In designated storage areas for flammable or combustible liquids, which item should not be stored?

In designated storage areas for flammable or combustible liquids, oxygen cylinders should not be stored because they can enhance the combustion process. When exposed to flammable or combustible materials, oxygen supports and accelerates burning, posing a significant safety hazard in environments where flammable substances are present. This risk makes it critical to keep oxygen cylinders in a separate, well-ventilated location designated specifically for such gases, adhering to safety regulations and best practices.

In contrast, while empty containers may potentially pose some risks, they can often be stored safely if they are thoroughly cleaned and deemed free of residual flammable liquids. Cleaning supplies can also be stored as long as they are not themselves flammable. Waste materials can typically be stored in accordance with local safety guidelines as long as they are properly managed and not accumulating in a manner that reflects a fire hazard.