CSB Adds Monaca, PA Butadiene Release Investigation

Yesterday, without any fanfare or announcement, the Chemical Safety Board added a new chemical incident investigation to its ‘Current Investigations’ webpage. The new investigation looks at a butadiene and benzene release that took place at the Shell Polymers Monaca facility in Pennsylvania on June 4^th, 2025. According to local news reports (here, here, and here) there was an explosion and fire at an ethane cracking unit at the facility. There was one minor (heat related) injury.

This brings the total open investigations listed on the page to six. The investigation into the two Austin Powder incidents that was announced by the CSB on June 24^th has still not made it to the ‘Current Investigations’ page.

NOTE: I briefly discussed this incident on June 14^th, 2025.