The board has postponed four previous votes on a proposal that would force drug makers to design and pay for a disposal program for unused prescriptions and sharps.
The environmental review process will delay the removal of lead-tainted soil from homes in an expanded cleanup area until May or June of 2017.
California's doctor-assisted suicide law takes effect Thursday. Doctors who agree to participate can provide lethal drugs to terminally ill patients who qualify.
Regulators had ruled in 2014 to take no further action to deal with elevated levels of lead at the Watts housing complex. An email scandal prompted the second look.
The county had stopped the cleanup of displaced residents' houses on Sunday, saying it was inadequate. About 2,500 households still have not gone home.
A state agency reviews its decisions to take no action on possible toxics contamination. The focus is on two scientists who had exchanged racially-charged emails.
A lawsuit accuses the Santa Monica-Malibu Unified School District of violating federal law by failing to remove PCB-laden caulk from three schools.