An electric vehicle (EV) that is on fire is difficult to extinguish. Among other things, this is because the battery casing is watertight. The ultra high pressure (UHP) extinguishing system appears to be a promising new method of reaching the burning battery. However, RIVM measurements show that with this method, the firefighting water gets heavily contaminated. Collecting the pollutants may help to prevent dangerous situations for people and the environment. This is why RIVM recommends developing this method further.
The number of EVs is growing. As a result, battery fire incidents are also becoming more frequent. It is very difficult to extinguish such fires from the outside, because the battery enclosures of EVs are watertight. Firefighters often submerge the vehicle in a large container of water or allow it to burn out in a controlled manner.
UHP method improves extinguishing process
The UHP extinguishing system among others has been developed to make it easier to put out fires in EVs. This system is able to penetrate the vehicle bodywork, allowing the firefighting water to reach the burning battery. To test this new method, the Netherlands Institute for Public Safety (NIPV) joined forces with a number of partners in 2024 to conduct two fire experiments. RIVM took measurements to identify hazardous substances that were released from the battery into the smoke and firefighting water.
Hazardous substances in smoke, firefighting water and surrounding area
The measurements showed that the UHP method potentially causes more hazardous substances to be released from the battery than other extinguishing methods. This mainly concerns heavy metals such a cobalt and nickel. These are Substances of Very High Concern (SVHCs) that can end up in the area surrounding the EV through the firefighting water.
These SVHCs may contaminate the soil to such an extent that it must be remediated. Heavy metals also pose a threat when they end up in surface water through the sewer. In rare cases, people may suffer skin lesions when coming into contact with the contaminated water. This may occur if the soil is not cleaned up after deployment of the UHP extinguishing system and remains contaminated with hazardous substances. In practice, this is a particular concern in the case of fires in large battery systems.
Recommendations on safe UHP system use
The UHP extinguishing system appears to be quite effective in extinguishing EV battery fires. One downside of this method, however, is the large quantity of hazardous substances ending up in the firefighting water in particular. Consequently, RIVM recommends conducting an investigation into methods to collect the firefighting water. Additionally, RIVM recommends considering the environmental impact when deciding which extinguishing method to use. This will help to prevent hazardous situations for people as well as environmental pollution.