The Government of Canada has issued a Notice of Intent to Amend the Prohibition of Certain Toxic Substances Regulations to further restrict the manufacture, use, sale, offer for sale and import of three oil and water repellents (PFOS, PFOA and LC-PFCA) as they constitute a danger to the environment and Canada's endangered whale species. Per- and polyfluoroalkyl substances (PFAS) and Perfluorooctanoate (PFOA) are used in some AFFF foams and this NOI indicates it is just a matter of time before all PFOS and PFOA are completely banned from use due to their toxicity. Therefore, industry needs to adopt alternative products that are less harmful to the users and the environment.
The industry buzz seems to be that Short-Chain PFAS (C6) containing products are the answer. However, research is showing these formulations are less effective for Class B fire extinguishment and burn-back resistance. These Short-Chain PFAS compounds are also environmentally persistent and easily distributed through biological pathways.
FireRein has alternatives which are truly benign and nontoxic. Eco-Gel™ is the only surfactant free firefighting water additive effective for extinguishing Class B fires. Eco-Gel™ is certified as 100% bio-based. Eco-Gel™ is non-toxic and biodegradable.
FireRein has provided these technical comments in relation to the Notice of Intent:
What is PFOA and how is it used for firefighting?
Per- and polyfluoroalkyl substances (PFAS) are a group of compounds used in a variety of products, such as textiles, coatings, firefighting foams, and many others. Perfluorooctanoate (PFOA) is a chemical placed within the PFAS chemical group. PFOA is used in some aqueous film forming foam (AFFF) and acts as surfactants to improve the effectiveness of fire and vapor suppression for Class B, hydrocarbon fuel fires. Long-chain PFOA consist of a hydrophobic carbon-fluorine tail group with seven or more carbons, and a hydrophilic carboxylic acid end group. The hydrophilic end group allows the PFOA containing foam concentrate to mix with fire suppression water to generate the AFFF. As the hydrophobic tail of PFOA reduces the surface tension between water and non-polar solvents, the AFFF can effectively coat a pool of hydrocarbon fuel and act as a thermal and evaporation barrier, eventually extinguishing combustion. However, the chemical properties that make PFOA effective for fire suppression can lead to wide distribution in the environment.
Toxicity
There is significant data available on the impact of (sub)chronic PFOA exposure on reproductive and/or developmental and other types of effects in both humans and animals(1,2). However, the results from epidemiological studies are not always consistent(1,2). The available epidemiology studies suggest associations between perfluoroalkyl exposure and several human health outcomes, such as pregnancy-induced hypertension/pre-eclampsia, liver damage, increased risk of thyroid disease, and increased risk of decreased fertility(1). Animal studies show mainly effects from PFOA on the liver, the gastrointestinal tract and on thyroid hormone levels(2). Carcinogenic effects of PFOA have also been studied (human and animal studies). Several authorities, including ATSDR, U.S. EPA and IARC do not classify PFOS and PFOA as “proven carcinogens”, but instead as “suggestive carcinogens” or “possibly carcinogenic to humans” because of existing uncertainties(1,3,4).
Environmental fate and behaviour - relation to firefighting activities
As PFOA has both hydrophobic and hydrophilic properties, partitioning, transport, and transformation occur across multiple media types when released into the environment. PFOA is persistent in the environment, bioaccumulative, and toxic(1,5). PFOA is widely distributed in the global environment due to its high solubility in water, low/moderate sorption to soils and sediments and resistance to biological and chemical degradation(2). One of the major sources of PFOA in the environment is from fire training areas and fire response sites through the use of AFFF. The potential of environmental contamination from AFFF use during training exercises is high, as training facility infrastructure typically does not focus on containment(6). Additionally, during fire suppression activities in emergency situations, AFFF containment is not top priority. For example, the use of 45,000L of AFFF on a fire at the Lester B. Pearson International (Toronto) Airport, Canada, resulting in the downstream contamination of surface water and fish(7).
