> >>> One Amazon review says that it does not stop glasses from fogging. I
>>> would
>>> have thought that continuous air flow would prevent that. What's your
>>> experience?
>>>
>>> Foggy glasses are getting to be a real problem for me.
>>
>> The top edge of the mask must be "fitted" to the contour of your face.
>> This is usually accomplished with a semi-rigid metallic strip along the
>> top edge (though most folks are ignorant of how to fit it).
>>
>> In a medical environment, an adhesive layer would be in place to
>> seal that gap (cuz your face's contours don't fit the "stretched"
>> mask's shape).
>>
>> You should be exhaling through the fabric of the mask, not out the
>> over-the-ears surgical masks don't fit anywhere snug enough.
>>
>> Vented N95 masks make this easier -- and are *ineffective* for the
>> current motivation for masking (medical facilities, here, will
>> not allow you into the building wearing such a vented mask)
>>
>> [But, they're good if you're wearing one to spray paint an item!]
>
> If you had a child working on dental patients, would you want one of
> these to protect your _child from_ all the patients or
>
> a non positive air flow unit to protect the _patients from your child_?
>
If you've got a dental clinic open for non emergency work during a respiratiory tract pandemic and child labour you've aready got worse ethical problems.