Disposable Nonwoven Face Mask Testing

Disposable ordinary non-woven mask testing mainly conducts scientific testing and analysis on bacterial filtration efficiency, particulate filtration efficiency, breathing resistance, microbial indicators, ethylene oxide residue, and structure and dimensions, objectively assessing the product quality grade and issuing a detailed test report, providing a basis for manufacturers' quality control and downstream users' product acceptance.

Testing Items

Bacterial filtration efficiency (BFE): This is the key indicator for measuring the ability of the mask to block bacteria, usually required to be not less than 95%. The test simulates the bacteria-containing droplet aerosols produced when the wearer speaks and coughs (such as a Staphylococcus aureus suspension), and the filtration efficiency is calculated by comparing the number of colonies upstream and downstream. It is the core basis for evaluating the protective performance of disposable non-woven masks.

Particulate filtration efficiency (PFE): Used to evaluate the filtration effect of the mask on non-oily particulate matter (such as dust, pollen and aerosols). The test often uses a sodium chloride aerosol with an average particle size of about 0.3 micrometres or similar media, simulating fine particulate matter in the air. The concentration difference before and after filtration is measured by a professional particle counter, and the filtration efficiency percentage is calculated.

Breathing resistance (pressure difference): Refers to the pressure difference before and after the air flow passes through the mask sample under certain test conditions. This item is directly related to the breathing comfort of the wearer. Excessively high resistance will cause breathing difficulty, while excessively low resistance may mean that the filter material is too sparse and the protective performance is insufficient. Therefore, it is necessary to control the resistance within a safe and comfortable range while ensuring the filtration efficiency.

Microbial indicators: Refers to that the mask itself must not become a source of microbial contamination. The total bacterial colony count, total fungal colony count and specific pathogenic bacteria (such as coliform bacteria, Pseudomonas aeruginosa, Staphylococcus aureus and hemolytic streptococcus) are mainly tested. This indicator ensures that the mask is not contaminated during production, packaging and storage, and is an important hygiene and safety requirement.

Ethylene oxide residue (if applicable): For masks sterilized with ethylene oxide (EO), the residue must be tested. EO is a toxic carcinogen, and long-term exposure is harmful to health. The test uses methods such as gas chromatography to ensure that the residue is lower than the limit of the national standard (such as 10 μg/g), ensuring the safety of the wearer.

Structure and dimensions: Checks whether the appearance structure of the mask is complete and free of damage, stains and foreign matter. Its key dimensions such as the length, width, nose clip length and strap length are measured, ensuring that it conforms to the design specifications, can effectively cover the mouth and nose, and fit the face. This is the basis for ensuring the effectiveness of protection.

Flame retardancy (required for specific occasions): For masks that may come into contact with open flames or high-temperature environments (such as certain industrial and laboratory scenarios), their flame retardancy needs to be tested. The mask sample is placed under a specific flame, and its afterflame time and damaged length are observed, to prevent aggravating injuries in accidental fires.

Testing Scope

Medical surgical masks: In accordance with the YY 0469-2011 "Surgical masks" standard, full testing of BFE, PFE, breathing resistance, synthetic blood penetration, microorganisms, ethylene oxide residue and other items is required. It is mainly suitable for invasive operation environments such as clinical operating rooms and the basic protection of medical staff.

Medical protective masks: In accordance with GB 19083-2010 "Technical requirements for medical protective masks", the testing requirements are the most stringent. The core indicators include PFE (Grade 1 ≥95%, Grade 2 ≥99%, Grade 3 ≥99.97%), surface wetting resistance, synthetic blood penetration and fit, etc. It is suitable for high-risk scenarios involving contact with airborne or close-range droplet-transmitted diseases.

Daily protective masks: In accordance with GB/T 32610-2016 "Technical specification of daily protective masks", mainly for civil anti-haze, pollen and other scenarios. The core testing items include PFE, inhalation resistance, exhalation resistance, protective effect (combined filtration efficiency and leakage rate), formaldehyde content, pH value, and decomposable carcinogenic aromatic amine dyes.

Disposable medical masks: In accordance with the YY/T 0969-2013 "Disposable medical masks" standard, belonging to ordinary medical masks. The testing items are relatively basic, focusing on BFE (≥95%), breathing resistance, microbial indicators, ethylene oxide residue and so on. It is suitable for general protection in ordinary medical environments.

Masks exported to the EU: If used as medical devices, they need to comply with the EU Medical Device Regulation (MDR) and the EN 14683:2019+AC:2019 standard. The testing items are similar to YY 0469, but some test methods and judgement indicators are different, such as the aerosol particle size of the BFE test, pressure difference requirements, etc., and the relevant CE certification requirements need to be met.

Masks exported to the United States: If used as surgical masks, they need to comply with the American Society for Testing and Materials standard ASTM F2100-21. This standard divides masks into three levels: Level 1, 2 and 3. The testing items include BFE, PFE (using latex particles), resistance, synthetic blood penetration and flame retardancy, etc. It is the key to obtaining FDA 510(k) market access.

