The statement from Natural News seems extreme, but the key message holds true: “If it’s not air-tight, it’s not right!”
The catch is that checking whether a mask is actually air-tight turns out to be far harder than it sounds — even for trained professionals.
In 2005, a team at Prince of Wales Hospital in Hong Kong (Derrick, Chan, Gomersall and Lui) published exactly this finding in the Journal of Hospital Infection. They reviewed a hospital mask-fitting programme in which staff were fitted with two N95 masks and one N100 mask, then compared each person’s user seal check against a formal PortaCount fit test. The results were sobering: the conventional user seal check wrongly passed a badly fitting mask 18–31% of the time, and wrongly failed a well-fitting one 21–40% of the time. The authors concluded that the user seal check should not be relied on as a substitute for a real fit test.
It’s worth understanding that result correctly. The seal check they tested is the standard subjective one — you breathe in and out and try to feel for leaks around the edges of an opaque disposable mask. The problem is you can’t see the seal; you’re inferring it from sensation, and the study shows that inference is wrong a large fraction of the time. The filter can be doing its job perfectly while air quietly bypasses it through a gap you never noticed.
This is the case for making a seal something you see rather than feel — and it’s where the Totobobo mask works differently from a standard respirator. Because the mask is transparent, you check the seal with your eyes instead of your fingertips. If you need a little help, wet a piece of cotton wool and moisten your skin first — the moment the mask touches it, the semi-transparent areas turn completely clear, confirming contact. The seal is complete when that clear line forms a continuous loop around your mouth and nose. It sounds fiddly written out, but in practice it’s quick and intuitive.
That 2005 Hong Kong study was really the starting point for this whole question. The research since then has gone much further — into how ordinary people, not just fit-tested professionals, can actually reach a reliable seal. Why respirator fit matters: the independent research behind Totobobo gathers the studies that came after it. (Tellingly, one of the 2005 authors, Gomersall, also took part in the later Hong Kong fit research.)
Find out more detail on the Totobobo visual seal check.