There are really no enforced safety codes at the moment.
A recent survey of edible marijuana in Colorado found E. Coli, pesticides, herbicides, fertilizer, and high levels of certain metals.
I don’t intend to go that way my friend but thanks for your concern - I am just hopeful that the plant may be used in a way that safely benefits people. I get arthritis in hands and feet plus a bad back - I noticed that there are some topical creams that are supposed to have some effect on pain without any psychotropic effect at all. I doubt they are available here in Australia or if they are they might be hard to find and not produced under any great scrutiny - but who knows the near future may change things.
Mel