[bawolff]

> The line to be crossed is obviously at least a few blocks up the way from "what is the difference between water and hydrazine though".

Do you actually have a line? We can't make a law out of people saying "you know what i mean".

[naremu]

> the colloquial definition of chemicals which if we're not being pedantic, we know brings up ideas of substances damaging to other substances or life itself.

From the comment you're responding to. Damage is quantifiable, if it wasn't, the OP (EPA proposing hazardous substance classification) wouldn't even exist.

[bawolff]

one presumes it is not when there is any quantifiable damage, no matter how slight. I assume nobody is proposing banning water, etc. But even plain water can result in large amounts of environmental damage in certain contexts.

If the point is just to ban things when the risks outweigh the benefits, that is simply the status quo.

[lazide]

The challenge is, one can usually only make that kind of trade off when something is well known enough to know the risks and benefits in a wide variety of environments.

The first real problematic PFAS compounds were in fire fighting foam used to put out aircraft fires for example, and took decades for their problems to show up.

Which requires either extremely exhaustive (or essentially impossible economically) testing, or yolo’ng it. Or only using already known compounds.