I mean from what that study describes there might be some toxic properties at high-ish doses: the 60mg/kg/day showed no effects. That would mean 3.6g for a 60kg human sized rat taken orally, which is quite a lot to accidentally eat. I think the limit is 5% TPO in the nail products, so you’d have to be trying to ingest it.

But my original comment is that I don’t think there’s much relation with phosphine.