When using sweetened condensed milk, it is absolutely vital that the greatest care is taken to prevent external contamination. The product itself is inherently stable due to the heat treatment and the high sugar content, but the greatest risk of external contamination begins at the point of exit from the bag.
The risk factors are from airborne bacteria or from dirt from a variety of sources within the manufacturing environment, and good manufacturing practice will keep these to a minimum.
When emptying the pallecon, the place of discharge must be clean and dry, and preferably sited away from both pedestrian and vehicular traffic to avoid the disturbance of air, which itself raises the risk of airborne particles of dirt as well as airborne bacteria.
As the container is emptied, the inner bag will collapse. The discharge valve and all connecting pipework must be kept scrupulously clean, either by steam cleaning or by liquid alcohol or similar if there is no CIP system in use.