Testing Methods

Bacterial filtration efficiency (BFE) test method: With reference to Appendix B of YY 0469 or the ASTM F2101 standard. A Staphylococcus aureus bacterial suspension is used to generate an aerosol, and a six-stage Anderson sampler or equivalent equipment is used to separately collect and culture the viable bacterial particles in the aerosol before and after passing through the mask sample, and the filtration efficiency is calculated by colony counting.

Particulate filtration efficiency (PFE) test method: Common methods include the oily particle method (such as GB 2626, using DEHS aerosol) and the non-oily particle method (such as GB 19083, using sodium chloride aerosol). An aerosol generator is used to produce monodisperse or polydisperse aerosols with a specific particle size distribution, and laser particle counters are used to measure the upstream and downstream concentrations, automatically calculating the efficiency.

Breathing resistance test method: In accordance with the standard provisions, under a specific constant air flow (such as 8 L/min for YY 0469 and 85 L/min for GB 32610), a differential pressure gauge or equivalent equipment is used to measure the gas pressure difference between the two sides of the mask sample. The test needs to be carried out under standard temperature and humidity conditions, and the results are reported in pascals (Pa).

Synthetic blood penetration test method: Simulates the scenario of blood or body fluid splashing during surgery. The mask sample is fixed on a specific support device, and at a specified distance and pressure, a certain volume of synthetic blood (with a known surface tension) is sprayed toward the outer surface of the mask. Whether liquid penetrates the inner surface is observed, to evaluate its penetration resistance.

Microbiological test method: In accordance with the "Pharmacopoeia of the People's Republic of China" or the GB 15979 standard. A mask sample of a certain area is taken, buffer solution is added for full elution, and the eluate is inoculated on nutrient agar medium (for bacteria) and Sabouraud dextrose agar medium (for fungi). After culturing under the specified conditions, counting is carried out, and specific pathogenic bacteria are detected.

Ethylene oxide residue test method: Mainly uses the headspace gas chromatography method. The mask sample is cut into pieces and placed in a headspace vial, equilibrated at a constant temperature so that the residual EO fully volatilizes into the upper space (headspace) of the vial, and then quantitative analysis is carried out with a gas chromatograph (usually equipped with a flame ionization detector, FID).

Testing Standards

Domestic Standards:

1. GB 19083-2010, Technical requirements for medical protective masks

2. GB/T 32610-2016, Technical specification of daily protective masks

3. GB 18401-2010, National general safety technical code for textile products

4. GB/T 3920-2024, Textiles — Tests for colour fastness — Colour fastness to rubbing

International Standards:

1. ISO 13934-1, Textiles — Tensile properties of fabrics — Part 1: Determination of maximum force and elongation at maximum force using the strip method

2. ISO 105, Textiles — Tests for colour fastness

Note: The applicable standard can be selected according to the product use and customer trade requirements; standards agreed in the contract take precedence over general standards.

Testing Instruments and Equipment

Filtration efficiency tester: The core equipment, integrating an aerosol generator (such as sodium chloride, DEHS and latex sphere generators), a neutralizer, a particle counter, a flow control system and test fixtures. It can automatically carry out PFE/BFE tests, monitor and record the upstream and downstream particle concentrations in real time, and precisely calculate the filtration efficiency, such as models like the TSI 8130A.

Breathing resistance tester: Mainly composed of a precision flow meter, a pressure sensor, a test cavity (head form or flat fixture) and a flow control unit. It can precisely control and stabilize the test air flow, measure the pressure difference between the two sides of the mask with high precision, and some equipment can be compatible with multiple flow standards, realizing one-key testing.

Synthetic blood penetration tester: Including a blood injection device (usually a syringe pump or pneumatic drive), a standard nozzle, a sample fixing fixture, a pressure gauge and a distance scale. It can precisely control the injection speed, volume and pressure, simulate blood splashes of different intensities, and be used to evaluate the liquid blocking ability of the mask.

Microbiological testing related equipment: Mainly including aseptic operation benches (clean benches), high-pressure steam sterilizers, constant temperature incubators (37 ℃ for bacteria and 20-25 ℃ for fungi), homogenizers or vortex mixers, and colony counters. These equipment together ensure the aseptic operation and accurate culture and counting of the microbiological testing process.

Gas chromatograph (GC): The key analytical instrument for ethylene oxide residue testing. It is equipped with an automatic headspace sampler, a capillary chromatographic column and an FID detector. By comparing the retention time and peak area of the chromatographic peaks of the sample and the standard substance, qualitative and quantitative analysis is carried out, with high sensitivity and accurate and reliable results.

Flame retardancy tester: Usually a vertical burning tester. It includes a standard burner, a sample fixing frame, and automatic ignition and timing devices. It can precisely control the flame height and application time, automatically record the afterflame time and afterglow time of the sample, and measure the damaged length, to evaluate the flame retardant characteristics of the material.

Digital force gauge and tensile testing machine: Used to test the connection firmness of the mask straps. The force gauge can be used to measure the force required for breaking at the connection point between the strap and the mask body; the tensile testing machine can carry out more complex tensile and peeling strength tests, evaluating the mechanical durability of the overall structure of the mask.