On 07/02/08, plant personnel at the Rohm & Haas facility identified that a tank car containing 175,000 lbs. of methyl methacrylate (MMA) was exhibiting signs of polymerization. Rohm & Haas notified 911, and the Lake Dreamland Fire Department responded. Upon arriving at the plant, and gathering additional information concerning the MMA release, a Level 2 hazmat was declared. This resulted in the mobilization of additional local response resources including the Louisville Metro Health Department, who set up an Area Rae network to monitor for air releases. Initial assessment indicated the presence of MMA at up to 700 organic vapor units (ovu) near the vent of the tank car, and up to 25% of the LEL. Based on concerns that the incident was becoming unstable, Metro Health requested that EPA mobilize, and at 0300 hrs. on 07/03, EPA OSC Art Smith arrived onsite.
Upon arrival, OSC Smith organized a Unified Command consisting of the local fire department, the Rohm & Haas plant manager, the KY State Fire Marshal, and EPA. Application of water to the tank car was effective at knocking vapors down to less than 10 ovu. Plant officials stated the polymerization reaction would proceed until completion, requiring frequent monitoring of the tank shell for temperature to warn of an impending explosion. However, Rohm & Haas informed the responders that the car was built to specifications provided by the chemical manufacturer to accomodate both pressure and temperature changes upon loss of the inhibitor. The fire department concluded that the situation could be managed without continued oversight of the emergency responders and Lake Dreamland Fire, the State Fire Marshal and the EPA OSC demobilized demobilized the scene @ 0500 hrs. on 07/03/08. Metro Health remained onscene to monitor for the presence of MMA releases.
The OSC contacted Metro Health on 07/14 for an update. Full production resumed on 07/06, after conditions with the rail car had stabilized. The rail car has been moved to a remote area of the plant after temperatures peaked and subsided, indicating that the fire and explosion threat had been mitigated. No odor complaints by nearby businesses and residences had been received by the Health Department in the interim.