A pressure group that represents the temperature-controlled sector says slightly longer and higher trailers would help improve safety.
Alan Lines, owner of Lines Industries and a member of the technical committee for Transfrigoroute, believes cold air is unable to properly circulate around pallets in a regular trailer, leading to hot-spots in the load. This potentially poses a hazard to health, especially when foods and medicines are being transported.
He adds: "An increase of just 20cm in length and 10cm in height would make a world of difference to the correct air flow around pallets.
"It would enable operators to have the correct spacing at the front and rear of the trailer and give sufficient length and height for a multi-temperature bulkhead to operate at an optimum."
Several trials of longer trailers are taking place in Continental Europe, with trailers up to 15 metres long being used in some member states.
Transfrigoroute will put its findings before a committee in Brussels shortly, and hopes that a standard new length of 13.8 metres will become acceptable across Europe.
The organisation says it does not want the 33-pallet limit to be increased.
Lines says: "We are not trying to increase payloads as some of the trials in Europe for longer trailers are."