated version applies to this document.

For undated references, the latest edition (including all amendments) applies to this document.

GB 9706.1 Medical electrical equipment - Part 1. General requirements for safety GB/T 14294 modular air conditioning unit GB 28232 Ozone Generator Safety and Hygiene Standard GB 28235 UV air sterilizer safety and hygiene standards GBZ/T 189.8 workplace physical factor measurement noise Disinfection Technical Specification (2002 Edition) Ministry of Health (Wei Fa Jian Fa [2002] No. 282) Management Specification for Labeling Instructions for Disinfecting Products (2005 Edition) Ministry of Health (Wei Supervision and Development [2005] No. 426)

3 Terms and definitions

The following terms and definitions apply to this document.

Air disinfecting machine Use physical, chemical or other methods to kill or remove microorganisms in indoor air, and to achieve disinfection requirements, with independent power, energy Stand-alone device.

Natural decay rate

The percentage of bacteria in the air that naturally decrease or naturally die.

Extinction rate

The percentage of bacteria in the air that are naturally decaying and disinfected.

Killing rate

In the microbial killing test, the percentage indicates the decrease in the number of microorganisms.

4 Classification

5 Name and model

6 Technical requirements

7 Detection methods

8 How to use

8.1 According to the instructions of the use of various air disinfection machines, the disinfection effect should meet the requirements of 6.5.

8.2 When using an air sterilizer to sterilize the intended disinfection site, it should be carried out in a closed environment to avoid circulation with outdoor air.

Ensure disinfection.

8.3 When using the ozone air disinfection machine to disinfect indoor air, the indoor relative humidity should be >=70% to ensure the disinfection effect.

8.4 When disinfecting indoor air with an air sterilizer that produces harmful substances such as chlorine dioxide, hydrogen peroxide, peracetic acid, or ozone, it should be carried out under unmanned conditions in the room. After the disinfection is finished, the indoor disinfection factor should be reduced until there is no impact on people (generally more than 30 minutes) can enter the person; when the situation permits, the window can be ventilated, so that the disinfection factor can be diffused and neutralized as soon as possible; pay attention to the protection of indoor items and avoid strong Damage to the item by the oxidant.

9 Nameplates and instructions

It shall comply with the provisions of the "Management Specifications for Labeling Instructions for Disinfecting Products".

Appendix A

(normative appendix) Air disinfection simulation field test A.1 Purpose the simulated test site air is contaminated by artificial spraying of microbial aerosols, and the air disinfection machine is used for air disinfection.

Low safe use of the dose.

A.2 Test equipment and equipment A.2.1 Test strain. Staphylococcus aureus 8032 strain.

A.2.2 Medium. nutrient broth medium, nutrient agar medium, nutrient agar medium containing neutralizer (containing neutralizing agent for attachment) those who have passed the C identification are sampled after disinfection of the air disinfection machine for chemical disinfection factors).

A.2.3 Aerosol chamber for disinfection test. The aerosol chamber should be constructed of smooth, corrosion-resistant and easy-to-clean materials such as stainless steel, aluminum alloy and glass.

A pair of neighbors (both volumes of 20 m3), one for the disinfection test and the other for the test control. The environment in which a pair of aerosol chambers are located (including temperature Degree, relative humidity, light, airtightness, ventilation, etc.) should be consistent. Temperature and relative humidity regulators and ventilator filters should be installed Sterile or other disinfection devices and corresponding pipelines, such as sleeve operation and sample delivery for spray sterilization, drug administration, sampling, etc.

A.2.4 Spraying equipment, including air compressors, pressure gauges, gas flow meters and aerosol sprayers. Spraying bacteria aerosol micro the diameter of the granules should be 90% or more and should be between 1 µm and 10 µm.

A.2.5 Air microbial sampling device. Six-stage mesh air impact sampler, air extraction equipment, gas flow meter, timer, etc.

A.2.6 Environmental monitoring equipment. thermometers, hygrometers, etc.

A.3 Preparation of test bacterial suspension Take fresh stabbed cultures of Staphylococcus aureus from 3rd to 7th generations at 36°C±1°C for 18-24 hours, using TPS (trypeptone saline) Solution) Wash the lawn, filter it with sterile cotton wool, and dilute it to the desired concentration with nutrient broth.

A.4 operating procedures A.4.1 Installation of the air sterilizer to be tested Before the test starts, install the air disinfection machine to be tested at the far end of the test aerosol chamber according to the installation instructions of the air disinfection machine to be tested.

