Last issue, Part 1 of this article covered a range of issues with Queensland’s (QLD) recent foam policy, while also complementing it for taking action on PFOS and PFOA. We reviewed other important considerations of the fire, like smoke and breakdown products which enter firewater run-off, the impact of these harmful ingredients on firefighter’s health, and the 3 main alternatives to banned long-chain C8 fluorochemicals. Is it better to let it burn?
Maybe the use of Fluorine Free Foams (F3) is a better idea in places, but these are fraught with significant fire performance weaknesses we summarized, including lack of fuel repelling ability, poor vapour sealing, slower control and extinction, often with
sudden, unpredictable flare ups and flashovers, that can result in greater escalation risks and re-involvement. More damage is likely to result, particularly from larger events, and the ever-present increased life safety risks, increased firewater runoff, and typically 10-30 times higher aquatic toxicity than AFFFs, cannot be ignored.
Research shows when F3 and AFFF foams are mixed with gasoline and exposed to an ignition source above the foam blanket, the F3 sustains ignition immediately, while the AFFF resists ignition, even after 10 minutes – caused by fuel contamination of F3 without fuel shedding additives. QLD’s foam policy embraces F3 agents, to avoid “any potential problems” associated with fluorochemicals. Yet a leading ICAO Level B certified F3 fire demonstration at 32°C had to be aborted because “too many environmental factors were not under our control to do F3”. It was replaced by C6 AFFF which worked well. When much of Australia including QLD experiences over 32°C for significant parts of the year… How safe are we as passengers when 26 major Australian airports are using F3?
This policy overlooks Fire Services responding to Major Hazard Facility (MHF) fires generally use the foam on site, which to date is mostly fluorinated agents like FluoroProteins, AFFFs and AR-AFFFs/AR-FFFPs which work very effectively.
Growing evidence suggests F3s cannot provide the same levels of speed, efficiency, effectiveness or reliability on large volatile fuel fires like gasoline, ethanol or crude oil. ALL fluorinated foams – not just PFOS, require incineration in QLD, as well as any persistent chemicals/contaminated firewater runoff which also qualify as regulated waste for incineration, when exceeding exceptionally low trigger values of 0.3ppb each for PFOS/PFOA, and 1ppb for Total Oxidisable Precursor (TOP) assay of C4-C14 fluorochemicals (0.3ppb equates to 1second in 100 years).
Irrespective of whether C6, F3 or no foam is used in most incidents, there is likely to be residual contamination from that 95% of other fluorochemical sources considered ubiquitous, particularly with structural and vehicle fires, that are predominantly disposed of through Waste Water Treatment Plants (WWTPs) in QLD, creating two contradictory policy requirements? Presumably this contaminated structural fire run-off from burnt carpets/upholstery etc. is also regulated waste, even where no Class B foams are used?
A focus on firefighting foam’s environmental impacts alone is misleading…when the whole fire incident’s environmental impacts and other fluorochemical sources are not being adequately considered. How can Is this QLD policy be delivering lowest environmental impacts?
C6 short-chain fluorosurfactants are different
Research shows clear differences between PBT (Persistent, Bioaccumulative, Toxic) legacy PFOS/PFOA based fluorochemicals and environmentally more benign C6 short-chain fluorosurfactants. Although still Persistent, increasing scientific research confirms that C6 fluorosurfactants are:
- not considered Bioaccumulative,
- not shown to be carcinogenic, nor mutagenic, nor developmental nor reproductive toxicants. They also exhibit LOW Toxicity to aquatic organisms and mammals, including humans, and it has not been shown harmful to human health.
- C6 fluorosurfactants cannot qualify for POP listing, since at least 2 of 4 critical conditions are NOT Met.
- NICNAS in its IMAP 2016 Human Health Tier II C6 Assessment’s Occupational and Public Risk Characterisations, concluded: “The chemicals are not considered to pose an unreasonable risk to workers’ health.” and ”… the public risk from direct use of these chemicals is not considered to be unreasonable.”
Clearly C6 Fluorotelomer surfactants do not use any long-chain C8 ingredients and cannot breakdown to PFOS or PFOA. Its main potential breakdown product is C6 PerFluoroHexanoic Acid (PFHxA), and some 5:3 Acid. The tiny PFOA unavoidable by-product of manufacture trace is a few ppb – accepted by US EPA, exempted by REACH, and well below proposed EU draft regulatory restriction levels.
PFHxA has been extensively tested, confirming that equivalent % of C6 to C8 achieves equivalent US MilF Spec fire performance.
