FAQ on Face masks production, requirements, testing and standards

Disclaimer: The information in in this page is indicative only, neither exhaustive nor extensive. It is shared free of charges for the sole purpose of helping companies in increasing their mask production capacity in the time of the COVID-19 crisis. EURATEX cannot be held responsible for the content provided, nor for the use which may be made thereof.

The specifications are set in the European Standards EN14683 (Medical masks) and EN149 (PPE masks) and can be downloaded free of charge during the COVID-19 crisis through CEN national members.
EURATEX has a daily updated list of companies offering/requesting materials or capacities.
EURATEX has online a list of testing organizations, carrying out related tests.
In Europe, medical face masks must comply with the legislation (Directive 93/42 - to be replace by Regulation 2017/745). Compliance with the requirements defined in EN 14683 is the most common way to prove compliance with the legislation. Medical masks shall have a CE-mark.
In Europe, PPE products must comply with the Regulation 2016/425. Compliance with standard EN149 (Respiratory protective devices - Filtering half masks to protect against particles - Requirements, testing, marking) is the most common way to prove compliance with the Regulation. PPE masks shall have a CE-mark followed by the number of the notified body responsible for the production follow-up.
In the case of respiratory protective devices, the standard (EN149) imposes specific design requirements. In the process towards certification, tests are done on the ready-to-use products. In the phase before certification (meaning during the product’s development), companies should first evaluate the materials. In the case of medical masks, the standard does not impose design requirements. The certification tests can be performed on the materials only, or directly onto the final product.
To speed up the testing process of Medical and PPE face masks, as a first step, it is suggested to test the materials (i.e. the fabrics) before the finished product. The tests can be prioritised in the following order: i) Air-permeability (or Pressure difference), ii) Bacterial filtration efficiency (BFE). In case the test results meet the standards requirements, the masks production can start. The following tests are: iii) Splash tests (for type IIR Medical masks only) and iv) Bioburden = microbial cleanliness test (for all masks). When testing the materials, the companies must specify the material structure and the composition, and they must clearly indicate which side of the material is the outer part (the part exposed to the external environment). A strict minimum of 10 mask-samples should be provided; 20 is recommended in order to allow retesting if needed. Respiratory protective devices should undergo full testing, according to EN149. It is recommended that first air-permeability (inhalation/exhalation test), the penetration and the exposure (also called the loading test) tests are performed on the materials or material combination. The penetration & exposure test is performed using sodium chloride and paraffin aerosols. In general, the paraffin aerosol is more challenging. If the tested material does meet the requirements, further testing can be done on the full mask.
Practice shows that textile materials of woven and knitted structure do not achieve the required Air permeability and Bacterial Filtration Efficiency tests’ thresholds, set in the relevant standards. Textile woven materials do have low air permeability. Simple knitted (folded 2-3 times) and woven material do not meet the PPE and Medical requirements, according to usual practices. Microfilament nonwoven are not suitable according to EN14683 requirements. Reusable materials are able to fulfil bacterial filtration efficiency requirements. Different materials, such as Polycotton and viscose, were tested and the results can be consulted in a list published in French. Different indications on nonwoven materials have been tested in Italy and shared by the Politecnico di Milano (in Italian).
Due to the current COVID-19 crisis, the testing period depends on capabilities, capacity and workload of each testing centre.
EURATEX lists relevant material suppliers and test laboratories. Medical masks have to meet the requirements of the Medical Device legislation and comply with standard EN 14683: Medical face masks - Requirements and test methods and shall have a CE-mark. Currently, it is not necessary to contact a notified body (which is a centre authorised to test and/or release certificates). Manufactures must be able to prove that materials/product meet the EN14683 standard requirements. Manufactures can afterwards fix the CE mark by themselves, provide the declaration and the technical product paper. Requirements to produce community masks may vary across the EU. As the legislation is not yet harmonised, companies are advised to contact their national associations for more information.
