Decision No. 870/QD-BYT dated March 12, 2020 on Temporary technical guidelines for fabric anti-droplet and bacteria prevention facemasks

DECISION

ON TEMPORARY TECHNICAL GUIDELINES FOR FABRIC ANTI-DROPLET AND BACTERIA PREVENTION FACEMASKS

MINISTER OF HEALTH

Pursuant to Decree No. 75/2017/ND-CP dated July 20, 2017 of Government in functions, tasks, powers and organizational structure of Ministry of Health.

Pursuant to Decision No. 173/QD-TTg dated February 1, 2020 of Prime Minister on declaration of acute pneumonia due to novel Corona virus;

At the request of Director General of Department of Medical Equipment and Health Works – Ministry of Health,

HEREBY DECIDES:

Article 1. Attached to this Decision are “Temporary technical guidelines for fabric anti-droplet and bacteria prevention face masks”.

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Article 3. Chief of Ministry Office, Director General of Department of Medical Equipment and Health Works, Chief Ministry Inspectorate, Directors and Directors General of Departments and Agencies affiliated to Ministry of Health, Director of Institute of Medical Equipment and Health Works and heads of relevant entities are responsible for implementation of this Decision./.

PP. MINISTER
DEPUTY MINISTER




Truong Quoc Cuong

GUIDELINES

TEMPORARY TECHNICAL GUIDELINES FOR FABRIC ANTI-DROPLET AND BACTERIA PREVENTION FACE MASKS
(Attached to Decision No. 870/QD-BYT dated March 12, 2020 of Minister of Health)

1. Scope

These Guidelines apply to fabric anti-droplet and bacteria prevention face masks.

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2. Reference documents

Following reference documents are necessary for these Guidelines:

TCVN 8389-1:2010 Medical face mask – Part 1: Normal medical face masks.

TCVN 8389-1:2010 Medical face masks – Part 2: Medical face mask preventing bacteria.

3. Technical requirements

3.1. General provisions

- Face masks must not cause any allergic reactions to the wearers;

- Surfaces of face masks must be clean, free of snags, pills and having no visual flaws:

- Ear bands must be firmly structured;

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3.2. Structure and requirements for materials

3.2.1. Structure:

- At least 3 layers: the outermost layer must be water proof, preventing droplets or combined with preventing bacteria; other layers are filter and antibacterial layers (the bacteria prevention layer shall be made from antibacterial fabric, silver nano, activated carbon or equivalent materials);

- Ear bands;

3.2.2. Requirements for materials

3.2.2.1. The outer layers must be smooth, airy, water proof and capable of preventing respiratory droplets.

3.2.2.2. The antibacterial layer for preventing bacteria.

3.2.2.3. The filter layer must be layer airy and dust resistant.

3.2.2.4. Ear bands: made of elastic materials, namely rubber bands to aid and guarantee wearing and taking off of face masks.

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3.3.1. Droplet resistance: Filtering capacity for aerosol in 30 l/min flow rate must not be lower than 90% (testing method under Section 2.1 of Annex);

3.3.2. Breathing resistance: Breathing resistance in 30 l/min flow rate must not be lower than 9 mm water (testing method under Section 2.1 of Annex);

3.3.3. Antibacterial property:  The antibacterial property of fabric face masks shall be identified according to declaration of manufacturers (with experiment results attached).

3.3.4. Permissible limit of heavy metal elements in non-woven fabric; Conform to Article 3.5 - TCVN 8389-1 (may accredit equivalent experiment results under Section 2.3 of Annex).

4. Packaging and labelling

4.1. Packaging

According to declaration of manufacturers, individual packaging is recommended, ensuring sterility of face masks when packaging.

4.2. Labelling

- Comply with applicable regulations and law on product labelling.

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ANNEX

TESTING METHOD

1. Testing structure and requirements of materials

Examine structure and requirements of materials visually.

2. Testing technical requirements of face masks

2.1. Testing filter capacity

2.1.1. Principles

Determine filter capacity between input and out of specimen upon introducing particles with defined size.

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- Airtightness;

- Flow rate meter (5) with measurement range from 0 l/min to 60 l/min with accuracy of ± 0.1 l/min;

- Particle generators for diameter d ranging from 0.3 μm to 10 μm

- Particle counter and measuring devices.

- Specimen clamp.

