Environmental selection and use of firefighting foams
The Australian fire protection industry has concerns with some regulatory approaches to firefighting foams, and calls for modifications.
Firefighting foam is a suppression agent used for controlling and extinguishing fires involving flammable liquids.
Recently there has been an increased focus on environmental effects of the use of firefighting foam, often without due consideration for other important issues such as firefighting performance, firefighter safety and system compatibility.
Whilst the intention of regulatory responses to improve environmental outcomes is to be praised, careful consideration of the firefighting implications is needed to avoid serious shortcomings that may undermine the aim of reducing environmental impacts and could adversely affect fire safety, especially in major hazard facilities, where fire fighting performance is critical.
It’s hoped that by way of this article, the concerns the fire protection industry has with some regulatory approaches will be more widely appreciated and that this will lead to more balanced responses that achieve improvements to both environmental and fire safety outcomes.
Points of agreement
There is widespread agreement within the fire protection industry on a number of key issues relating to the environmental impacts of foams, including:
- Acknowledgement that all firefighting foams have adverse environmental impacts.
- Support for a ban on all foams containing PFOS and for existing stocks removed from service and destroyed.
- Understanding that all foam and fire water effluent should be managed in an environmentally responsible manner.
- End users should transition away from C8 fluorinated foams, including those that contain PFOA (over a suitable transition period).
FPA Australia wants to see a holistic approach to the risks associated with the use of firefighting foams to fight fires in hazardous facilities.
Fire Industry concerns
Selection decisions on the type of foam to be used for a particular site, application or fuel should not be based solely on the environmental properties of firefighting foam concentrate.
Firefighting performance is equally important in determining the environmental outcomes for an incident (e.g. duration, toxic combustion products and volume of fire water effluent produced), as well as business continuity and safety of firefighters, hazardous facilities and the community in general.
Choosing the best firefighting foam for an application must, first and foremost, be based on selecting the best product to protect people, property and the environment. This requires selection based on a balance of firefighting performance, reliability and life safety, with minimal toxicological and environmental effects. The following criteria should all be fully considered as part of any firefighting foam selection process:
- firefighting performance, specifically on the fuels and in the applications in question
- life safety
- physical properties and suitability for use in existing equipment and systems
- compatibility with system design and third party approvals
- environmental impacts of the foam itself and from fire water effluent more generally.
Although environmental performance is important, failure to adequately consider the firefighting and system performance aspects may result in selection of a foam that is completely ineffective for use in the system and/or on the fuel in question.
Selection of a foam which is unsuitable for the hazard to be protected can lead to greater environmental impacts as a result of longer extinguishment times, use of larger quantities of foam and water and the production of significantly greater quantities of firewater effluent.
Firefighting foam is one component part of a system and changing any component in a system requires a careful evaluation of what impact that change will have on the system as a whole. Evidence of suitability (third party certification) must be provided to demonstrate any foam’s ability to achieve the required firefighting performance for the fuel in question, using appropriate and recognised testing protocols. Evidence of suitability must also be provided to ensure that the foam is compatible with associated systems and equipment. It must be remembered that it is not always possible to change the type of foam used in a system without having to make significant modifications to the system. For example, many foams have high viscosity and may not be able to be correctly proportioned using existing hardware in systems where low-viscosity foams were previously used. Any proposal to change the type of foam used in a system requires careful consideration and must take fire safety and engineering factors into account.
This includes completing a detailed review of the design, performance and operation of the system as a whole. Such design reviews should include consultation with fire system designers, foam and foam hardware suppliers and the relevant regulatory authorities.
FireFighting Foam in use in an emergency spill situation.
No such thing as environmentally friendly foam
Let’s be clear—there is no such thing as environmentally friendly foam. All firefighting foams have adverse effects on the environment. However, it must also be recognised that fires—especially those involving flammable liquids and other chemicals—also have significant adverse environmental effects in their own right. To minimize environmental impacts, it is a generally accepted objective to extinguish a fire as quickly as possible.
In achieving this objective there is a positive effect in terms of minimising risk to life safety, property, the environment and business interruption. Specifically, using the minimum possible quantity of foam and water to control or extinguish the fire is greatly beneficial because it reduces the amount of fire water effluent to be managed post incident. Good firefighting performance is critical to good environmental outcomes and, as a result, firefighting performance cannot be ignored when making selection decisions aimed at minimising environmental impact. Poor firefighting performance results in poor environmental outcomes because of:
- longer extinguishment times—risk of escalation, more toxic combustion products, risk to life, property and business continuity
- use of larger quantities of foam and water—more toxic and contaminated effluent produced
- life safety concerns—e.g. slow knockdown, poor flashback resistance, unreliable post-fire securement and risk of escalation.
Not all foams are equal
Firefighting foams have different firefighting performance. Effective firefighting foams must:
- be compatible with the foam proportioning and delivery equipment
- cool the fuel surface
- protect the fuel from re-ignition
- resist attack or breakdown by the fuels (in particular, polar solvents)
- resist mixing with the fuel
- spread rapidly over the fuel surface
- suppress the release of flammable vapours.
