When pallets are stored outside, what is required for each stack of ten pallets?

When pallets are stored outside, a plastic barrier is required for each stack of ten pallets to provide protection from moisture and environmental elements. This barrier helps to prevent the wood from coming into direct contact with the ground, which can lead to deterioration and contamination. Additionally, using a plastic barrier minimizes the risk of mold and mildew developing on the pallets, ensuring that they remain in good condition and safe for use when needed.

The other options do not adequately fulfill the protective purpose required for outside storage. While metal frames and wooden pallets can offer some structural support, they do not offer the necessary moisture protection that a plastic barrier provides. An inspection tag, while important for tracking purposes, does not provide any physical protection to the pallets in outdoor settings.