YGC agar & inoculation

lets say my teacher said that I should make BHI and add YGC agar (glucose, yeast and chloramphenicol) to cultivate microorganiszms like E.coli, Bacillus subtillis, Listeria inocua and so on...isnt the chloramphenicol gonna be harmfull towards the MO?
when i pour the agar into Petriho dish can I do inoculation (plate streaking) on the same day or should i wait until it become really stiffen (tthe next day)??