The source is confirmed to be able to work normally, and in the control aerosol chamber, the air disinfection capability is removed and compared with the equipment of the same type to be tested.

Then close the door. Thereafter, all operations and equipment are operated outdoors through a window or remote control with a sealed sleeve. straight the door can only be opened until the end of the test.

A.4.2 Test environment condition setting Turn on the computer control system (or turn on the temperature and humidity adjustment device), and adjust the temperature and relative humidity of the two aerosol chambers to the test.

Required temperature (20 ° C ~ 25 ° C) and relative humidity (50% ~ 70%).

A.4.3 Aerosol spray staining the microbial aerosol generator was fixed on the sampling vehicle in the control and test group aerosol chambers and placed in the center of the aerosol chamber.

The position is 1.0 m from the ground, and the bacteria are sprayed according to different aerosol generating devices to set the pressure, gas flow rate and spray time. Spraying Stir the bacteria with a fan (mixer). After the spray was dyed, the mixture was stirred for 5 min and allowed to stand for 5 min.

A.4.4 Sampling before disinfection After 5 min of rest, the aerosol chambers of the control group and the test group were separately sampled before disinfection, as the control group before the start of the test and the test.

The positive control (ie, the amount of contaminated bacteria) before the group was disinfected. The number of positive control bacteria in the indoor air of aerosol should reach 5x104 CFU/m3~5x105 CFU/m 3 (The number of positive control bacteria in the control group at the last time of the disinfection test shall not be less than 5x104 CFU/m3).

A.4.5 Disinfection treatment According to the instructions for use of the air sterilizer to be tested, start up and run.

A.4.6 Sampling after disinfection the air sterilizer is applied to the first scheduled time (0.5 times of the specified time), and is immediately the same for the test group and the control group.

Sampling is performed; the action is continued until the second predetermined disinfection time (the time specified in the manual), and sampling is performed again as described above.

A.4.7 Sampling requirements the test uses a six-stage sieve air impingement sampler for sampling. When sampling, a six-stage sieve air impingement sampler is placed in the center of the aerosol chamber.

At a height of 1.0 m, the sampling flow rate is 28.3 L/min, and the sampling time is determined according to the prediction test (the general control group and the test group are sampled before the disinfection treatment).

5 s ~ 10 s, the disinfection effect of the test group after disinfection, such as disinfection qualified sampling 5 min ~ 10 min).

A.4.8 Cultivation and observation of results After sampling, the plate was taken out aseptically and placed in a 36 ° C ± 1 ° C incubator for 48 h for viable culture counting. After completing the test group and being positive After the control group was sampled, the same batch of the unused medium was cultured simultaneously with the above two groups of samples as a negative control. If the negative control group has bacteria Growth, indicating that the medium used is contaminated, the test is invalid, and the replacement of the sterile equipment is repeated.

A.4.9 Disinfection of aerosol chamber After the whole test is completed, after the final disinfection of the bacteria on the surface of the aerosol chamber and the air, the fan is turned on, and the bacteria are removed and filtered.

In addition to polluted air trapped inside the aerosol chamber.

A.5 Data Processing

A.5.1 Calculation of bacteria content in the air the amount of bacteria in the air is calculated according to formula (A.1).

T3.28

X (A.1)

In the formula.

X--Air bacteria, in units of colony forming units per cubic meter (CFU/m3);

S--the total number of bacteria on the six-stage sampling plate, the unit is the colony forming unit (CFU);

t--Sampling time in minutes (min).

A.5.2 Calculation of kill rate the disinfection effect of the air disinfection machine on the bacteria is determined by the kill rate (or clearance rate) Kt, and the value is expressed by (%), and is calculated according to the formula (A.3).

N tt (A.2)

VNV

K (A.3)

In the formula.

Kt--killing rate (or clearance rate) of bacteria in the air, %;

V0' and Vt'--the air-containing bacteria in the test group before and during the disinfection process, the unit is the colony forming unit per Cubic meters (CFU/m3);

Nt--the natural decline rate of bacteria in the air;

V0 and Vt--the amount of bacteria in the air before the start of the test and at different times during the test, in units of colony forming units Square meter (CFU/m3).

A.6 Repeat test

The test was repeated 3 times in the same condition.

A.7 Result determination the killing rate (or clearance rate) of the three test results was >=99.9%, which was judged to be qualified for disinfection.

A.8 Precautions

A.8.1 In the test, because the conditions for uniform control are difficult, it is necessary to set the test group and the control group at the same time in each test.

Consistent.

A.8.2 Note the temperature and relative humidity during the test to record the comparison.

