Hi,
Tbh, id of thought it would of been alot easier and safer to use the primer that goes with the system you are using.
As Geeg has said if used properly then acid primer is safe to use, i used to be a bit unsure about acid primers but i bought
Doug Schoons book called Nail structure and Poduct Chemistry , there is a section in there about primers that makes very good reading and it totally put my mind at rest.The whole book actually is fantastic reading, and if you havnt got it already i would defo get it !
I use Ezflow products and i can say that none of my clients have any issues/problems with the acid primer and if i want or need to use a primerless system i just use Ezflows HD range.
Haze x