All materials stored in tiers must be secured to prevent what?

The correct answer emphasizes the comprehensive need to secure materials stored in tiers against multiple hazards, including collapse, falling, and sliding. When materials are stacked or stored in tiers, improper securing can lead to a range of dangerous situations.

Collapse refers to the structural failure of the stacked materials. If materials are not secured and are stacked too high, they can lose stability and fall over, which can pose significant risks to workers and damage to property. Falling and sliding are specific forms of collapse, where materials may dislodge and tumble down, either unintentionally shifting position or outright toppling due to insufficient support or incorrect placement.

By acknowledging that all these conditions can occur and that all must be considered when securing tiered materials, the answer highlights a holistic approach to safety in storage practices. Ensuring that these materials are secured is key to maintaining a safe environment, one where the risk of accidents is minimized.