Lafcarr sirens in action: chemical fire in Zuera

On 28 July 2025, a chemical fire broke out in Zuera at the Union Derivan plant (El Campillo industrial estate). Given the risk of toxic emissions, the Government of Aragon activated Level 1 of the External Emergency Plan, triggering the public warning systems to minimise exposure for residents and workers.

In this article we look at how the early warning sirens performed, why maintenance is key and why it is important always to follow official instructions from Civil Protection and 112 Aragon.

Union Derivan and the emergency protocol

Rapid coordination between the Fire Service, Local Police and Civil Protection meant the audible alarms were activated immediately. The sirens emitted clear, continuous signals, alerting residents of Zuera and San Mateo to shelter in place as a precaution.

How the Lafcarr sirens performed

In this incident, Lafcarr's early warning sirens proved their effectiveness:

• Immediate activation from the Aragon Emergency Centre.
• Optimised acoustic coverage for industrial areas, ensuring a clear signal in homes and critical zones.
• Multimodal integration with public address, radio and digital notifications.
• High reliability thanks to preventive maintenance and scheduled tests.

Self-protection advice in case of a toxic cloud

• Stay indoors and close doors and windows.
• Switch off air conditioning and ventilation systems.
• Listen to local radio stations for instructions and advice.
• Turn off the gas and disconnect the electricity.
• If you are outdoors, cover your nose and mouth and take shelter indoors.
• Do not go outside until the end of the emergency is declared.
• Do not use ventilation systems, to stop toxic or flammable gases getting in from outside.
• A vehicle is not a safe place to stay. Take shelter in a building.

Follow this advice and do not go outside until it is safe. The all-clear will be given over public address, social media and the news media.

In an emergency, call 112.

Official sources and advice

Although sirens are essential for the initial alert, you should always follow first and foremost the announcements from Civil Protection, 112 Aragon and other competent bodies, which give instructions on sheltering, evacuation routes and air quality.

Conclusions

The Union Derivan incident shows how important it is to have robust, well-maintained warning systems. Effective early warning provides valuable minutes to react and protect lives.

We continue to work with the authorities to make communities more resilient to chemical and technological emergencies.

More information

For official details and updates, see:

• Aragon Civil Protection
• 112 Aragon