Posted on 1st Feb 2020 @ 8:02 PM

Some of our medical connections have been advertising "medical masks" to protect against Coronavirus. At best, these masks are likely to simply limit viral transmission. They are designed and worn, essentially to limit transmission TO THE PATIENT, not from him or her. Anyone who is concerned MUST have masks tested to the minimum performance represented in EN149, or better.

I replied to those promoting inadequate (better than nothing) masks as follows; explaining the rational and the law in EU countries (and mirrored in the USA, Canada and Australia -

"Medical Grade" face masks offer very little protection from viral particles or even from much larger bacteria. They are designed simply to discourage cross contamination and do not provide anywhere near to reliable protection from aerosol borne threats, like viruses.
Proper respirators are needed for effective protection, such as those marked and approved to the following standards - as required under PPE Regulations.

and which say: (HSE HSG53)
"RPE used at work must be manufactured in accordance with the Personal Protective Equipment Regulations 2002.4 In practice, this means you need to use CE-marked equipment. The CE mark on RPE tells you that the equipment has met the minimum legal requirements for its design. 34 This marking appears as the letters ‘CE’ and a four-digit code that identifies the body responsible for checking manufacturing quality (see Figure 3). 35 CE marking does not indicate that an RPE device is automatically adequate and suitable for use in your workplace. It is your responsibility to select the correct RPE to meet your specific requirements."

....and from the HSE web site: "To help ensure you are protected, all respirators provided for use at work must be CE marked to show that the design has been tested to a recognised standard. They must also be marked with that standard, which for disposable respirators is EN 149: 2001. Additional markings, such as FFP1, FFP2 or FFP3, indicate the protection level that you can get if the respirator is a good fit and you use it correctly. The higher the number, the better the protection. FFP1, FFP2 and FFP3 respirators can reduce the amount of dust you breathe by factors of 4, 10 and 20 respectively. An FFP3 respirator is advisable if you are exposed to high levels of grain dust or mould spores."...
and....
"Some retailers also sell products known as nuisance dust masks or comfort masks that look like dust respirators but are not marked with CE or with any standard. They often have only one head strap. These are not intended for use when a respirator should be worn. You should never use a nuisance dust mask instead of an approved respirator when working with (biological agents) grain dust or mouldy hay, straw, grain or other material that could cause occupational asthma or farmer’s lung. Packaging for these masks might be labelled, ‘This product does not provide respiratory protection’, or something similar." These are often sold as medical masks, for which there are no agreed test protocol.

The medical profession is alert to the dangers of inadequate protection and several bulletins have been made public - for example:
DO medical masks work?
>https://www.medpagetoday.com/infecti…/infectioncontrol/16278
> Unmasking the Surgical Mask: Does It Really Work? | Medpage Today
www.medpagetoday.com

> For a century, the surgical mask has been the symbol of a safe and sanitary medical environment. The problem is that researchers don't really know if that's true.
Some words of support for the simple mask, which qualifies the cross contamination rates..
https://www.nytimes.com/…/face-masks-work-healthy-colds-flu…

Back to the HSE research on the limitations of "medical masks" ... You may read it all but the summary paragraph says
> "This study focussed on the effectiveness of surgical masks against a range of airborne particles. Using separate tests to measure levels of inert particles and live aerosolized influenza virus, our findings show that surgical masks can provide around a 6-fold reduction in exposure. Live viruses were detected in the air behind all surgical masks tested.
By contrast, properly fitted respirators could provide at least a 100-fold reduction. "
(And there are large differences in the viral transmission rates between the designs tested.)
>https://www.hse.gov.uk/research/rrpdf/rr619.pdf

I should add that BS EN 14683:2019 has been introduced under the provisions for (Key words) the construction, design, performance requirements and test methods for medical face masks intended to limit the transmission of infective agents from staff to patients during surgical procedures and other medical settings with similar requirements. NOTE: INTENDED TO "LIMIT" THE TRANSMISSION of infective agents - not to prevent transmission to the staff, carers or anyone in the vicinity. The chart here describes the very poor standard of protection offered in the instances of so called "medical masks"

More information on grades of respiratory protection:
http://www.heliosuk.com/products.php…