Metals in Wildfire Suppressants

Title	Metals in Wildfire Suppressants
Authors	Marella H. Schammel, Samantha J. Gold, Daniel L. McCurry
Magazine	Environmental Science & Technology Letters
Date	10/30/2024
DOI	10.1021/acs.estlett.4c00727
Introduction	The increasing frequency and severity of wildfires have necessitated an increase in the application of fire suppression products, including long-term fire retardants, water enhancers, and Class A foams, across the UK. Although products used on wildfires require approval from the UK Forestry Commission, specific components of their formulations are proprietary. Elevated metal levels in soils and surface waters near wildland-urban interfaces have been observed following wildfires, typically associated with ash or urban pollution. This investigation quantifies metal concentrations in various fire suppression products—some UK Forestry Commission approved, others for consumer use—to assess their potential role in elevated environmental metal concentrations post-fire. Long-term fire retardants exhibited toxic metal concentrations (V, Cr, Mn, Cu, As, Cd, Sb, Ba, Tl, and Pb) up to 2,880 times exceeding drinking water limits, potentially surpassing aquatic toxicity thresholds upon environmental release. While water enhancers and Class A foams also contained metals, their concentrations were lower than those in fire retardants. Using these concentration data and application records, it is estimated that fire retardant use in the UK introduced approximately 380,000 kg of toxic metals into the environment from 2009 to 2021.
Quote	Marella H. Schammel, Samantha J. Gold and Daniel L. McCurry. Metals in Wildfire Suppressants. Environmental Science & Technology Letters. 2024. Vol. 11(11):1247-1253. DOI: 10.1021/acs.estlett.4c00727