Here are some points that Fire Rescue Victoria is asking the industry to consider in relation to the Hazard Assessment of the impact of Electric Vehicles in Buildings.
AFAC & FRV consider that EVs, EV charging and onsite battery storage systems are a special hazard under BCA DtS Provisions E1.10 and E2.3, thereby requiring additional fire safety provisions to address the special hazards relating to firefighting and smoke management. FRV emphasises that it is the design team’s responsibility to review and address all potential fire loads and risks; this includes electric vehicles (both parking and charging) as well as any proposed onsite battery storage systems.
Fires associated with this type of equipment in particular lithium battery systems may potentially have higher outputs of flammable gas, smoke and heat, may potentially burn for considerably longer periods and may require significantly more water to extinguish the fire, protect nearby exposures and reduce instances of re-ignition. Designers should conduct their own research on these matters; information relied upon should be current and published by reputable sources. The alternative solutions should consider the impacts of electric vehicles, charging stations and battery storage on occupant safety and fire brigade intervention i.e. electrical safety and operation of sprinklers/hydrants etc.
The Fire Engineering Report (FER) should detail and asses both proposed EV charging stations and battery storage areas as well as future proposed areas if known. This may result in the requirement for additional fire safety provisions above DtS to address the special hazards; such additional provisions may include;
- Enhanced Ventilation. An enhanced ventilation system may be required because of the potential higher outputs of smoke and heat; in addition before catching fire a battery that is failing may produce a flammable toxic gas cloud.
- Enhanced Sprinkler Protection. Sprinklers are unlikely to extinguish/control a fire in the electric battery itself; therefore enhanced sprinkler protection and fast response heads may be required to contain a fire and protect the surrounding building structure and other exposures.
- Enhanced Water Supply. An enhanced water supply may be required due to the fact that potential fire loads may potentially burn for considerably longer periods and may require significantly more water to extinguish the fire, protect nearby exposures and reduce instances of re-ignition.
- Enhanced Fire Ratings. Enhanced Fire Ratings may be required due to the difficulty in extinguishment and risk of re-ignition.
- Additional Access Provisions. Additional fire-fighter access provisions may be required to assist in fire-fighter intervention.
- Mechanisms for Equipment Removal. Mechanisms for equipment removal should be considered; once a battery storage unit has been compromised by fire there is a risk of re-ignition that may last up to 5 days after the event. The design team should consider that in the event of a fire how will the EV or battery storage system be safely removed from the building once the fire has been initially extinguished.
In addition to the above; last year the ABCB published the following document ‘Summary of changes… NCC 2022 public comment draft (stage 2)” (see attached). On page 21 of this document the ABCB state the following;
“ABCB Investigation has found that based on the available evidence (see report: Hazard Assessment of the impact of Electric Vehicles, available on request), the risk profile of a car park filled with 100% EV is equivalent to a carpark filled with 100% of conventional vehicles. On this basis no changes to existing fire safety provisions are proposed for carparks at this time”
The ABCB developed this position despite the following findings of their own report (see ‘Hazard Assessment of the impact of Electric Vehicles’ also attached);
EV Fire Severity:
- EV and ICEV are substantially similar in terms of the nature and amounts of combustible materials, and fire tests mostly show similar heat release rates and fire behaviours.
- The theoretical fire load of an EV battery is broadly similar to an ICEV fuel tank, but the plastics used for battery casings and packaging add substantially to that.
- EV fire testing to date has been limited, and full-scale tests on new models with larger batteries are needed to establish their maximum fire potential with confidence.
- EV battery fires can produce torch flames or fireballs, so more rapid-fire spread to adjacent cars is expected, but this also needs to be investigated in full-scale tests.
- EV battery deflagration events may happen, but unconfined vapour cloud explosions are considered very unlikely.
EV Firefighting:
- Distinct aspects of EV carpark fires have implications for firefighting intervention and smoke control.
- EV fires produce significantly more smoke and toxic gases than ICEV, with hydrogen fluoride being a concern for firefighters tackling an EV fire in closed or underground carparks.
- EV battery fires need several hours or days of firewater cooling for control and extinguishment.
- Long duration fire intervention requires suitable and sufficient firewater supplies and firewater runoff control arrangements.
Sprinkler Protection:
- Automatic sprinkler protection should be considered for all carparks with EVSE facilities.
Firefighting:
- Smoke control for closed or underground carparks must provide an adequate air change rate to limit HF toxic gas concentrations.
- Firewater supplies must be adequate to supply cooling hose streams for (potentially) several days.
- Firewater drainage capacity and runoff control arrangements must be adequate for such extended fireground operations.
Disclaimer: Please note the above statements are reproduced from FRV’s email to the stakeholders. If your building project involves electric vehicle fire safety matters, please discuss about the above requirements with the project fire safety engineer for advice. Should you need further information, please get in touch with me via Rusthi@PassionateFE.com