Source-pathway-receptor linkage to the Southern Resident Killer Whale and the Saint Lawrence Estuary Beluga whale populations
PFOA is identified as a Persistent Organic Pollutant (POP). A POP is defined as global toxic contaminants found ‘distant from sources’ for long periods and accumulate in the fat of humans and free-ranging mammals. However, contrary to other POPs, PFAS compounds have a low affinity to lipids, but bind to proteins(2). Nevertheless, in order to promote the growth of the population and support recovery of these species, reduction in the discharge of POPs, such as PFOA, needs to continue. However, as AFFF containment is not a priority during fire suppression activities, the release of PFOA containing AFFF into surface waters, ground water, air, and soil is inevitable during emergency situations.
Short Chained Short-chain perfluoroalkyl acids as an alternative
Short-chain PFASs are defined as having a chain length with less than 7 carbons. These PFASs are widely used as alternatives for long-chain PFASs, however they have other properties of concern. Short-chain PFASs have higher mobility in soil and water, as sorption and retardation generally decreases with decreasing chain length(8). As final degradation products of short-chained PFASs are also extremely persistent, there is a faster distribution of short-chain PFASs to water resources compared to long-chain PFASs, which increases exposure potential and complicates remediation efforts(8). This is evident, as shortchain PFASs are already widely distributed throughout the environment, including remote regions(8). Although short-chain PFASs are assumed to have a lower bioaccumulation potential, greater potential for exposure makes it difficult to estimate long-term adverse effects(8). Therefore, it is not responsible to use short-chain PFASs as “safe” alternatives without evaluating the consequences. Additionally, due to the higher aqueous solubility, short-chain AFFF formulations are less efficient at forming a thermal and evaporation barrier on a pool of hydrocarbon fuel.
Reference List
(1) (ATSDR), A. for T. S. and D. R. Toxicological profile for Perfluoroalkyls. (Draft for Public Comment). Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service.; 2018.
(2) Smith Beuthe M Dunk S Demeure JMM Carmona A Medve MJ Spence, J. B. Environmental fate and effects of poly-and perfluoroalkyl substances (PFAS) Prepared for the Concawe Soil and Groundwater Taskforce (STF/33); 2016.
(3) (IARC), I. A. for R. on C. Agents Classified by the IARC Monographs, Volumes 1-123 CAS No. Agent 0 B 0 B 0 B Group Volume Year; 2017.
(4) Environmental Protection Agency, U. Drinking Water Health Advisory for Perfluorooctanoic Acid (PFOA)-Drinking Water Health Advisory for Perfluorooctanoic Acid (PFOA); 2016.
(5) Vierke, L.; Staude, C.; Biegel-Engler, A.; Drost, W.; Schulte, C. Perfluorooctanoic acid (PFOA) — main concerns and regulatory developments in Europe from an environmental point of view. Environ. Sci. Eur. 2012, 24 (1), 16 DOI: 10.1186/2190-4715-24-16.
(6) Milley, S. A.; Koch, I.; Fortin, P.; Archer, J.; Reynolds, D.; Weber, K. P. Estimating the number of airports potentially contaminated with perfluoroalkyl and polyfluoroalkyl substances from aqueous film forming foam: A Canadian example. J. Environ. Manage. 2018, 222, 122–131 DOI: 10.1016/J.JENVMAN.2018.05.028.
(7) de Solla, S. R.; De Silva, A. O.; Letcher, R. J. Highly elevated levels of perfluorooctane sulfonate and other perfluorinated acids found in biota and surface water downstream of an international airport, Hamilton, Ontario, Canada. Environ. Int. 2012, 39 (1), 19–26 DOI: 10.1016/J.ENVINT.2011.09.011.
(8) Brendel, S.; Fetter, É.; Staude, C.; Vierke, L.; Biegel-Engler, A. Short-chain perfluoroalkyl acids: environmental concerns and a regulatory strategy under REACH. DOI: 10.1186/s12302-018-0134-4.