Which of the following is NOT a requirement for storing materials safely?

Stacking materials without any additional support is not a safe practice and therefore is the correct choice as something that is NOT a requirement for storing materials safely. Proper storage involves ensuring that materials are stable and secured to prevent accidents and injuries. When materials are stacked without any support, they can easily become unstable, increasing the risk of them toppling over and causing harm to individuals or damaging other materials.

In contrast, keeping aisles and passageways clear is essential to ensure accessibility and prevent tripping hazards. Storing materials to prevent sliding and falling is crucial for maintaining a safe work environment, as it minimizes the chances of materials unexpectedly dislodging. Additionally, ensuring that materials are kept away from hoist-ways is vital to prevent interference with lifting operations and to maintain a clear path for movement and operations. Together, these practices contribute to a safe and efficient storage environment.