PVC Primer IS safe - so is the cement.
I just made a spray bar from 1/2 inch pvc - I coated the bar with purple primer to make it blend in more to the black background - which it did, and since it sits in the back my plants hide it.
But I used cememebt and lots of primer - dried it with a hair dryer and 1/2 hour later put it to use, no problems
Thats my 2 Cents US
125 Gal - 3.07wpg - 99% flourite - Pressurized Co2 - Uv Sterilization when needed - Densly Planted