The Rockton Fire Protection District ruled the cause of a fire June 14 at Chemtool’s facility as accidental. The plant manufactures petroleum-based lubricants.

According to the Rockton Fire Protection District, a project was underway at the facility to replace insulation on an elevated heat transfer piping network. The network was part of the site’s system for heating vessels used in the manufacturing of lubricating greases. This network of piping carried heated mineral oil.

An outside contractor performing the insulation replacement was using a scissor lift to access the piping network. Shortly before 7 a.m., while the employee was working in the area, a release occurred from the elevated piping. An unknown amount of mineral oil immediately began falling and pooling on the floor in the area of origin, the Rockton Fire Protection District said.

“At the present time, the most credible scenario is that the scissor lift struck a valve or other piece of piping with sufficient mechanical force to cause the release of mineral oil,” Rockton Fire Chief Kirk Wilson said in a press release.

Chemtool operators detected the release and shut down the boiler. They were in the process of placing containment booms and de-pressuring the heat transfer piping network when the fire ignited.

According to the U.S. Chemical Safety and Hazard Investigation Board (CSB), which monitored the incident, all 70 workers in the facility were evacuated without injury. One firefighter suffered a minor injury and was transported to a local hospital, the CSB said.

The CSB deployed two of its senior leadership members on June 22 to meet with Chemtool regional and site leadership, the on-site federal and local emergency responders, the Environmental Protection Agency (EPA), and the Occupational Safety and Health Agency (OSHA).

Chemtool is a division of the Lubrizol Corp.