6PPD-quinone (6PPDQ) is a transformation product of 6PPD, a chemical added to tires to prevent cracking and extend tire life. As tires wear on roadways, particles containing 6PPD are released and oxidized, forming 6PPDQ. This contaminant gained significant attention when researchers identified it as the primary cause of urban runoff mortality syndrome in coho salmon, directly linking tire wear pollution to acute aquatic toxicity. Since then, 6PPDQ has been detected in water, soil, airborne particulate matter, and human brain effects are starting to be researched (Invisible Tire Dust Hijacks Alzheimer’s Predictor Genes – Neuroscience News), highlighting its widespread environmental distribution.
Research shows that 6PPDQ is highly toxic to several salmon species, with lethal concentration (LC50) values ranging from 41 to 95 ng/L. Coho salmon are particularly sensitive, often experiencing mortality within hours of exposure. Studies have also demonstrated harmful effects on chinook salmon and rainbow trout, indicating broader ecological risks. In urban watersheds, stormwater runoff can contain 6PPDQ concentrations exceeding toxicity thresholds, making it a priority contaminant for monitoring and regulatory evaluation.
SGS has been a leader in developing and validating ultra-trace analytical methods for 6PPDQ, recognizing early on the need for accurate, defensible data to support environmental monitoring. Using advanced LC-MS/MS techniques, including draft EPA Method 1634, SGS achieves reporting limits as low as 0.1 ng/L in water and 50 pg/g in soils and sediments, well below salmon toxicity thresholds. Prior to the publication of EPA 1634, we noted early research on the high partitioning of 6-PPDQ to soils and sediments and developed robust methods able to analyze high-particulate water, wastewater, biosolids and more. SGS has analyzed samples across Canada and the United States, generating some of the earliest large-scale datasets on 6PPDQ occurrence, including the study that determined the LC-50 of juvenile Coho at 41 ng/L (Lo et al. 2023).
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SGS’s specialty testing service offering supports regulatory compliance, pre‑regulatory monitoring, ecological risk assessment, and mitigation strategy development. With ISO‑accredited laboratories, decades of experience in emerging contaminants, and leadership in method development, SGS provides one of the most comprehensive commercial services available for 6‑PPD‑quinone determination.
Reach out to SGS’s specialty testing experts to learn how we can support a more comprehensive monitoring strategy for 6-PPDQ.