Hi, I am studying ACToR, an open database managed by EPA. Three data models troubled me, which were substance, chemical and compound. I wondered what is the difference between/among them.
I found that both substance and chemical have casrn and name, indicating they are similar (so what's the difference?). Compound is contained in assay results and has SMILES and status, so it should be a pure chemical substance?
The construction of ACToR is complicated and is there any suggestion how to study?