Deborah Riva, whose home was destroyed by the blast in Danvers, and Robert Corrieri, who lost his boat, want Salem Superior Court to grant class-action status to a lawsuit they filed Monday against Covington, Ky.-based Ashland Inc.
They claim Ashland delivered highly volatile solvents to a facility that had neither permits nor license to handle them.
The blast in November 2006 leveled the factory shared by CAI Inc. and Arnel Co. was heard for more than 20 miles and knocked homes off foundations. No one was killed or seriously injured.
CAI Inc. and Arnel Co. reached a $7 million settlement with residents.
Ashland has said it wasn't liable for the blast. A spokesman didn't return a call Monday.