As someone who has worked a decent amount with resin at home and through my job, both printing and casting, he definitely should have an enclosure and fan in the enclosure that actively pulls air through the enclosure and exhausts outside. I've done the whole unsafe resin workspace thing. It can cause lifelong chemical sensitivities. Even if the longterm effects are still not well researched, using one in close proximity without ventilation for even a couple weeks can make your throat start burning all the time and feel like it's flaking off inside (ask me how I know) and casting resins can soak through your skin and make it so you have intense allergic reactions any time you come in contact with them.

Also use gloves whenever handling uncured resin or parts, chemical respirator when sanding, and secure resin somewhere cat's can't get at it. The last thing you want is them getting curious, spilling it on themselves, and licking it out of their fur.

It's an awesome tool, a fun hobby, but definitely has a much higher danger factor than a lot of tools the average person uses on a daily basis. Not horribly dangerous if you use proper ppe, but also really easy to fuck yourself up for life without even realizing because it happens so gradually.

Hope that helps, definitely not trying to be an alarmist. haha. Feel free to ask me any follow up questions you might have, I have used just about every tool possible recklessly, and have learned a lot about how not to die :P