Where should partially burned papers ideally be stored until completely cooled?

Storing partially burned papers in a secure, metal container is the best practice because this type of container is designed to withstand high temperatures and helps prevent the risk of ignition from any smoldering embers. Metal containers are non-combustible and can contain any potential fire that may arise from the cooled materials, thereby minimizing the risk of a fire spreading.

This method ensures that any remaining heat is safely contained until the materials are fully extinguished and cool. In contrast, storing partially burned materials in a trash can could present a fire hazard, as a trash can is often made of flammable materials and may not contain any residual sparks or heat efficiently. The refrigerator is not a suitable option because it is not designed to store hot or smoldering materials and could create a fire hazard within an enclosed space. An open bin offers no protection against external elements or potential ignition sources, making it a risky choice for storing partially burned items.