Why should paper products not be stored under the lavatory sinks?

Storing paper products under the lavatory sinks presents a significant fire hazard due to the materials being highly combustible. In the event of a small fire, flammable items like paper can easily exacerbate the situation, potentially leading to a more severe fire risk. The area under a sink is often where plumbing and electrical components are present, and any leaks or sparks could ignite the paper products, creating dangerous conditions. By keeping these materials away from such areas, the risk of fire is minimized, ensuring a safer environment on the aircraft.

While maintaining cleanliness, ensuring easier access, and plumbing considerations are important, they do not carry the same level of urgency or impact as the fire hazard posed by combustible materials.