I thought wearing an FF3 mask - correct me if I’ve got the wrong one - conferred a x42 times advantage of not getting the virus compared to an ordinary mask.
Indeed. Acccording to HSE guidance on selection of RPE, a good filtering half-mask can reduce inhalation of (X substance/thing) by a
maximum of a factor of about 40.
To do any better than that you you need to move up to a more complex system- for example a hood fed by air-line or from a belt-mounted filter pack. Which is why when providing RPE for use with carcinogens/things which cause occupational asthma where the legal duty is to not only reduce the level beyond the specified limit but also reduce it further so far as is reasonably practicable, we use air-fed systems. Most commonly see in use by persons spraying 2-pack cyanoacrylate paint (e.g. automotive respray).
Of course with a half-mask you also need a face-fit, plus be clean shaven, plus the RPE and seals need to be kept clean, filters changed as required and usually recommended no more than an hour at a time "in mask" due to the strain and discomfort of wearing a correctly fitted and effective half-mask.
That's basic stuff which any health and safety person who has worked much in fields with chemicals or dusts (silica, asbestos) should know about.
The scandal here IMO is not just the misrepresentation of face-coverings as anything other than a psychological tool of control, it's also that suitable RPE (by which I mean more comfortable airfed systems) was not introduced in healthcare settings when dealing with COVID patients. A decent air-fed hood (with a belt-filtration pack) is more comfortable, more effective at preventing inhalation of viruses and also protects the face fully, so would have been much better for at-risk NHS staff. Better one decent air-fed hood (some of which also have a face-draft to prevent overheating) than a multitude of layers of ineffectiveness.
Like the engineering professor who made the analogy that using face coverings to stop viruses is like trying to stop marbles with builders scaffold (or mosquitos with weld-mesh fence is another version I have heard), I wish medics would stick the things they understand (rather than relying on gut instinct which is basically instinctive responses from our ape-brain, very useful in some situations but not all).
If we moved away from the fixation on face coverings and unreliable testing (i.e. lateral flow tests or PCR with more than 25 cycles) and got back to proven disease diagnosis and tracking we'd find the pandemic was basically over as the thing that DOES work is the vaccine. No, it won't stop you catching the disease but it generally will stop you getting proper ill or dying from it.
TPO