Air emissions & firewater runoff contamination from lithium-ion battery fires in rubbish trucks.

The increasing presence of lithium-ion (Li-ion) batteries in municipal waste streams poses growing challenges for safe waste management. This study aimed to characterise airborne emissions and firewater runoff contaminants generated during battery fire suppression activities. Controlled fire trials were conducted at a specialised facility using a rubbish truck filled with representative waste and various Li-ion batteries (3.7-40 V). Airborne emissions were sampled before and after extinguishment at multiple locations, and firewater runoff was collected following suppression activities. The results revealed that Li-ion battery combustion releases a complex mixture of toxic gases and chemical byproducts. Hydrogen fluoride (HF) peak concentrations reached 17.2 mg/m3, with fluoride ranging between 5.2 and 13.3 mg/m3. Hydrogen cyanide (HCN) was detected up to 2.05 ppm before extinguishment but was undetectable post-suppression. Carbon monoxide (CO) peaked at 1658 ppm, and sulphur dioxide (SO2) at 38.1 ppm, exceeding occupational exposure limits by over 30-fold and 7-fold, respectively. Acetaldehyde levels were especially elevated (55.04 mg/m3). Fluoride concentrations reached 6 mg/L (Trial 4), exceeding the freshwater ecosystem protection guideline of 1.7 mg/L. Metal concentrations also surpassed environmental trigger values: aluminium (2.48 mg/L), copper (2.38 mg/L), manganese (3.76 mg/L), and nickel (2.56 mg/L), all well above ANZECC/ARMCANZ freshwater thresholds. The findings underscore the substantial human health risks and ecological hazards of Li-ion battery combustion in municipal waste. Emissions and runoff frequently exceeded regulatory safety limits, necessitating improved containment, real-time air monitoring, specialised suppression protocols, and regulatory frameworks to limit exposure during such incidents.