1- Classification of respiratory masks
By increasing of airborne pollutants and particulate matter, as well as the spread
of infectious diseases such as influenza and corona virus (COVID 19), The use of
respiratory masks to prevent these pathogens from entering the airways has become
a necessity. Respiratory masks fall into the category of personal protective equipment,
which have different types in terms of application and features. The most common
of these respiratory masks are medical masks (surgery), N95 and FFP series masks.
2- Types of respiratory masks
3layers respiratory masks This type of mask is mainly used to prevent the spread
of infections or contaminations from the user to others and the environment. And
it is mainly in two types, stretched and bandages. Three-layer with bandages are
often used in surgery rooms. Due to the fact that these masks are not fully capped,
they must be used carefully and sufficiently, because it is possible for air or
contaminants to pass through the sides of the mask. These masks are designed to
trap large particles and secretions.
3- Approved Standards of respiratory masks
The two international approved standards of respiratory masks are the American NIOSH
standard and the European EN149:2001 standard. According to international standards,
Table 1 lists two important characteristics of respiratory masks, filtration efficiency
or particle trapping and pressure drop (breathability).