It would seem that moisture is condensing from the warm, vapour laden air content of the powder. The simple answer would be to cool the powder elsewhere before loading into the containers, but this is probably impractical and may be unnecessary. The real question is does whether this free moisture gives rise to any operational or quality problem and then whether it is cheaper to deal with the problem than avoid it. More details are needed of the life cycle of the material to understand how best to approach this situation. ■