2.1.3. Preparing specimen and equipment

- Specimen must be tight upon use, no flaws or defects;

- Prepare at least 3 specimen;

- Specimen shall be assigned with ordinal numbers;

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- Examine tightness of the equipment;

2.1.4. Execution

2.1.4.1. Testing conditions

- Testing equipment must be tight;

- Air flow passing through specimen shall be 30 l/min;

- Conduct tests in room temperature;

- Particles shall have diameter d and size ranging from 0.3 μm to 10 μm

2.1.4.2. Measure

- Place specimen in the clamp;

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- Determine measurement before the specimen with flow rate of 30 l/min, record the result (A_t);

- Remove the specimen from the clamp (9), place another specimen and continue the test

2.1.5. Calculate result

2.1.5.1. Filter capacity

H=100-(A_s/A_t x 100)

in which:

H refers to filter capacity, in percentage (%);

A_s refers to measurement reading behind the specimen;

A_t refers to measurement reading before the specimen;

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2.2. Testing breathing resistance

2.2.1. Principles

Determine differences in pressure between specimen input and output upon introducing air flow with determined flow rate.

2.2.2. Equipment and tools

2.2.2.1. Equipment for testing breathing resistance of devices protecting respiratory organs (Figure 2) must satisfy following requirements:

- Ensure airtightness;

- Flow rate meter (3) must have measurement range from 0 l/min to 60 l/min with accuracy of 0.1 l/min;

- Pressure gauges (5) with measurement range from 0 mmH₂O to 50 mmH₂0 with accuracy of 0.5 mmH₂0;

- Clamp (4) to ensure tightness with dimension and shape suitable for the specimen;

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- Prepare at least 3 specimen;

- Specimen must be tight upon use, without flaws or defects;

- Specimen shall be assigned with ordinal numbers;

- Place the specimen in the specimen clamp (4) while ensuring tightness;

2.2.3. Execution

2.2.3.1. Test conditions

- Equipment must be tight;

- Flow rate of air flow passing through specimen: 30 l/min;

- Conduct tests at room temperature;

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2.2.3.2. Determine resistance of equipment (P₁)

- Introduce air;

- Adjust valve (1) slowly until reaching flow rate of 30 l/min, record P₁ value on pressure gauge (5);

- Close air input.

2.2.3.3. Determine resistance (P₂)

- Place the specimen in the clamp (4);

- Introduce air;

- Adjust valve (1) slowly until reaching flow rate of 30 l/min, record P₂ value on pressure gauge (5);

- Close are input;

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2.2.4. Calculate result

2.2.4.1. Resistance of specimen in test conditions with flow rate of 30 l/min.

ΔP = P₂ - P₁

in which:

ΔP refers to resistance of specimen in test conditions, in mmH₂O;

P₂ refers to resistance of the equipment with presence of specimen, in mmH₂O;

P₁ refers to resistance of the equipment without the specimen, in mmH₂O.

2.2.4.2. Breathing resistance of devices protecting respiratory organs shall be average value of 3 specimen in the same test conditions.

2.3. Testing heavy metal elements in fabric

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Dissolve heavy metal in fabric specimen with hydrochloric acid. Determine heavy metal elements via atomic absorption spectroscopy or high frequency inductively coupled plasma.

2.3.2. Equipment and tools

- Atomic absorption spectroscopy or high frequency inductively coupled plasma.

- pH meter, with accuracy of ± 0.1 pH.

- Heat circulating tank.

- Volumetric flasks and other regular laboratory equipment.

2.3.3. Chemicals and testing substances

Only use pure chemicals and accredited standard chemicals.

- Standard chemicals of elements: arsenic (As), lead (Pb), mercury (Hg), antimony (Sb) and cadmium (Cd);

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- Hydrochloric acid, 2 mol/l solution

- And other regular laboratory chemicals required to analyze contents of heavy metal elements on the spectrometers.

2.3.4. Execution

- Use exactly 5 g of unified specimen, add 200 ml of 0.07 mol/l hydrochloric acid and shake for 1 minute.

- Examine acidity of the solution. If pH is greater than 1.5, keep shaking while adding droplets of 2 mol/h hydrochlorua acid until pH reaches or drops below 1.5. quantity up to 250 ml.

- The mixture shall be shaken continuously then left for rest for 1 hour at 37 °C ± 2 °C.

NOTE: Do not leave the mixture to light.

- Let the mixture cool and filter via blue filter paper. Collect filtered solution to determine heavy metal elements on the atomic absorption spectroscopy or high frequency inductively coupled plasma.

- Testing method must meet the required accuracy in terms of permissible limit of heavy metal elements specified in Section 3.3.4.

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Figure 1 – Illustration of filter capacity test

Figure 2 – Illustration of breathing resistance test