Posted By M Dolman Our company restaurant manager has notified me that her staff are using their disposable face masks 2-3 times before throwing them away. They use the masks when cleaning the oven which takes approx 10 minutes. The oven cleaner contains sodium hydroxide. Am I right in stopping this practice or is re-use of disposable masks acceptable? Any comments would be appreciated. Thanks.

Posted By John Webster In general terms, I agree with Martin, although in this particular case I would tend to be more concerned about hygiene. I would also congratulate your kitchen staff on actually using some PPE for this job - so often ignored. I trust they have long PVC gloves and eye protection as well? The problem with oven cleaners is that they produce an aerosol mist of sodium hydroxide (caustic soda) which is corrosive to skin and mucous membranes, eyes etc. The mask is therefore required to intercept a mist rather than a vapour. The mist will react with carbon dioxide in the moist exhaled breath and in the atmosphere to produce sodium carbonate (bicarbonate of soda) so the reused mask will now have a coating of the latter. In practical terms, given the application and the period of use, I would not expect there to be a breakthrough of harmful material after 2 to 3 uses. HOWEVER, re-use of disposables is poor practice as it leads to the belief that any disposable item can be used over and over again. Yet there is no provision in disposable design for cleaning/sanitisation. Even if the same person is re-using the mask (I HOPE it is the same person) bacteria and mould spores can build up and then multiply in storage. Placing the slightly damp mask in a plastic bag (to avoid soiling in storage) in a warm locker room will ensure the bugs have optimum breeding conditions!! So up the budget for masks. They don't cost that much! John