NFPA (Fire) 499

Recommended Practice for the Classification of Combustible Dusts and of Hazardous (Classified) Locations for Electrical Installations in Chemical Process Areas, 2024 Edition
standard by National Fire Protection Association, 04/23/2023

NFPA (Fire) 1910

Standard for the Inspection, Maintenance, Refurbishment, Testing, and Retirement of In-Service Emergency Vehicles and Marine Firefighting Vessels, 2024 Edition
standard by National Fire Protection Association, 10/07/2022

NFPA (Fire) 497

Classification of Flammable Liquids, Gases or Vapors and of Hazardous (Classified) Locations for Electrical Installations in Chemical Process Areas, 2021 Edition
standard by National Fire Protection Association, 04/04/2020