Crafting for Healthcare professionals

I don’t really sew that much, so I won’t be making masks en masse, but I do have cotton yarn and basic crochet skills, so I thought I might make these mask straps

They use buttons, and I’m wondering what I should be aiming for in the way of buttons - can plastic buttons survive an autoclave, or should I be looking for other button materials? Since they are using buttons because they’re easy, I could for instance, get metal washers and wrap them with more yarn to get the same functionality.

Also, is anyone else crafting to help others?