A.8.3 The sample should be microbiologically tested as soon as possible to avoid affecting the accuracy of the results.

A.8.4 The aerosol chamber should be adequately ventilated after each test. Disinfect and rinse if necessary, and the second test can be done after 4 hours.

A.8.5 During the test, the aerosol chamber must be kept closed and equipped with an air filter to prevent the contaminated air from polluting the environment.

A.8.6 During the test, the aerosol chamber should be protected from direct sunlight to avoid bactericidal instability.

A.8.7 The filter material in the air chamber exhaust filter device should be replaced regularly. The replaced filter material should be sterilized before other treatment.

Appendix B

(normative appendix) Air disinfection field test B.1 Purpose at the applicable site, in the absence of human conditions, natural bacteria are used as indicator microorganisms, and disinfection sites (such as wards, bedrooms, offices, etc.) can be sealed.

The location of the air disinfection or microbial removal treatment, verify the practical disinfection effect of the air disinfection machine.

B.2 Test equipment and equipment B.2.1 medium Nutrient agar medium, nutrient agar medium containing neutralizer (the neutralizing agent included is qualified according to Appendix C, used for chemical disinfection) Factor air sterilizer is sampled after disinfection).

B.2.2 Air microbial sampling device Six-stage mesh air impact sampler, extraction equipment, gas flow meter, timer, etc.

B.2.3 Environmental monitoring equipment Thermometer, hygrometer, etc.

B.3 Operating procedures B.3.1 Test site selection According to the requirements of the air disinfection machine, select a representative test site (such as ward, bedroom, office, ambulance, etc.) Closed place), and the amount of bacteria in the test site should be >=1000 CFU/m3, and the test should be carried out in the absence of indoors.

B.3.2 Installation of air disinfection machine to be tested Before the start of the test, install the air sterilizer to be tested at the remote end of the selected test site according to the installation instructions of the air sterilizer to be tested.

Good power and confirm that it works.

B.3.3 Sampling before disinfection After the air in the selected closed test site is static for 5 min, the natural bacteria in the air are sampled with a six-stage mesh air impact type sampler.

Pre-disinfection sample (positive control), when sampling, the test site <=10 m2 set a sampling point, the test site >=10 m2, each increase 10 m

2 Add one sampling point and set up to 5 sampling points. One sampling point sampling, the six-stage mesh air impact type sampler is placed in the test site at a height of 1.0m in the center, multiple sampling points place the six-stage mesh air impingement sampler on the diagonal or evenly distributed in the plum blossom, and away from disinfection.

The air outlet of the machine should be >0.5 m from the wall and sampled at a height of 1.0 m. The sampling flow rate is 28.3 L/min, and the sampling time is based on air.

The amount of bacteria is determined, generally not more than 10 minutes.

B.3.4 Disinfection treatment According to the instructions for use of the air sterilizer to be tested, start up and run.

B.3.5 Sampling after disinfection the air sterilizer is applied to the predetermined time (the time specified in the manual), and the sampling point is pre-sterilized with six-stage mesh air impingement sampling.

The same method is used to sample natural bacteria in the air as a test sample after disinfection.

B.3.6 Cultivation and observation of results After sampling, the plate was taken out aseptically and placed in a 36 ° C ± 1 ° C incubator for 48 h for viable culture counting. At the same time, the same batch of unused the nutrient base was cultured simultaneously with the above two groups of samples as a negative control. If the negative control group has bacteria growth, the medium used is contaminated.

The test is invalid and will be re-executed after replacement.

B.3.7 Repeated test

The test was repeated 3 times.

B.4 Data Processing

B.4.1 The amount of bacteria in the air is calculated as in A.5.1.

B.4.2 Calculation of the death rate the disinfection effect of the air disinfection machine on the natural bacteria in the air is measured by the death rate. The value is expressed in (%) and is calculated according to the formula (B.1).

100x

X (B.1)

In the formula.

X--death rate, %;

A--the average number of bacteria in the sample before disinfection, the unit is the colony forming unit per cubic meter (CFU/m3);

B--The average number of bacteria in the sample after disinfection, the unit is the colony forming unit per cubic meter (CFU/m3).

B.5 Result determination the rate of death of natural bacteria in each test was >=90.0%.

B.6 Precautions

B.6.1 In the test, the conditions for uniform control are difficult, so the environmental conditions before and after disinfection and between different times should be kept as consistent as possible.

B.6.2 Note the temperature and relative humidity during the test to record the comparison.

B.6.3 The on-site room should be protected from direct sunlig...