I mean, people never talk about the fumes either. I tried one in my bathroom with the fan on, and idk, my eyes were burning for hours. Maybe it's just me but that stuff can't be good to breathe in, plus the hair damage on top of it.
Many DIY keratin kits list formaldehyde as a main ingredient. That chemical turns into gas super easy, so those fumes are EVERYWHERE in your bathroom. It's not just about burning eyes, it's a known irritant that can affect your breathing over time. The problem is people think opening a window is enough, but that gas clings to surfaces like towels and walls. So the risk lasts longer than just during the treatment, which is SCARY. You're right to worry about more than just hair damage.