There are some important rules that the producers should respect and which are written in the Hazard Analysis and Critical Control Point book. For example, one of them says that the vegetables can not be stored near to dairy products. Also it is claimed that it should be provided separate space for cooling and storage the chicken meat.
But it is said that these refrigerated trailers come with the big disadvantage that they are not very resistant. They have a special construction and they are very sensitive. If refrigerated trailers are not used properly, they can cling to trees. This is the reason why, many times the roof insulation breaks down and the infiltrations appear in billboards. This is like a real cancer for the van which leads to the loss of properties and which increases the weight of the trailer with about 200-300 kg.
Because the risk of damage is very high, to maintain refrigerated trailer in good condition inspections are required - at least visually. There are people who are very good at inspecting a trailer and who can realize immediately when something does not work as it should. Another solution is choosing good quality refrigerated trailers. Some of the best such vehicles are produced in United Arab Emirates.
In any case, it is highly recommended for a refrigerated trailer to be changed after five years - although the indoor temperature can be maintained very well. Problems may appear, especially during the ferry crossing, where the driver does not embark the cargo. The responsibility of embarking the cargo is taken by a manipulator who is not always very attentive. So, the refrigerated trailer may suffer a lot of damages. However, if it is used properly, the life of a refrigerated trailer can be up to 10 years.
On the other hand, it is important to notice that, sometimes, the drives are afraid to talk about the damages because they do not want to pay for them. So they prefer to hide them, as well as possible. But, if they are resolved in time, these damages are not very expensive. And also it is important to say that the buyers should be careful when it comes to the second hand refrigerated trailers.