CO2 as solid particles can cause electrostatic discharge!
In September 1953, an aircraft fuel storage farm was taken into use in Niederstedem, Germany. The automatic fire extinguishing system, which used CO2, was demonstrated to visitors on the roof of the storage tank. The tank containing an explosive mixture suddenly ignited and exploded. 29 people lost their lives in the incident.
CO2 is often used in extinguishing equipment. When sprayed, it can cool to -78 oC and form solid particles. These particles can become statically charged, especially due to speed in (dry) air. When charged CO2 particles get close to (grounded) metal, they can discharge and create a spark sufficient to ignite hydrocarbons. This most likely caused the explosion.
CLICK HERE for the full fact sheet.