NFPA 326, titled Standard for the Safeguarding of Tanks and Containers for Entry, Cleaning, or Repair, is a vital guideline developed by the National Fire Protection Association (NFPA) to ensure the safety of personnel working in tanks and containers that contain or have contained flammable, combustible, or otherwise hazardous substances. This standard provides comprehensive procedures to safeguard these vessels before entry, cleaning, repair, or other activities are performed.