Which of the following storage methods is acceptable for flammable liquids?

Approved metal cabinets are considered the safest and most appropriate storage method for flammable liquids due to their design and construction. These cabinets are specifically engineered to contain flammable substances and are built with materials that can endure high temperatures without igniting. They feature self-closing doors and are often lined with a flame-retardant material that helps to mitigate the risk of a fire spreading.

The rationale for their effectiveness lies in their ability to secure flammable liquids and reduce the likelihood of accidental spillage, vapor release, or ignition. Moreover, they often come equipped with ventilation systems to dissipate vapors, further enhancing safety.

In contrast, open barrels can lead to significant hazards as they expose the liquids to the environment and potential sources of ignition. Wooden crates do not provide the necessary protection against fire risks, as wood is combustible, and the structure may fail under high heat conditions. Plastic containers are generally not suitable for flammable liquids because many plastics can melt or combust at lower temperatures compared to metal, making them less effective in preventing fires.