What is the minimum design criteria to protect an exposed nonexpanded Group A plastic stored...

To protect exposed nonexpanded Group A plastic stored in a solid pile up to 15 ft high, a design criteria of 0.70 gpm/ft² over 2000 ft² is typically required. This density and area coverage account for the high combustibility and potential heat release of Group A plastics.

References: NFPA 13's guidelines for storage of combustible commodities, which include specific design criteria for plastics based on their combustibility and storage configuration.