A major hazardous materials emergency is unfolding in Garden Grove after a large industrial chemical tank began leaking toxic vapors at an aerospace manufacturing facility on Western Avenue. Authorities say the situation remains unstable, with emergency crews warning the tank could either rupture or potentially explode if conditions worsen. 

Toxic Chemical Leak in Garden Grove Triggers Evacuations and Health Warnings

What Happened?

The incident began Thursday afternoon at the GKN Aerospace facility in Garden Grove, where firefighters responded to reports of a leak involving a 34,000-gallon storage tank containing methyl methacrylate (MMA), a flammable industrial chemical used in acrylic plastics manufacturing. 

Emergency crews say the tank experienced rising temperatures and pressure buildup, creating fears of a “thermal runaway” event — a dangerous chain reaction that can cause tanks to rupture or explode. Firefighters have been continuously cooling the tank with water streams while hazmat teams attempt to stabilize the leak. 

Officials described the situation Friday as “actively in crisis.” 

What Chemical Is Involved?

The leaking substance, methyl methacrylate (MMA), is commonly used to manufacture plastics and acrylic materials for aerospace and industrial products. According to emergency officials, MMA is:

• Highly flammable
• Capable of producing irritating vapors
• Able to generate heat during chemical reactions
• Dangerous in enclosed or poorly ventilated areas 

Possible Exposure Symptoms

Residents near the affected area may experience symptoms if exposed to MMA vapors, especially outdoors or downwind of the facility. Reported health concerns include:

• Eye irritation
• Burning nose or throat
• Headaches
• Dizziness
• Coughing or breathing discomfort
• Skin irritation
• Nausea in higher concentrations 

Emergency officials say there have been no confirmed fatalities or major injuries reported so far. 

Evacuation Zones and Closures

Mandatory evacuations have expanded across portions of:

• Garden Grove
• Stanton
• Cypress
• Parts of Buena Park

Authorities say the evacuation perimeter currently stretches approximately:

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

Several schools and outdoor activities in nearby districts have also been canceled or closed as a precaution. 

Evacuation Centers

Officials have opened emergency shelters at:

• Garden Grove Sports and Recreation Center
• Cypress Community Center

Danger Level

Emergency officials are treating the incident as a serious public safety threat due to:

• The chemical’s flammability
• The possibility of airborne vapor exposure
• Concerns about tank failure or explosion
• Nearby fuel and chemical storage tanks that could be affected in a chain reaction 

Authorities have urged residents not to ignore evacuation orders.

What Residents Should Do Right Now

Officials recommend the following precautions for anyone near the affected area:

If You Are Inside the Evacuation Zone

• Leave immediately if ordered to evacuate
• Follow official police and fire instructions
• Avoid driving toward the incident area
• Bring medications, pets, and important documents if possible

If You Are Nearby But Outside the Zone

• Stay indoors
• Keep windows and doors closed
• Turn off fans, swamp coolers, and HVAC systems pulling outside air
• Avoid outdoor exercise or activities
• Monitor local emergency alerts and news updates

If You Feel Exposure Symptoms

• Move to fresh air immediately
• Wash exposed skin with soap and water
• Seek medical attention for breathing difficulty, chest pain, or severe irritation
• Call 911 in emergencies

Orange County has also activated a public information hotline at (714) 628-7085 for residents seeking updates. 

Ongoing Investigation

Officials say the exact cause of the leak remains under investigation. Hazmat teams, firefighters, and industrial cleanup specialists continue working to stabilize the tank and prevent further escalation.