What type of dust is acceptable in dry-vans but not open tops?

In the context of cargo transport and container inspection, the distinction between acceptable levels of dust in dry-vans versus open-top containers is crucial. Dry dust within normal sweep-out levels tends to be acceptable in dry-vans, which are enclosed and designed to carry cargo in a protected environment. The reasoning here is based on the fact that dry-vans can be thoroughly cleaned, and any dust that is considered within normal levels does not pose a risk to the cargo's integrity or quality.

In contrast, open-top containers expose their contents to external elements, making them more vulnerable to contamination. Therefore, dust that exceeds normal levels would not be acceptable in open-top containers as it can settle on or contaminate the cargo, potentially causing damage or degradation. Thus, while some levels of dust (like those within normal sweep-out parameters) may be considered manageable in a closed environment like a dry-van, anything that exceeds those levels becomes problematic and is therefore not allowed in open-top containers.

This highlights the importance of understanding the operational specifications for different types of containers and the implications of cargo exposure to dust and debris.