GKN Aerospace has begun limited safety checks and machine calibrations at its Garden Grove, Calif., facility following a May incident involving a storage tank containing methyl methacrylate (MMA).

According to the Orange County Health Care Agency, select employees returned to the site on Monday, June 15, to conduct safety checks and machine calibrations as the facility begins the first steps needed to restart some operations in parts of the facility that were unaffected by the incident. The agency said the work involves operations such as forming, lamination, machining and assembling transparencies, and does not involve MMA or the manufacturing of acrylic.

Cleanup and waste-removal activities related to the incident remain under the guidance and approval of Unified Command, which includes the Orange County Health Care Agency, South Coast Air Quality Management District and GKN Aerospace. Air monitoring continues at the facility perimeter and in the surrounding community. According to the agency’s June 15-18 update, air monitoring data has shown no elevated readings, with all data remaining within typical levels since the start of the cleanup phase.

The incident began May 21, when GKN Aerospace personnel identified elevated temperature readings in a storage tank containing MMA, a chemical used in the manufacture of high-strength aerospace acrylic materials. As conditions evolved, the Orange County Fire Authority issued mandatory evacuation orders for portions of the surrounding community as a precaution. GKN said evacuation orders were partially lifted May 25 and lifted in full May 26, with OCFA reporting there was no risk to the public.

GKN said a review is underway to understand what took place. On its Garden Grove community update site, the company said any reopening will be done carefully and in coordination with the appropriate agencies and officials.

MMA is an industrial chemical used in the manufacture of acrylic materials, coatings, composites and specialty components, including aerospace applications. GKN said its Garden Grove facility manufactures advanced aerospace canopies, cabin windows and flight deck windows for commercial and military aircraft, as well as spacecraft.

The company has also announced community support initiatives connected to the evacuation. GKN said it funded $3 million to Orange County United Way’s OC Community Resilience Fund and committed an additional $1 million to broader community initiatives across Orange County. The company said those funds follow an earlier $1 million contribution to the American Red Cross to support residents directly impacted by evacuation orders.

Sources: Orange County Health Care Agency, GKN Aerospace

PCI reported on this incident and another chemical tank incident that occurred around the same time. Read PCI's Chemical Incidents Raise Storage Safety Questions article.