The surgical masks that are often pictured in the media have very little value as a protective measure.
They primarily reduce the amount to which any virus is expelled by a person, rather than preventing exposure from another person.
The most effective widely face mask is the FFP3 (filtering facepiece respirator level 3), which is the same standard used where the presence of asbestos is suspected.
This will not eliminate exposure to the virus, but reduces the exposure level by up to six times compared to a surgical mask.
There have been many advertisements, particularly on social media, for N95 masks. This is an American standard that is only equivalent to UK FFP2.
The N95 mask is only tested against dry contaminants, whilst FFP3 is tested against wet aerosols. As such the N95 mask is less effective, and FFP3 should be supplied where face masks are required. The N95 mask is however preferable to surgical masks or no mask at all.
Any mask supplied must have a CE certification mark, which indicates conformity with EU health, safety and environmental protection standards.
All masks must be personal issue only – they must not be shared between workers.
To be effective the mask must fit properly, with a tight seal around the nose and mouth. Most suppliers sell fit-testing kits.
Fitting is critical as gaps around the bridge of the nose and under the chin allow air to leak in, defeating the filtration.
Guidance on face fitting is available from the HSE. The British Safety Industry Federation (BSIF) can provide detailed guidance where large scale fitting is required. The standard test involves wearing the mask, placing a plastic hood around the head and spraying saccharine solution inside it. If the sweet flavour can be tasted then the mask is not fitting tightly enough.
Where members are dealing with people who are confirmed to be infected (i.e. to provide care), then the previous advice from Public Health England still applies, and the following PPE is appropriate:
• Long-sleeved fluid repellent disposable gown;
• Long, tight-fitting gloves;
• FFP3 respirator, fit-tested;
• Eye protection – either single-use goggles or full-face visors.
Note: for most job roles, a face mask is not needed, and wearing one could increase the risk of exposure to the virus due to the wearer touching their face more often than usual.