Consequently US Airforce recently invested $6million+ in C6 AFFFs. Short-chain PFHxA is excreted through human kidneys with a half-life in humans averaging 32 days. Very different from average C8 human half-lives: of PFOS typically 5.4 yrs; PFHxS 8.5 yrs; and PFOA 3.5 yrs. Global regulatory bodies including US EPA, UK Environment Agency, ECHA, REACH and NICNAS have reviewed and assessed these purity compliant C6 fluorochemicals as acceptable for use, avoiding the fundamental drawbacks of PFOS/PFOA, plus undesirable life safety drawbacks of alternative F3 agents, when QLD’s policy fully accepts life safety is paramount.
C6 v F3 performance comparisons
Recent fire test comparisons from over 80 fire tests involving 5 different F3 agents and 5 fluorinated AFFF agents, 3 of which are C6 (1,3&4 in Fig.2) provide surprising results. F3s were 50% slower on Jet A1 and 60% slower on gasoline than AFFFs. 80 second F3 fire control compared to 30seconds for AFFFs. AFFFs delivered more versatility, resilience, reliability on wider fuel range, and these differences widened as application rates were lowered.
2008 research at Newcastle University clearly identified that “…best F3 provides only 30% durability of AFFF on gasoline”, was reinforced by a 2013 Caltex gasoline spill incident at Banksmeadow Sydney, where a valve leaked 130,000 litres of gasoline leaked into a bund. Vapours suppressed for only 15-20 minutes by F3 compared to 90 minutes when FluoroProtein was used – 4.5 times longer, using minimal resources. UK Environment Agency advises “the primary concern should be which foam is the most effective at putting out the fire. All firewater runoff and all foams present a pollution hazard.” This approach ensures life safety, reduces escalation, protects communities, reduces run-off and delivers minimized environmental impacts.
Figs 3&4 conveniently summarise key advantages we seek regarding fire and environmental performances, “categorising” key criteria against both alternative foam types.
C6 agents resist flammability and breakdown of the foam blanket, while also reducing emulsification with the fuel, that could carry fuel past oil separators. F3s generally do not.
Environmentally, reducing smoke and breakdown products from the fire is critical. As is protecting life safety from sudden flare-ups and re-involvement, while also minimising use of foam and water resources, plus minimizing aquatic toxicity. These exceed QLD’s current focus on foam agent impacts alone by focusing on life safety.
Navigating this minefield…
The whole fire incident deserves a more holistic approach to navigate this minefield most effectively.
Assessing risks, exposures and liabilities; identifying critical factors and life safety issues are vital to achieving meaningful answers; since all foams whether fluorinated or fluorine free, plus resulting firewater runoff, pollute.
Avoiding misleading assumptions, and incorrect interpretations, seeking weaknesses as well as strengths of potential alternatives are critical elements we expect to be addressed.
6 key objectives should form the basis of our for selection, to deliver necessary success:
- protecting people and communities
- minimising risks, liabilities, exposures
- delivering strongest fire performance
- protecting valuable assets
- providing containment and waste treatment options
- so that environmental responsibility is delivered
Most agree PFOS, PFOA and PFHxS are undesirable legacy issues we need to manage and transition away from. Most accept all foam types can pollute, whether fluorinated or not, or just firewater runoff alone. Fast fire control and minimal use of resources helps reduce adverse environmental impacts of the whole incident. Why does QLDs policy fail to recognize and reflect these critical factors?
Unpredictable flashbacks, escalation, increased life safety risks, high aquatic toxicity, more fuel emulsification from strong detergents (hydrocarbon surfactants) in separators seem characteristic of F3s.
Fuel repellency and foam spreading are critical C6 fluorsurfactant foam advantages, most regulators consider neither B nor T, nor harmful to human health, nor particularly hazardous to receiving environments. Careful risk assessment of whole potential incidents and how they evolve, is critical to ensuring life safety, minimizing risk, liabilities, exposures AND minimised environmental impacts, facilitating best choices.
Wide acceptance that all foams have drawbacks, none are perfect, but the present generation of C6 short-chain foam agents are acceptable to the world (outside QLD) and probably deliver the most efficient, reliable and environmentally benign overall choices for future effective volatile flammable liquid fire control. There now seems sufficient scientific information to support the continued use of C6 fluorinated firefighting agents, capable of delivering the best (or least worst!) all round community safety and environmentally more responsible answers to these complex problems.
For more information, email [email protected]