As I understand the proposal being made, it is essentially to treat these in-commerce products as if they had been on the domestic substances list. They would be treated like other commercial chemicals, therefore subject to the screening process, which is now approaching completion for other commercial chemicals. It's being proposed as an alternative to running all of these in-commerce substances through the new substances notification process, which is quite a detailed assessment process for each substance. From a management perspective, it may make sense given the volume of substances involved.
I'm curious as to how these things never got onto the DSL in the first place.