The world is facing a shortage of masks and other protective equipment against Coronavirus, the head of the World Health Organization warned on February 7th. Surgical masks are especially in demand. But are they really effective? What kind of masks actually protect against Covid-19? Also, a new type of protective mask called “barrier mask” has appeared. Read to know more about it.
Hicham Dhouibi, DirectIndustry technical expert, contributed to this article.
Since the outbreak, people in China and in the rest of the world have rushed to their local pharmacies to get surgical masks. But there are different types of masks on the market, and not all of them are really effective against this virus. So, which masks actually offer protection?
Surgical Masks vs. Respirators
There are two different types of masks: surgical masks and respirators.
A surgical mask is a disposable medical device that can be bought in pharmacy and that protects against infectious agents transmitted by “droplets.” These droplets can be droplets of saliva or secretions from the upper respiratory tract when the wearer exhales.
If worn by the caregiver, the surgical mask protects the patient and his or her environment (air, surfaces, equipment, surgical site). If worn by a contagious patient, it prevents the patient from contaminating his or her surroundings and environment. A surgical mask can also protect the wearer from the risk of splashes of biological fluids. In this case, the surgical mask must have a waterproof layer. It can also be equipped with a visor to protect the eyes. These masks are single-use devices and should not be worn for more than 3 to 8 hours.
>>> However, despite the panic buying frenzy, a surgical mask does not protect against “airborne” infectious agents so it will not prevent the wearer from being potentially contaminated by a virus such as Coronavirus.
A respirator is personal protective equipment that prevents the wearer from inhaling aerosols (dust, smoke, mist) as well as vapors or gases (disinfectants, anesthetic gases) that are health hazards. It also protects those who wear them from inhaling “droplets” of infectious agents.
Respirators can be insulating and filtering. Filtering respirators consist of a facepiece and a filtering device. Depending on the type of filter, the mask will either be effective only against particles, only against certain gases and vapors, or against particles, gases and vapors. Filtering respirators can sometimes also be equipped with an exhalation valve to improve user comfort. The valve prevents condensation inside the mask, misting on the glasses and helps the user breathe in and out easily. Respirators can be disposable or reusable. In the second case, it is possible to replace the filter when it is full.
>>> Unavailable in pharmacy, respirators protect the wearer from airborne infectious agents i.e. against contamination by a virus such as Coronavirus, SARS, H1N1, etc. They are therefore the masks that actually protect against Coronavirus.
How to Choose the Right Mask?
Even if a surgical mask does not prevent the wearer from being potentially contaminated by Coronavirus, a contagious patient should wear a surgical mask as soon as contagion is suspected. For caregivers, it is necessary to wear a respirator. But how to choose the right surgical mask and the right respirator? Each of these two types of masks is subject to different standards and regulations depending on the country or geographical area.
Surgical masks are tested in the direction of exhalation (from inside to outside). The tests take into account the efficiency of bacterial filtration.
>>> In Europe, they must comply with the European standard EN 14683, which has 3 levels of bacterial filtration efficiency (BFE1, BFE2, Type R).
>>> In the United States, they must respect ASTM standards which have three levels of protection (from low risk of exposure to fluids to high risk of exposure to fluids).
Respirators are tested in the direction of inspiration (from outside to inside). The tests take into account the efficiency of the filter and leakage to the face.
>>> In Europe, they must meet the European standard EN 149: 2001 which has three classes of disposable particulate respirators (FFP1, FFP2 and FFP3).
>> FFP1 refers to the least filtering of the three masks with an aerosol filtration of at least 80% and leakage to the inside of maximum 22%. This mask is mainly used as a dust mask (home renovations and various types of work).
>> FFP2 masks have a minimum of 94% filtration percentage and maximum 8% leakage to the inside. They are mainly used in construction, agriculture, and by healthcare professionals against influenza viruses.
>> FFP3 masks are the most filtering mask of the FFPs. With a minimum filtration percentage of 99% and maximum 2% leakage to the inside, they protect against very fine particles such as asbestos.
>>> In the United States, respirators must meet NIOSH (National Institute for Occupational Safety and Health) standards. Within this standard, there are several classes of respirators depending on the degree of oil resistance:
>> Class N: no oil resistance. A distinction is made between N95, N99 and N100. The number after the letter indicates the percentage of filtration of suspended particles.
>> Class R: mask resistant to oil for up to eight hours. Here again, a distinction is made between R95, R99 and R100.
>> Class P: a completely oil-resistant mask. There are also P95, P99 and P100.
>>> Respirators of class FFP2 or FFP3 (EU standards) and of class N95 (US standards) are the ones offering maximum filtration of particles and aerosols. Caregivers should wear them when caring for a patient who is infected or suspected of being so.
The New Barrier Mask
The shortage of FFP2 and surgical masks has fueled an increase in patterns and tutorials for making protective masks. A new type of protective mask has recently appeared and has been approved by certification organization AFNOR. The “barrier mask” is meant to be worn by healthy people. AFNOR has produced a reference document with the requirements to be satisfied when making these new barrier masks. This AFNOR Spec – Barrier masks document can be downloaded online free of charge.
The requirements for barrier masks are less ambitious than those for FFP2 and surgical masks, which should be reserved for healthcare professionals and other people at risk of exposure. Barrier masks meet a set of criteria endorsed by 150 experts and are aimed at providing all healthy people with further protection, in addition to good hygiene practices and social distancing. Textile and plastics companies can use the document to mass-produce these masks. The document’s appendix includes a list of laboratories (list to be complemented by the AFNOR website) for companies wishing to test their prototypes before going ahead with mass production. The document is also intended to offer guidance to all those with the necessary materials and craftsmanship to make masks by themselves. It contains a number of diagrams, as well as ready-to-use patterns.
Since it was made available in French on 27 March 2020, the barrier mask model has been downloaded nearly 100,000 times, by a variety of profiles: manufacturers capable of launching mass production, craftsmen, private individuals who are adept at “Do it yourself”, or local authorities for their staff.
The Covid-19 pandemic being worldwide, the model of barrier mask is now available in several languages. Spain, which has been hit hard by the virus, now has its version in Castilian. Versions in German, Russian and Chinese are also expected in the coming days. At the same time, the document has been circulated within the International Organization for Standardization (ISO); international NGOs are also analyzing the document in order to include it in their datasheets, particularly in the framework of their actions in favor of developing countries.
Model in English available here
Model in French available here
Model in Spanish available here