3DPrinting

To be fair, YouTube cultivated this environment because their users respond to it. If users stopped clicking on clearly-clickbait videos, YT would stop pushing them, and creators would stop making them.

Don't breathe it; don't get it on your skin and wear safety glases. Don't flush it down the toilet.

Gloves: Those single-use gloves are spill protection and nothing more. If you can avoid touching resin avoid it and swap them immediately if they contact resin. Keep in mind that approx. 1-2 gloves per box (100 pcs.) can have holes/defects.

For waste treatment: Follow local guidance. As a rough rule of thumb: expose the resin to the sun (fully cure it), let the IPA evaporate and dispose it as a solid.

Flammable liquid storage: Keep the amount stored (inside) as small as possible. If the room is an escape route move your IPA washing station to a different room. Obviously, have a smoke detector in every room of your household, test them every few months and replace after 10 years.

How to check for contamination? Most printer resins are UV-reactive. Get a handheld UV-lamp/black light (those to check bank notes) and if anything lights up in green (fingerprints or spots) you have contaminated it with resin at some point (unless the object/material is also UV-reactive). Especially at the beginning, such a device is useful for learning good work practices (e.g. resin on the glove and touching the curing station or spills on the silicone matt around the washing station).

Any chemical is as safe as you make it: If you are careless it's dangerous. You do your homework and it's suddenly safe to use.

If you don't feel safe or scared by a chemical don't work with it. In this case ask around if somebody already does resin printing and get familiar with it before doing it on your own.

Health and Safety says:

Don't breathe in the fumes.

They mean sensitization. It's where you react more strongly to exposure the more you're exposed. It's a problem for a couple of reasons. The scary one is some people move along the reaction continuum from "mildly annoying" to "oh shit call an ambulance" pretty fast. It's not common but it happens. I actually have a condition that predisposes me to that so I always carry an epi-pen. Good times.

The more mundane one is, even with controls to remove fumes and PPE to avoid them, it's not uncommon to still be exposed to a small degree, especially in a hobbyist setting. Let's imagine you're lax on avoiding exposure and become sensitized due to prolonged and/or heavy exposure, so you set up proper controls to try to avoid it. Now the small amount of remaining exposure which may have never been a problem with proper controls may actually become a problem. Now you can't work with that material at all without having some sort of reaction.

Even when you cook food there are volatile organic compounds all around you and nobody would say they're dangerous.

I'll check the manuals after mixing up this sweet bleach and ammonia cleaning spray.

And the difference being that those VOCs are not specifically isomers which are carrying polymers for additive manufacturing. Volatile meaning they are airborne (or readily made airborne at least, it has to relate to vapor pressure), organic meaning that they've got carbon bonds which readily interact with other elements.

Plenty of people have already suffered anaphylactic shock and other immune sensitivities from coming into direct contact with resin. These sensitivities are permanent. There is no reversing them.