What factor must be considered when determining the order of loading dissimilar products through the same piping system aboard a tanker?

When determining the order of loading dissimilar products through the same piping system aboard a tanker, contamination of the cargo is a critical factor. Different cargoes may have varying chemical compositions, which can lead to undesirable reactions or alterations in quality if they come into contact with one another. Contamination can occur if residues from one product mingle with another, affecting the purity and marketability of the final cargo.

Proper procedures must be established to prevent this contamination. This might involve careful consideration of the sequence in which cargoes are loaded or the use of dedicated pipelines for certain products. Additionally, if contamination occurs, it can result in significant financial loss, legal repercussions, and environmental damage, making it imperative to prioritize this factor when planning loading operations.

While flash points, specific gravities, and Reid vapor pressures also play essential roles in cargo handling—such as assessing safety risks and compatibility—contamination fundamentally governs product integrity, which is why it is the primary concern in loading order.