Significantly, firefighting foams containing fluorinated surfactants have valuable firefighting performance characteristics that historically have been unmatched by F3. These performance advantages, which include improved firefighter safety and increased firefighting effectiveness (vapour suppression, knockdown and burnback), can significantly reduce the amount of foam required to control an incident and limit damage to the environment and risk to life and property.
That said, the performance of some F3 has and continues to improve with a few having recently achieved compliance with the relevant Australian Standards for use in portable fire extinguishers and pre-engineered vehicle systems.
Less post-fire effluent
Better firefighting performance means less post-fire effluent. These performance differences are not limited to small-scale fire tests. An incident at Caltex’s Banksmeadow terminal in Sydney in July 2013 provides a real-world example of
the significant performance difference between F3 and fluorinated foams. Foam was used for vapour suppression and to prevent ignition of a large 175,000-litre fuel spill. When using F3, effective vapour suppression (maintaining vapour levels below the fuel’s lower explosive limit) was only achieved for 15–20 minutes before foam needed to be re-applied. However, when fluoroprotein foam was later used, vapour suppression was achieved for 90 minutes.
This example demonstrates that use of fluorinated foam can provide significantly longer protection and reduced frequency of re-application. It also serves to demonstrate that using a foam with superior firefighting performance can significantly reduce the amount of foam and fire water effluent that needs to be managed post incident.
No silver bullet
Fluorine-free foams do not provide a ‘silver bullet’ solution to environmental problems associated with the use of firefighting foam. As demonstrated above, using F3 in some fire incidents could require significantly larger quantities— three or more times the amount—of both foam and water to manage an incident because the firefighting performance is, in many circumstances, inferior to fluorinated foams. In some specific applications, such as sub-surface foam systems on bulk fuel storage tanks, F3 foams remain completely unsuitable due to their inability to “fuel shed”. Use of a C6 fluorinated foam in sub-surface foam systems is the only environmentally responsible option, short of replacing the system completely, when moving away from the use of a C8 foam in this type of system.
Poor firefighting performance equals increased risk.
Hazardous facility managers need the flexibility to use risk management principles to select the most appropriate foam to manage the particular risks.
The risk management for these facilities must be considered holistically, from pre to post incident, and not be based solely on the environmental properties of the foam concentrate.
Pre-existing site contamination
Using F3 will not eliminate existing site PFAS contamination (or any contamination resulting from other hazardous material for that matter). PFAS compounds can remain present many years after changing to F3. The experience at AirServices Australia sites demonstrates this situation.
AirServices Australia sites changed to many years ago; however, soil and groundwater at these sites was found to be still contaminated by PFOS over five years later.
Fire water effluent from incidents at virtually any industrial site will contain many types of regulated contaminants including hydrocarbons, volatile organic compounds, known carcinogens etc. to name just a few. For this reason, all fire water effluent should be considered contaminated, until testing proves otherwise. Testing of fire water effluent is essential prior to determining the most appropriate method of treatment and disposal in accordance with local regulatory requirements.
In light of the above, environmental regulatory approaches should focus on stipulating how firewater effluent from an incident should be managed based, not on the type of firefighting foam used, but rather on the contamination found in the effluent. The mantra for the management of all firewater effluent should be—contain (the effluent), test (for contaminants), treat (according to the contaminants found).
Risk must be managed holistically
The environmental risks resulting from fires in hazardous facilities must be managed holistically. Environmental regulators must acknowledge that different foam technologies have different firefighting performance characteristics and these can significantly affect the environmental outcome of an incident.
Foam users should be allowed to select the foam to best manage their risk, an approach adopted by the UK Environmental Protection Agency. The UK EPA allows emergency services and hazardous facility managers to select and use the most appropriate foam concentrate to best manage the risk (putting out the fire as quickly and efficiently as possible—fewer combustion products, increased safety, less foam and water usage and less effluent to manage afterwards) with an understanding that the resulting effluent will be treated and disposed of appropriately and in accordance with local environmental regulations.
It is recommended that Australian regulators adopt a similar approach.
Additionally regulators should engage in open and frank discussions with key fire industry stakeholders to ensure any proposed regulatory measures are fully considered and are compatible with life and fire safety objectives. Regulators should not base post-fire effluent treatment decisions purely on the type
of foam concentrate used. All firewater effluent should be considered to be contaminated regardless of the type of foam used (unless on-site testing proves otherwise).
Finally, industry must be allowed sufficient time to transition from existing stocks of C8 foam to either C6 formulations or F3 as appropriate to the particular facility and application.
FPA Australia has published an information bulletin covering in detail the issues surrounding the selection and use of firefighting foam. Copies are available at: http://www.fpaa.com.au/technical/technical-documents/information-bulletins/ib-06-v11-selection-and-use-of-firefighting-foams.aspx
For more information, go to www.fpaa.com.au