Not a lot. If the laser module somehow broke off and pointed somewhere it would be bad, though it is not a very coherent beam actually so it wouldn't be horrible if you were watching and shut it off quickly (I did get laser safety glasses but they are cheap ones).
I did have lunch with a laser safety engineer about 20 years ago who scared the shit out of me talking about problems with blue lasers. That deterred me from ever playing with for example those big handheld laser pointers you can buy. But this module is about 30mm square and sits 5mm from the fabric, so not much light really escapes anyway. One important consideration is that there are no metal screws underneath the lasing area, so I'm not going to get dangerous reflections.
Anyway I lived alone and had no pets and I was always present while it operated. For my use I felt the safety was adequate, but obviously for something like university use it would need a full enclosure. This version is a prototype slash proof of concept.
What's scary about this question is the lack of regard to safety in most US manufacturing facilities that employ lasers. Union shops tend to be up to par with safety standards, but if you go to the smaller shops, laser cutting and engraving is often performed by an unsecured machine with broken or missing cabinet parts or optical fencing. I travel to a lot of these shops to perform repairs on a variety of equipment my employer distributes and I can't remember the last time my log didn't include notes to have sales recommend the needed safety measures for the device. This neglect to safety seems to be just accepted by the workers and met with reluctant compliant by management, with everyone pointing to how inconvenient and "unnecessary" some safety measures are.
If anyone things OSHA has a handle on this issue, they are delusional. Without a major accident happening, most of these small shops can play by their own rules simply because the body enforcing them is stretched ridiculously thin.
So, thank you for asking this. It's insane to me how many do not bother to ask.
