Non-woven fabric surgical masks (with randomly oriented fibers) work (to some extent) as source control. They help reduce the risk that you will infect others,

Non-woven fabric surgical masks (with randomly oriented fibers) work (to some extent) as source control. They help reduce the risk that you will infect others, not that others will infect you. Properly fitted and worn FFP3 masks reduce the risk of the wearer becoming infected, but they are not a panacea, and "properly fitted and worn" is harder than you think. Cloth masks may provide a tiny bit of source control, but not nearly as much as a surgical mask, and they may even make things worse as they can cause large droplets to split into smaller droplets which are harder to filter and remain suspended in the air longer.