As polypropylene and other propylene derivatives have grown faster than refinery FCC output, some regions face periodic propylene shortfalls. US PDH capacity has expanded to address this domestically, but importers in regions with limited PDH access may source propylene from Middle Eastern or Asian producers with dedicated on-purpose capacity. Trade flows are highly sensitive to naphtha cracker operating rates and refinery utilization globally.

Propylene is commercially traded in three main purity grades: refinery grade (50–70% propylene), chemical grade (92–96%), and polymer grade (99.5%+). Polymer grade commands a significant price premium and is required for most polypropylene production. While all grades fall under the same SITC code, buyers should specify the grade precisely in purchase contracts and import documentation, as mislabeled purity can affect downstream process yields and contractual compliance.