[mxmbrb]

Thats common chemical knowledge. Don't be that guy.

Still, as other pointed out, he missed the point by a mile.

[mandmandam]

Here's the thing: there's a big gap between some scientific terms and terms as normal, ie, most people understand them. In this case, the word is 'inert'.

I don't think it's at all unreasonable to want to know who is telling people PFAS are inert, with the implication being 'safe'. Nothing 'that guy' about it.