My recommendation is going to echo what a lot of other folks have said here.
We were in person last year. Any time the lab had a potentially volatile compound in use we provided disposable masks for the students to use. They were deployed by their work area, so students would enter the lab with their personal masks, switch at their stations to the disposable mask, and then swap back at the end of lab. Of course we encouraged hand washing with any mask change, and the students have complimented the hand soaps I provide in lab. We opted for the general three ply disposable masks and not the flame resistant ones. Open flames are rarely used in our lab and we felt the risk was acceptable.
We had no instances of in lab transmission of covid, so I feel that this was a good decision. It was also great to have extra masks on hand for when someone forgot theirs, someone dirtied theirs (if you have sneezed into a mask you'll totally understand!), a vendor arrived unmasked, or if folks wanted a fresh one. I kept the rule of if you want one you can have one and it worked out well.
We also purchased a couple of Terracycle mask recycling boxes and encouraged students to break their mask ear strings just in case as well to prevent potential harm to wildlife should the mask end up somewhere outside of the box. We got ours through Fisher, I'm sure other retailers are available. The folks at Fisher shipped our first box with no return address label (and this is really what you are buying) and they were able to send me a return label to affix on. Just something to look out for if you haven't used Terracycle in the past.
Overall the combo worked well and I'm happy with how things went in lab last year.