Particulate respirators (FFP1-3) with valve in hospital setting: yes or no? ..inside the operating rooms? ...and outside of hospital in the pandemic state?
THANK YOU (!) very much for posting this question here on the EORNA forum.
On the market, you can find two types of masks.
First we have the Surgical Masks which were initially developed by Jan Mickulicz Radecki (a surgeon from Poland) around 1870. These masks were (and actually still are) intended to be used to PROTECT THE PATIENT as well as the sterile, aseptic environment against contaminated particles in the exhaled air from the person who is wearing the mask.
The second type of masks we see on the market are the (now, under the COVID-19 challenge well known) Respiratory Protective Devices.
The FIRST INTENDED use of a Respiratory Protective Device (in short "respirator") is to PROTERCT the person WHO IS WEARING the mask.
In some situation however, not only the wearer but also the environment eg. the people (like patients) in that environment have tobe protected.
Depending on the DESIGN of a respirator, the device can protect ONLY the wearer or BOTH the wearer as well as the environment.
Because of the fact that a surgical mask has a very poor fit (some would call it "seal") between the mask and the facial skin of the wearer it will NOT protect the wearer against aerosols. In the very best case and under circumstances it can give some protection against SPLASHES. SPLASH protection SHOULD NOT be confused with protection against aerosols and the certain level of SPLASH protection can only be claimed if the mask is certified as a TYPE IIR mask according to EN14683.
Looking at the RESPIRATORS we know that they can ONLY work to protect the wearer if they have a very tight seal betweenb the mask and the skin of the wearer.
Due to the tight facial fit, the respirator can give a certain respiratory protection (FFP1, FFP2 or FFP3) to the wearer. Due to the tight facial seal, they do however reduce the comfort for the person who wears the mask. The reduced comfort is caused by the heat and the moist content of the exhaled air.
To reduce the effect of the warmth and moist of the exhaled air, manufacturers developed respirators with an EXHALATION valve. The exhalation valve will open when the wearer exhales, which makes that the warm air with a certain "moist-content" can evacuate easy from the "inside" of the respirator to the "outside" the environment. During the inhalation, the valve closes and air is forced to go through the filter.
In summary, so far we saw that we have two types of respirators, 1) unvalved respirators and 2) valved respirators.
Irrespective of whether the respirator is equipped with an exhalation valve or not, a valved respirator will offer the same level of protection to the wearer (FFP1, FFP2 or FFP3) as the device without an exhalation valve.
Because of the fact that the exhalation air which leaves the inside of the respirator is not passing through the filter the air coming through the valve is potentially contaminated with microorganisms from the wearer of the mask.
For that simple reason, a normal VALVED RESPIRATOR CAN NOT SERVE AS A SURGICAL MASK.
In cases in which both the healthcare worker (OR nurse) as well as the environment (and the patient) need to be protected an UNVALVED RESPIRATOR should be worn..... having written that, there is however a THIRD TYPE of respiratory protective devices on the market. This third type is the so callen "Shrouded Valve Respirator". A Shrouded Valve Respirator is a valved respirator with a piece of filter nonwoven on top of the valve. Bdecause of the "shrouded" (=covered with a nonwoven) valve, these respirators can protect both the healthcare worker as well as the patient, while maintaining the optimal comfort.
Another summary .... 
... there are basically three types of respirators: 1) valved respirators (which) can NEVER be used also as a device to protect the patient. 2) unvalved respirators which MIGHT protect both the wearer as well as the patient 3) "shrouded valve" respirators which will protect both the wearer as well as the patient.
Respiratory protective devices have to be tested according to EN149 surgical masks have to be tested in accordance with EN14683 and EVERY DEVICE for which the manufacturer claims that it can be used as both a device to protect the wearer as well as the environment and the patient, MUST be tested and CE certified in accordance with BOTH standards.
For those who are interested in reading more about how masks work and about the applicable EN standards and certifications, please follow the link below:
https://www.linkedin.com/pulse…QT6mXC%2BtAyq%2FqlA%3D%3D
For more questions and remarks, please never hesitate to contact me via email: gdriessen@mmm.com
With very best regards....
Geert Driessen
