What should tanks and containers for aboveground liquid storage be marked with?

Tanks and containers used for aboveground liquid storage must be marked with both the name of the product and the warning "FLAMMABLE—KEEP FIRE AND FLAME AWAY." This requirement is crucial for safety and emergency response purposes. Proper labeling informs personnel and emergency responders about the nature of the contents, allowing them to take necessary precautions when handling or in the vicinity of the storage units.

Additionally, clear labeling helps prevent accidents that may arise from improper storage or handling, thereby promoting a safer environment in locations where flammable liquids are stored. Each of the other options lacks critical safety information: relying solely on warning signs does not convey the specific hazards of the materials, only displaying the manufacturer's name does not inform about the dangers of the product itself, and stating that no markings are necessary if tanks are locked is misleading, as potential hazards still exist regardless of security measures.