Following a number of incidents involving white powder deposits being found on food cargoes that have been transported in refrigerated containers, UK P&I Club has issues some advice. The presence of aluminium oxide/hydroxide, which appears as white powder deposits on food cargoes, can result in lost transportation revenues, customer rejections, insurance claims and even government mandated destruction of the food cargoes. George Radu, Claims Executive at UK P&I Club, comments on how this cargo loss can be prevented.
“One of the most important steps in preventing white powder deposits on food cargoes is ensuring that guidelines are both in place and enforced relating to the interior cleaning of refrigerated containers. These guidelines should also outline which gasses should not be put into the containers in large quantities when the cargo is being loaded.
“The container used to carry susceptible food cargoes should also be chosen with care. Refrigeration should be turned off, exterior evaporator fan cover plates removed and aluminium alloy/metal inspected for signs of corrosion issues. If corrosion is present, the problem should either be corrected or another refrigerated container selected to carry the food cargoes.
“Another action that should be taken to avoid white powder deposits is either replacing aluminium alloy stator housings with housings made from materials with better corrosion resistance or, alternatively, treating existing stators housings with corrosion resistant coatings such as marine grade epoxy paints.
“It is also important to conduct appropriate tests and inspections of the refrigeration units and container boxes to make sure that adequate precautions have been taken to avoid the galvanic corrosion that can be caused when dissimilar metals come in contact.
“Containers should comply with most recent US Food and Drug Administration regulations, such as ‘shipper’ specified interior refrigerated container cleaning instructions and processes involving the Sanitary Food Transportation Act and the Food Safety Modernization Act. The new rules address, in part, risks to human or animal health associated with the transportation of food.
“When acquiring refrigerated containers, both design and performance specifications should be published to show how the container design is safeguarded to prevent and supress corrosion, which may include coatings and corrosion resistant aluminium alloys.
“There is no short term fix to avoid corrosion caused white powder deposits on food cargoes. But by implementing the above recommendations, the likelihood of white powder deposits becoming a recurring problem can be significantly reduced.”