When selecting emergency lights, prioritize Battery Type and Capacity, typically Lithium Iron Phosphate (LiFePO4) or Ni-Cd, ensuring a minimum discharge duration of 90 to 180 minutes depending on local fire codes. Pay close attention to Luminous Flux (Lumens); for high-ceiling warehouses, a minimum of 300-500 lumens is recommended, while standard corridors may only require 100-150 lumens. Additionally, verify the IP Rating (Ingress Protection), where IP65 or higher is mandatory for outdoor or industrial environments to resist dust and moisture.