There are lots of things that can be detected rather simply in a lab though. Like running a bioassay to ascertain activity at various receptors. Bisphenol A for

There are lots of things that can be detected rather simply in a lab though. Like running a bioassay to ascertain activity at various receptors. Bisphenol A for instance has interactions with several hormone receptors. A single in vitro study is enough to label BPA as biologically active and therefore a potential risk. Similarly, some PFAS compounds are now known to interact with certain receptors involved in lipid metabolism. So it can also be determined as biologically active in vitro. There's just so much more that can be done about this on the regulatory side than is done currently.