FACE MASKS FOR ISOLATION, INCLUDING PROTECTIVE MASKS AGAINST VIRAL INFECTIONS SUCH AS CORONA VIRUS AND SWINE FLU (BIRD FLU, H1N1) AND OTHER VIRAL INFECTIONSThere are many questions about which face masks are actually effective in protecting against pandemic viral infections such as the coronavirus, avian influenza, and other viral infections. They also ask what these types of masks look like (for example, what is meant by a duckbill mask or a surgical mask ).
The very best face masks also offer protection against droplet transmission (Fluid Shield).
Furthermore, it's important to know whether fine particles are also blocked by the filter. The quality designation FFP1, FFP2, or FFP3 is often used. An FFP2 face mask is good. Other duckbill-type face masks also offer good protection, and standard surgical face masks also offer reasonable to adequate protection.
Below are some examples of different face masks. Institutions must decide for themselves which types and manufacturers they will use. Highly protective masks (FFP2) are much more expensive than standard surgical masks and are also uncomfortable (they don't seal).
duckbill mask (Kimberley Clark white 62126)FFP2 quality mouth mask (maximum protection against viral infections).
duckbill mask orange (Kimberley Clark 47707)Good quality for normal protection against transmission of viral infections.
regular surgical face mask blue (Kimberley Clark 47500)Reasonable protection of personnel against transmission of viral infections.
regular surgical face mask green (Kimberley Clark 48105)Reasonable protection of personnel against transmission of viral infections.
regular surgical mask yellow (Kimberly Clark 47117)Reasonable protection of personnel against transmission of viral infections.
BACKGROUND INFORMATION ON FACE MASKS STANDARDSSource/Author: Thea Daha (Hygienist, Infection Prevention Working Group)
Until now, two types of face masks are used in healthcare:
- the surgical mask
- a special mask used during the treatment of tuberculosis patients
(see examples above, the duckbill mask).
The surgical mask is used in the operating room, among other places, and serves a dual purpose: on the one hand, it protects the patient from particles released during speech, sneezing, and coughing by staff, and on the other hand, it protects staff from blood splatter and splashes of bodily fluids from the patient.
Surgical masks are tested according to the Greene & Vesley test method to determine the bacteriological filter efficiency (BFE). A box containing plates (culture media) is used. The subject wears or does not wear a mask, and the word "tjie" is pronounced through a hole in the box. By examining any contaminated plates in the box, the filter efficiency is determined.
This test evaluates how well a mask or surgical mask can help prevent bacteria exhaled by the wearer from entering the environment. The particle size in the BFE tests is considered "large" (1-5 microns). A mask used during the care of a patient with tuberculosis or suspected tuberculosis is called a "tuberculosis mask."
Hospital and institutional guidelines indicate when a surgical mask or a "TB" mask should be worn. The CDC prescribes an approved N95 mask for tuberculosis, which is a snug-fitting face mask with a filter range of up to 1 micron. There is no uniform global standard for respiratory protection, and therefore, due to this situation, we must adapt. The European-approved equivalent of the American NIOSH-approved N95 mask (42CFR84) is an EN149:2001 FFP2 mask. EN149:2001-approved masks may also be additionally tested according to the Greene & Vesly test. This information is available from the manufacturer.
European legislation and regulation 89/686/EEC
In Europe, and therefore also in the Netherlands, we are subject to European laws and regulations that impose specific requirements on respiratory protection. For example, we are familiar with European Directive 89/686/EEC for personal protective equipment (PPE). This original European Directive 89/686 has been transposed into the Dutch Working Conditions Act (Arbowet). Directive 89/686 governs the CE marking and the classification into categories. Respiratory protective equipment is classified in the most stringent category (Category 3) because it must provide protection against life-threatening risks or risks that lead to irreversible health problems, or risks whose consequences cannot be detected in time.
There are reusable masks with replaceable filters and disposable masks. In healthcare, the former are not suitable because making such masks "ready for use" again presents too many practical difficulties. Therefore, only disposable masks are used. This results in masks that comply with EN149:2001.
The EN149:2001 standard is the European standard for filtering masks and includes three important type approvals:
FFP1,
FFP2,
and FFP3.
FF stands for filtering facepiece, P stands for particle, and the number 1, 2, or 3 indicates the distinguishing feature. All three types are approved, and the edge leakage is also defined in the approval. The maximum permitted edge leakage (leakage along the edges of the mask) within the EN149:2001 standard is 2% for all types. Besides edge leakage, there is also filter leakage of the filter medium (the filtering effect of the mask material). For FFP1, this is a maximum filter leakage of 20%, for FFP2: 6%, and for FFP3: negligible (max. 1%).
The total inward leakage (TIL) (edge leakage and filter media leakage) is 22% for the FFP-1, 8% for the FFP-2, and 2% for the FFP-3.
Testing the EN149:2001 masks
EN149:2001-approved masks are tested for industrial use with liquids such as sodium chloride (NaCl) and paraffin oil. Here, the filters are tested with particles, with the difference that in industrial workplaces, concentrations and MAC values are discussed, while in healthcare we deal with other particles such as bacteria and viruses. However, with current knowledge of filter techniques and the physical properties of bacterial particles (viruses are also classified below), these filter masks function in the same way as in industrial settings. EN149:2001 tests with particles approximately 0.4-0.6 µm in size. This particle size was deliberately chosen because these are the most difficult particles to capture. The result is highly efficient filter masks.
New recommendations
: The infection prevention working group's guideline recommends a mask with a filter range of up to 1 micron and a snug fit for patients in strict isolation.
To comply with European regulations, taking into account the N95 mask recommended and approved by the CDC and WHO, we also use an FFP2 type mask for "TB." This recommendation is also given for the treatment of patients with MRSA or SARS, or those suspected of having these.
How do I recognize an approved FFP2 mask?
An approved respiratory protective mask must have the following information: EN149:2001, FFP2 class, and the CE mark with a four-digit code.
This does not mean that the surgical mask used until now will be phased out. Surgical masks also have a CE mark (however, in accordance with the medical guideline, MDD) and can be used in healthcare (for applications: see the introduction). |
