One topic we have not yet delved deeply enough into is which filter is the best to put between your mouthguard. We just received the question from a customer through the chat and thought: we can do some research on this! And it turns out: you can't just use any type of material!

At the bottom of this article are some links to the sources we used.

1. You must use a hoover bag that does not contain fibres! Because if you cut into it, these fibres come loose and you breathe them in. Not cool.
2. An alternative is simply to use kitchen paper. It contains no harmful fibres and is also cheap. In addition, you already have two or three layers of cotton in your mouth mask - and you still need to be able to breathe through it.
3. If you want to use a slightly finer filter, you will need to use the right kind of dust bag. Below is a list of bags that we think are suitable, based on their description. Note: it is always a good idea to check if this is the case.

Vacuum cleaner bag

To be clear, where we have also previously stated that it is best to use a HEPA vacuum cleaner bag, it is not! HEPA is primarily a term used for filters, and these are far too thick to put in a mouthpiece. Also, bags that do have the label "HEPA" seem to be made with microfiber (and therefore fiberglass?).

According to a video by SuperStitchSewing is The Miele U Bag is a good hoover bag to use. 99.9% filtration and no glass fibre. However, it is not cheap, see for example:https://www.amazon.nl/Miele-effici%C3%ABntie-stoftas-tellen-luchtfilters/dp/B00UTFZ9SE/

The following bag is also recommended in the comments: https://www.bol.com/nl/p/miele-hyclean-3d-efficiency-gn-stofzuigerzakken-4-stuks/9200000014961456/.

We cannot find out what material this bag is made of.

Furthermore, we have not yet been able to find a recommended type of hoover bag. We will investigate further and post updates here. Do you have a tip or know about it? Please let us know so that we can keep the information we provide here as accurate as possible.

Further deepening

A very popular video on Youtube by Dr. Ryan Southworth does use HEPA hoover bags. However, we still think that it is not wise to use them, see an article by ABC News:

https://abcnews.go.com/Health/scarves-hepa-filters-kind-face-covering-best-bet/story?id=70058603

This article contains another link to a study funded by the Dutch Ministry of Health

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2440799/.

The conclusion is this:

"Any type of general mask use is likely to decrease viral exposure and infection risk on a population level, in spite of imperfect fit and imperfect adherence, personal respirators providing most protection. Masks worn by patients may not offer as great a degree of protection against aerosol transmission."

Conclusion (provisional)

We haven't quite made up our minds yet either. But for now it seems wise to stay away from HEPA hoover bags, because of possible glass fibre particles that you might inhale. Again: do you know more? Please let us know!