FBI and EPA raid GKN Aerospace, Orange County D.A. begins criminal investigation related to May hazardous chemical storage tank incident

Most of you are aware of the hazardous chemical emergency incident in Garden Grove, CA last month. A failed valve on a storage tank that contained methyl methacrylate monomer caused the tank to overheat uncontrollably. Fears of a toxic explosion and spill led to the evacuation of tens of thousands of nearby residents.

GKN Aerospace, Garden Grove, CA 

Photo Credit: DigitalIceAge

As we noted in an earlier article, amid all of the news reporting, including print, radio, and TV, no one seemed to be addressing the question as to whether the company, GKN Aerospace, was complying with hazardous waste storage regulations before the incident happened.  This despite the fact that it had been previously fined almost $1 million dollars in January by the South Coast AQMD for alleged violations of its regulations.

Well, that has all changed. Today, with a search warrant issued by a federal judge on June 4, the Federal Bureau of Investigations (FBI) and the United States Environmental Protection Agency (EPA) raided GKN's Garden Grove facility. The warrant authorizes federal agents to sweep multiple buildings and chemical tanks, seize chemical samples, employee training logs, internal safety complaints, maintenance records, and company communication.

The focus of the federal probe is on whether GKN violated the provisions of Title 42, United States Code, Chapter 85, Section 7412, which deals with hazardous air pollution.

In addition, the Orange County District Attorney's office is conducting its own criminal investigation of GKN. A strict preservation letter was issued to the company directing GKN not to modify or destroy any on-site evidence.

There are also about a dozen pending negligence lawsuits from local residents and businesses against GKN and its parent company, Melrose Industries. 

Was the company responsible for the hazardous chemical incident in Garden Grove in compliance with hazardous chemical storage requirements?

By now, most of you have heard of the ongoing emergency in Garden Grove, CA, revolving around a disastrous failure of a storage tank containing methyl methacrylate. Fears of a massive spill and/or explosion have resulted in the evacuation of thousands of residents from their homes since last Friday.

Photo Credit. GKN Aerospace logo (fair use)

Emergency response authorities such as the Orange County Fire Authority (OCFA) have done a great job in keeping the public informed of the current status of the emergency response. We have discussed the incident in previous articles in this blog.

However, one thing we have not personally seen, but, perhaps our readers have, is whether anyone has addressed the following:

Did GKN Aerospace Transparency Systems, the owner of the tank in question, follow/comply with required federal/state/and/or local requirements and procedures for the storage of hazardous chemicals, including the existence of an emergency response plan if required?

In all of the news reporting that we have seen (including our own) nobody has addressed this fundamental issue.

• What federal, state, and/or local regulations for the storage of methyl methacrylate, if any, applied to this facility?
• Was an emergency response plan required and in place, and if so, did GKN follow it? 
• If GKN did follow it, what went wrong in this particular situation that required outside agencies to be called in to take over the response?

It should be noted that in January of last year, GKN settled alleged violations of the South Coast Air Quality Management District (SCAQMD) rules and regulations to the tune of over $900,000. The Orange County Register recently reported on this in more detail. 

To be perfectly clear, we are making no accusations of wrong-doing on the part of anyone. We just would like someone to address whether the company was in compliance with existing regulations and emergency plans or not. 

And, if they were in compliance, was this particular situation, involving a tank of methyl methacrylate monomer that apparently started to polymerize and uncontrollably heat up while a control valve failed, addressed in existing plans or was it simply an unforeseen circumstance?

Please let us know in the comments below if you have any information regarding the above questions, or, if you have any other comments.

California Governor Newsom Declares State of Emergency for Orange County for Garden Grove Chemical Tank Incident

California's Governor Newsom just declared a State of Emergency for Orange County related to the malfunctioning chemical tank in Garden Grove. Fears that a storage tank of methyl methacrylate may fail and spill thousands of gallons of the toxic chemical or even explode next to other toxic chemical storage tanks has led to the mandatory evacuation of thousands of residents in nearby areas. (We discussed this in an earlier article, here.)

Photo Credit: Screenshot, OCFA Facebook video post

The proclamation directs the California Governor's Office of Emergency Services (Cal OES) and all state agencies to address the emergency and support Orange County and impacted local jurisdictions. It also unlocks additional emergency response resources including making state-owned properties and fairgrounds available as shelters for evacuated residents.

Governor Newsom said, "The safety of Orange County residents is the top priority. We are mobilizing every state resource available to support local responders and make sure the community has what they need to stay safe."

Added Director of Cal OES Caroline Thomas Jacobs, "Cal OES continues to work alongside our local partners to support the ongoing hazardous materials response operation. Our role is to coordinate resources, share critical information, and ensure local responders have all the resources necessary to safely respond to this dynamic situation. We are committed to a unified, whole-of-government response focused on keeping our communities safe."

Orange County Fire Authority Unified Incident Commander Craig Covey posted a current assessment of the situation on Facebook this morning.

Current evacuation maps can be found here:  Garden Grove website 

Additional information, including shelter locations, can be found here: Cal OES Community Resource page.

The text of today’s emergency proclamation for the Orange County can be found here.

Mandatory Evacuation Orders issued in Garden Grove, CA, due to hazardous chemical storage tank emergency

Due to an emergency related to a malfunctioning hazardous chemical storage tank, the Orange County Fire Authority (OCFA) and local law enforcement today have issued mandatory evacuation orders for the surrounding facility.

Photo Credit: Screenshot of OCFA and local law enforcement Critical Incident Update

Emergency crews responded yesterday, May 21, 2026, to a hazardous materials call at the GKN Aerospace facility located in the 12000 block of Western Avenue in Garden Grove. The emergency was due to an overheated 34,000 gallon tank containing methyl methacrylate, a highly volatile, flammable, and toxic chemical used to make acrylic plastics and aerospace components. As a result of the overheating, the tank began releasing toxic vapors into the sky.

The initial response to the emergency was to douse the tank with water to cool it own, however, the situation worsened this morning. Additionally, according to OCFA Division Chief Craig Covey, the chemical cannot be safely removed because of an inoperable valve on the tank and is therefore considered to be "unable to be secured and mitigated."

Although there is no active toxic gas plume in the air surrounding the emergency, officials fear that because of the thermal characteristics of methyl methacrylate (a self-heating substance), they are facing a critical thermal runaway threat that leaves them, currently, with only two outcomes:

1. Tank failure, which would result in the spill of approximately 6,000 to 7,000 gallons of the chemical into the immediate industrial complex and parking lot, or, 

2. Catastrophic thermal runaway and explosion, which could potentially impact nearby tanks that contain fuel and other chemicals.

Because of this concern, a massive one-mile buffer zone has been established, resulting in the following mandatory evacuation zone:

• North of Trask Avenue 
• South of Ball Road
• East of Valley View Street
• West of Dale Street

Additionally, the following temporary resources and shelters have been established:

• Stanton City Hall, 7800 Katella Ave., Stanton (temporary shelter)
• Community Recreation Center, 13641 Deodora Drive, Garden Grove (reunification center)

The following school closures have also been announced:

The Garden Grove Unified School District has closed several campuses and district facilities until further notice. All outdoor activities for schools outside the evacuation zone have been canceled.

No injuries have been reported as of yet and specialized HAZMAT teams are still on site attempting to manage the tank.