What is the safest method for storing oily rags?

Storing oily rags safely is crucial to prevent fires, as these rags can spontaneously combust if not handled properly. Hanging them up on a hook in a well-ventilated location allows any volatile compounds in the oils to dissipate into the air, reducing the risk of ignition. Good ventilation prevents the accumulation of heat and allows moisture to evaporate, which are essential factors in avoiding the conditions that might lead to spontaneous combustion.

The other methods may not provide the same level of safety. Sealing oily rags in a bag can create an airtight environment that traps heat and gases, increasing the risk of fire. Storing them in a bucket filled with water, while it may seem safe, can also lead to issues if the water evaporates and the rags are left to sit. Keeping them in a cupboard away from machinery does not adequately address the fire hazard posed by the oily rags themselves, especially if airflow is limited. Thus, the method of hanging them in a ventilated area is the most effective approach for maintaining safety.