That's not how any of this works. Metabolism (reactivity by proxy) and enzymatic/inhibitory activity are orthogonal. One of the least reactive metals, Platinum

That's not how any of this works. Metabolism (reactivity by proxy) and enzymatic/inhibitory activity are orthogonal. One of the least reactive metals, Platinum, is an excellent catalyst in numerous reactions, but often found entirely unreacted in nature: https://en.wikipedia.org/wiki/Platinum https://en.wikipedia.org/wiki/Platinum a stable chemical can have catastrophic consequences for various species, if it is a potent agonist/antagonist in a critical signalling pathway, or an enzyme/inhibitor of some process. Often these effects are clinically relevant in nanomolar concentrations. The stable chemical DDT is so stable, it actually bioaccumulates, with biological half-life in decades. It's also a known carcinogen that elevates risks of cancer 4-5x simply from historical exposure decades ago. As for "biodegradable", that's often basically fraud. PLA (polylactic acid), one of the most common greenwashing plastics, does not biodegrade at all under common conditions, outside of very specific composting process, not usually (maybe even never?) found in nature. Luckily PLA isn't very toxic.