We are looking to convert to R290 refrigerant for our product line. We will be building a test room where we can charge our units with R290 and test them. This room will be equipped with a ventilation system that will automatically turn on if propane is present and the room will also be explosion proof. I have attached the research documentation that we have reviewed and I am not finding much concerning NFPA standards. Looking for any assistance with R290 and the NFPA standard.