Please, use adequate ventilation (with a heat exchanger if you need to keep A/C in the room) if you're going to be resin printing inside. I don't want to see all of you guys get cancer from this hobby.
He literally presents a list of reasons around 5:12. Then he goes on to describe how formaldehyde already affects him.
Resin priting can be a lot of fun, but he's correct: that shit is toxic. It needs to be respected, and he's also correct in pointing out the carbon filter on many printers is basically a placebo for the consumer.