if you go to a safty work clothing shop ask to see a full face mask for dust they will show them to you,you will want filters to stop dust to 5 microns,there are various makes,it shows you some on the link on the very first post.
I have never used an air cap but 9yrs ago i used to wear a very similar industrial mask which was for working in asbestos factory just down the road from me it was just the same air blower everything and a cape that went over your head and down your back didnt work for me had to get rid of birds.Had double lung transplant 18 months ago, had birds back 16mths use rubber mask gloves wide brimmed hat had no problems at all. Steve
Im afraid i wouldnt wear the air cap in the link given if you look at the picture of someone wearing it in the loft you can look through visor at front and see his ear and nestboxes behind dosnt fit to his head well wouldnt keep much dust out. I use the rubber facemask and buy new filters once a fortnight,find them brilliant only problem condensation but you learn to cough and it blows it out of mask.
I know how you feel i payed a lot of money for a hen he was paired to before ive not been able to use her. im still interested though,how much you want mick. I didnt pester you at time as you had said you problems.My problem is wife letting me spend more money
I bought a pair of catreese of wr black in 1978 they were a load of garbage just like streeters and in same condition, only thing they were fit for was polishing the dustbin which they did about 10 mins after i calmed down.