Ya, but what products? I'm sure California understood that it would be difficult for property managers to do a complete audit, so allowed this warning as a cop out (it might be that they have none of those chemicals, but who knows, we will put up the warning just in case).

It always trickles down. The property managers know who built the buildings. The construction company knows what companies produced the construction materials. The company that made the construction materials knows what chemicals are in them. That's the person who writes the warning, and the construction crew tells the property manager, and the property manager keeps a list in their office for public viewing.

I think it has more to do with the gardeners and maintnence than the orig construction. But ya, they so much as use a floor cleaner from the grocery store, that would have to be documented.

Depends what it's made of. An asbestos apartment building is kinda toxic.

Sure. Also, no one on china trusts each others apartment renovations for this reason, which is why you are expected to re-renovate every time you buy (and your own renovations do nothing for the resale value).

That stuff is actually easy to track down is what I meant. It is the day to day stuff that isn't.