What is the difference between KN95 & FFP2?
The filter performance of the Chinese standard KN95, is 95% and thus slightly higher than the European FFP2 standard (94%). The leakage tolerance is identical in both standards.
The Chinese GB2626-2006 does NOT require the European standard to filter oily particles as well as oil-containing particles. The filter performance of the filters according to standard GB2626-2006 is therefore not tested for oil-containing aerosols and therefore not verified yet.
However, a requirement for filtering oily particles (kerosene mist) is not apparent for the current application requirement (SARS-CoV-2).
The masks of the test standards FFP2 (EN 149-2001) and KN95 (GB 2626-2006) are comparable for the present case (SARS-CoV-2). The aerosol in question (SARS-CoV-2)
is not oil-bound.
Medical mouth and nose protection (e.g. surgical masks):
Medical mouth-nose-protection, serves mainly for the foreign protection. It protects the person opposite from the exposure, possibly infectious drops, of the person wearing mouth protection.
The Medical Mouth & Nose Protector, is mainly used to prevent droplets from the patient's breath from entering an open wound of the patient.
Since the wearer's breathing air is primarily sucked in past the edges of the mask, mouth-nose protection for the wearer is theoretically not very effective
against pathogen-containing droplets and aerosols. However, they can protect the mouth and nose area of the wearer from direct contact with larger droplets from the opposite party. As well as before pathogen transmission through direct contact with the hands.
However, a previous laboratory study on dummies had shown that surgical face masks are better than their reputation when the masks are applied to the skin without any gaps:
Viruses were retained in up to 94.5% in a test series (see Clinical Infectious Diseases 2012, Volume 54, pages: 1569-77).
The masks, however, can only be used once.
Filtering half masks:
Filtering half-masks (FFP) are personal protective equipment (PPE) items within the scope of occupational safety and have the purpose of protecting the wearer from particles, droplets and aerosols. A distinction is made between masks with and without valves.
Masks without a valve filter both the inhaled and exhaled air and therefore offer both self-protection and protection against foreign bodies.
Masks with a valve, on the other hand, only filter the inhaled air and are therefore not designed to provide protection against foreign bodies.
In the case of breathing masks, a distinction is made between different standards. The standards of the norms can be seen in the following table.
The FFP2 standard means that the mask can filter more than 94% of the 0.3 micron particles in the inhaled air. When correctly fitted
filters about 99.8% of viruses from the air.
Mouth and nose masks:
Wearing the mouth-nose-cover can be an additional element to reduce the speed of COVID-19 propagation in the population - but only if
continue to keep a distance (at least 1.5 meters) from other people, cough and sneeze rules and good hand hygiene.
By covering the mouth and nose, infectious droplets that are emitted when speaking, coughing or sneezing can be intercepted. The risk of coughing up another person,
Sneezing or speaking can be reduced in this way (protection against foreign bodies). Such a protective effect has not yet been empirically proven, but it seems plausible.
Wearing a mouth-nose-cover in public life can help to slow down the spread of COVID-19 in the population and protect risk groups from infections
to protect. This applies in particular to situations in which several people meet in closed rooms and stay there longer (e.g. workplace) or the distance
of at least 1.5 m to other people cannot be maintained (e.g. in stores, on public transport) The prerequisite for this is that enough people have a mouth
Wear nose-covering and handle the mouth-nose-covering correctly: the covering must be worn tightly over mouth and nose and in case of moisture
must not be changed; it must not be plucked (not even unconsciously) while being worn, nor must it be worn around the neck.
source: Robert Koch Institut, Ist das Tragen einer Mund-Nasen-Bedeckung in der Öffentlichkeit zum Schutz vor SARS-CoV-2 sinnvoll, 19.04.2020.
Half mask made of silicone or rubber:
This type of mask covers mouth and nose, but in the ideal case it fits the body so that no fine dust particles enter the respiratory flow.
Unlike simple dust filters, disposing of the mask after use is too cost-intensive and a waste of raw materials. Therefore, these breathing masks contain external
filters are used, which can be replaced after each use. In normal use, e.g. when painting metal objects, filters are usually used that consist of several
layers of fine textile fibers or activated carbon.
Most of the unwanted molecules are filtered in the fine pores of the filter. These half-masks are recommended for very fine loads, since the filtered out substances are
higher concentrations and for a longer period of time can lead to negative consequences for physical health.
Complete protection - full face masks:
If one has contact with irritating substances that affect the mucous membranes, a pure half mask is no longer sufficient.
In this case, a protective mask is used that covers the mouth/nose area as well as the eyes. This prevents irritation of the eyes.
In the case of ABC (Atomic, Biological, Chemical) filters, the first layer consists of a fiberglass fabric that filters out suspended particles.
The second layer is usually made of activated carbon, which filters chemical compounds. Depending on concentration and time, the protective effect cannot be determined exactly. It follows from this that do not stay in the danger zone longer than absolutely necessary.