Should you want to add your own filter in these masks for extra protection, Mora suggests using HEPA furnace filters or HEPA vacuum cleaner bags because the HEPA filters are already designed to ...

[Ben’s] build goes above and beyond the usual craft project masks. It uses a laser-cut chipboard frame to fit three HEPA filters, originally designed for the Roomba robotic vacuum cleaner.

To bridge this gap, brands are rolling out innovative devices such as fan-powered masks, true HEPA filter masks, air purifier ...