Why pre-ventilate

Unpacking or inspecting shipping containers may cause involuntary exposure to harmful chemicals

Click here for link to publication

An estimated 260,000 man-years are required to unpack shipping container in the whole world. In our studies, we found that about 12% of all arriving shipping containers to Sweden had levels in the air of harmful chemicals above the occupational exposure limits and 4% had carcinogens over the limits. In warmer climates the figures are likely higher. Harmful chemicals can have accumulated from the natural emissions given off from the goods and packing material, they can be the cause of damaged goods or they can be deliberately added for fumigation purposes. These gases accumulate inside the poorly ventilated containers and upon arrival may have reached toxic levels. Many harmful volatile chemicals have no warning properties, like odor. In most cases, measurements with advanced instrumentation is the only way to identify and determine the correct levels.

Unless a container has been determined to be safe, we recommend pre-ventilation before opening and entering. Our method of pre-ventilation lowers the arrival concentrations to 10% or less, within just a few hours. In most cases pre-ventilation can be done even before the container´s seal is broken and the doors opened. The only time the container doors needs to be temporarily opened is when the corner vents have been taped from the inside.  The tape from the nearest vent is removed (if possible), the door closed and the evaQplate attached to this cleared vent.