Fire safety for electric vehicles in car parks

To address the heightened fire safety challenges associated with electric vehicles (EVs) in enclosed parking environments, the Office for Zero Emission Vehicles (OZEV) has recently issued interim fire safety guidelines for EVs operating within covered car parks.

Here, we provide an overview of these guidelines, serving as a useful resource for anyone involved in the installation of electric vehicle charge points in car parks.

Who the guidance is intended for 

The guidelines are primarily intended for individuals and entities involved in designing or retrofitting spaces for EVs and electric vehicle charging points (EVCPs). This includes parking lot operators, designers, risk assessors, and owners of covered parking facilities. The development of these guidelines was a collaborative effort involving fire safety organisations, car parking groups, and the charge point industry.

The guidance considers road passenger EVs (i.e. cars and vans only), with lithium-ion batteries, which are currently most common. It evaluates the likelihood and impact of EV fires, which may arise within a covered car park.

Legal status of the interim guidance 

The stipulations of this  document do not carry legal compliance standards. It also does not replace existing regulations or the need to comply with them, nor does it directly support compliance with:

• The functional requirements of the Building Regulations 2010
• The Regulatory Reform (Fire Safety) Order 2005

It is the responsibility of those who need to adhere to the above (and any other relevant legislation) to demonstrate how they will comply by providing a design proposal or an assessment of the risk. This must be supported with appropriate evidence from a competent person and a risk assessment.

What the guidance covers 

The document is structured into five main sections, each addressing specific aspects:

1. Background information on EV fire hazards 

This section provides an overview of the potential fire hazards associated with EVs, offering valuable context for understanding the safety measures discussed in the guidelines.

Potential hazards may relate to:

• Thermal runaway
• Battery Management System (BMS) failure
• Factors leading to battery fires (i.e. thermal, electrical, and mechanical abuse)
• Fire growth rate and pattern
• Firefighting of EV fires (e.g. large quantities of water are required to extinguish an EV fire)
• Frequency and likelihood of fires involving EVs vs ICEVs (internal combustion engine vehicle)
• Ecological considerations (i.e. firefighting water run-off)

2. Common fire safety features of covered car parks and reported fire safety issues 

Here, the document details the typical fire safety features found in covered car parks. These include:

• Means of escape and warning
• Internal fire spread (linings and structure)
• External fire spread
• Smoke ventilation system
• Firefighting access and facilities

This section then goes on to detail reported fire safety issues in covered car parks, using the December 2017 fire in the Liverpool Echo Arena’s multi-storey car park as one example.

3. Steps to determine relevant mitigation measures 

This section guides readers through the process of identifying the appropriate mitigation measures needed to address fire safety concerns in their specific parking environments.

The recommended steps are:

1. Establishing fire safety objectives and constraints
2. Risk assessment to establish mitigation measures
3. Factors relevant to car parks to be considered when undertaking the assessment
4. Risk assessment process5. Mitigating the risk – ERIC hierarchy of control:

• Eliminate: Remove the hazard completely and prevent it occurring.
• Reduce: Decrease the likelihood of the hazard occurring.
• Isolate: Implement measures so that the effect of the hazard is limited.
• Control: Adopt procedures/measures to manage the consequences when the hazard occurs.

4. Hazard mitigation measures 

This chapter introduces the mitigation measures that can be implemented to either eliminate, reduce, isolate or control the likelihood and impact of a fire resulting from an EV or EVCP.

The measures may relate to any of the hazards outlined in section 1. For example, relating to the thermal abuse of EV batteries, a recommended measure is to provide water-based suppression within the car park. Each risk mitigation measure has been assessed against the ERIC hierarchy of control detailed in the previous section, to assist the car park operator and / or designer in considering the effectiveness of each measure.

5. Discussion of mitigation measures 

Some of the mitigation measures outlined in the guidance require substantial investment and

planning, while others are low impact/low cost. This final section encourages further discussion and exploration of the proposed mitigation measures, fostering a comprehensive understanding of the safety recommendations.

It is important to note that these guidelines have an ‘interim status’ because they are based on the information available at the time of their release. As knowledge of EV fires continues to evolve, the recommended mitigation measures may change accordingly. Therefore, it is crucial to stay updated with the latest developments in EV fire safety, and fire safety on the road.

Furthermore, these guidelines do not substitute existing safety laws or the obligation to adhere to them. Instead, they serve as supplementary guidance to help enhance fire safety measures within covered car parks where electric vehicles are present.