a plastic pallet has reinforcing beams which fail during a fire due to the effects of heat , so the pallet prematurely collapses and thus the rate of heat evolution is diminished , sufficient to meet fire standards . in one embodiment metal beams embedded in the plastic of the pallet have lengths which are shorter than the span between the rails of a pallet rack . they drop down and cause pallet collapse , when the surrounding plastic softens or melts . in another embodiment , the beam is a metal , fiberglass or graphite reinforced composite thermoplastic , which loses strength when the matrix softens or otherwise fails . in another embodiment , a metal beam has two parts which are connected by a thermoplastic fitting which softens and the fails during a fire .