Hemoglobin

The fact that your mind went immediately there is a little worrying... Is everything alright?
And I'm not shaming you or being sarcastic, just talk with someone if what I'm saying is true

You're the only one talking about suicide here.

if naming a common chemical that can cause poisoning immediately makes your mind go to suicide methods, dont go to the communities that name common chemicals

I mean, you can even suicide on water (inb4 dihydrogen monoxide memes). This is just normal biology of a normal thing in the world.

Heck, forget water: you can even suicide on the ground below your feet. It's just usually lots more work.