By safe, they mean the anti-prohibition description: Putting the sale and distribution into the hands of trustworthy and accountable individuals and taking the control out of the hands of criminals.
I like this move. While I don't want the government to handle manufacturing of the weed, I agree with taking the trade away from criminals. Now the weed is gonna suck. The government will continually refine the strains to produce the least effect. They will argue this is for safety. Studies will not be able to prove higher THC content provides greater relief and thus they will be able to justify geneticly engineering the high out of weed.