I’d love some advice from the experts here. I am working on a remodel and we’re planning to convert my attic into an unvented attic with open cell foam on the underside of the plywood supporting the roof shingles. We plan to have our HVAC system in the attic, so there are fire retardant requirements where I live (Bay Area, CA). I’m trying to find open cell foam options that are low VOC, but don’t require drywall on top or a fire retardant spray on top. Any suggestions on options?

As our contractor and I have been digging into this, we’ve found:
– This product from Victory Polymers (https://victorypolymers.org/spray-foam-insulation-products/vpc-hfo/)
– A Huntsman Building Solution rep said that all of their open cell foams that can be used in this capacity are sprayed with water, so are therefore low VOC.

I’m having a really hard time understanding all of the details around these foams and what is just marketing vs not. 

Does anyone know if there are low VOC open cell options that I could use in this application without additional fire retardant?  Would the Victory Polymer option be good?  Are all open cell foam options really low voc?  

Thanks in advance for any advice!!!!