Community masks is a term referring to masks which offer a certain degree of protection filtering the air, however without compliance to standards or certifications as it the case for the PPE and Medical masks. There is currently no harmonised EU legislation on community masks but very different legal framework at national level and expect to last for the time of the COVID-19 crisis. Some EU Member States introduce new type of masks either de facto (the Government of Czech Republic requests wearing of masks outside households, including home-made masks as of 18th March 2020.  In Austria wearing face masks shall become compulsory as of April 6 according to media) or through legal provisions. In Italy, the Ministry of Health issued a communication introducing the category of “filter masks” based on the national decree D.L. 17 March 2020, n.18. In France, on 30th March the government introduces 2 new categories of masks. Category 1: Individual mask for professional use in contact with the public. Category 2: Mask with collective aim to protect the whole group wearing them. These masks must meet defined technical specifications. The authorities shares information including results or tests on companies’ prototypes (link in French). In Germany, the Federal Institute for drugs and Medical Devices has issued a note on using community masks, medical masks and FFP-masks in connection with the Covid-19-crisis.
Manufactures of Community masks (also called comfort masks) can not claim any protection. They must specify that the masks are neither Medical nor PPE type. Manufacturers are responsible for the product they place on the market. Buyers may set specifications for this type of product based on their assessment of the risks and the intended use of the mask. Some national industry associations have published information based on their national legal framework. In Italy, the national association SMI issued a recommendation (link in Italian) for producers to inform consumers and to follow the guidelines used in the standard EN 14683, notably on Materials and construction (5.1.1) general (5.2.1), Bacterial Filtration efficiency (5.2.2) and Breathability (5.2.3). In France, the Comité Stratégique de la Filière (link in French) , including the national associations UIT and UFIMH, provides information on all types of masks. In Germany, the national association “textil+mode” has published guidance (link in German) for producers on technical (e.g. choice of materials) and legal aspects when placing such masks on the market. An English translation of the guidance is expected soon on the same website.
Detailed guidelines for the perfect mask design and production do not exist. Applicable standards must be followed. However, patents website with types of masks from around the world can be look into as source of inspiration (Espacenet). Producers of patented masks websites could be used as a reference point. Further information is also shared in relation to the CODIV-19 crisis (see links in questions 9 and 13). In general, a Medical mask relies on a melt-blown layer of good quality. The structure of the mask is a SMS structure (spunbond-melt blown-spunbound) where the melt-blown layer - the actual protection - has a weight of 25 to 30 g/m2. PPE masks are mainly made with layers offering different functions. A layer provides the shape of mask while one or more layers provide the protection. The choice of materials varies, from melt-blown layers, microporous PTFE membranes, glass fibres to split film fibres or even electro-spun layers.
There are no specific finishing treatments that can be recommended. Experience shows that BFE treatment does not increase the barrier properties of materials. In order to catch small particles, some manufacturers use high strength electrical field after the melt-blown process or use specific additives during the extrusion step. Materials that are not sufficiently resistant to moisture absorption can be finished with water repellents according to some sources.
For the Medical masks 4 tests are needed, 2 are essential: BFE and air-permeability. BFE tests are performed with an aerosol with droplets of an average seize of 3µm. These droplets are loaded with bacteria to simulate the aerosol generated when a person speaks or coughs. This aerosol is sent through the masks and collected on agar inside an Anderson Impactor, which sorts the droplets according to seize. The bacteria are then grown and counted. From this the BFE is calculated. For the air-permeability an air flow of 8l/min is send through the sample and the pressure difference is measured. An equivalent test is to use the ISO9237 on a sample seize of 20 cm2 and a pressure difference of 100Pa. The flow through the sample should then be at least 139 l/m2/s. In this approach we assume that the sample exhibits a linear behaviour between flow & pressure.For FFP masks the full testing is more complex and we refer to the standard to have an overview of the test equipment. The most essential tests are aerosol test with salts particles and paraffin particles. In general, the test with paraffin is more challenging and it is recommended to perform this test in priority to have an idea about the barrier properties of the material. This test requires however specialised equipment as well as the test using salt aerosols.

Acknowledgement: EURATEX thanks and acknowledges the ESF federation (www.eu-esf.org) and the Centexbel laboratory (www.centexbel.be) for the contributions provided and the kind availability in sharing know-how.