26 May 2026

MELROSE INDUSTRIES PLC

Ongoing incident at Garden Grove facility in California

On Thursday 21 May, a thermal issue was identified regarding a storage tank containing methyl methacrylate (MMA) at GKN Aerospace's (GKN) Garden Grove facility in the US.  MMA is a chemical used in the manufacture of high-strength aerospace acrylic materials.  Action was taken immediately by GKN employees and emergency services notified.

As conditions evolved through Friday 22 May, the Orange County Fire Authority (OCFA) made the precautionary decision to issue mandatory evacuation orders for portions of the surrounding community to protect public safety while response operations continued.

Since then, technical specialists, the emergency services and the relevant authorities have continued to work closely to resolve the situation, with a focus on ensuring the safety of the local community, employees and everyone else involved.  

As a result of the positive progress that has been made over the last few days and the reduced risk, on 25 May, the OCFA announced that the mandatory evacuation area had been significantly reduced with immediate effect.

At 6pm local time on 25 May, the local authorities confirmed that no injuries, leaks or contamination have occurred.  GKN is working closely with customers on operational recovery and supply plans.

The progress made over the last few days is testament to the continued skill and dedication of all the support teams and services involved.

Further announcements will be issued as appropriate.

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About Garden Grove

The Garden Grove facility in California, operated by GKN Aerospace Transparency Systems, Inc.,  designs, manufactures and provides aftermarket support for advanced military and commercial transparencies employing around 500 people.  For financial year 2025, sales generated by the site were £136 million.