2.2.2. Globally Harmonized System of Classification and Labelling of Chemicals (GHS) -Aquatic toxicity classification

We compiled the acute (H400, H401 and H402 - very toxic, toxic, and harmful to aquatic organisms, respectively) and chronic (H410, H411, H412, and H413 - very toxic, toxic, harmful, maybe harmful to aquatic life with long lasting effects, respectively) aquatic hazard categories per the GHS assessments (eChemPortal OECD, 2020; United Nations, 2019). Chemicals without GHS classification were grouped under “not available”, a category constituting chemicals with insufficient ecotoxicity data for GHS classification as well as those whose toxicity is considered to be insufficient to warrant classification (lethal concentration LC₅₀ or effective concentration EC₅₀ > 100 mg/l) (United Nations, 2019).

In addition to the ecological hazard characterization, we also identified the WP wastewater chemicals included in the EPA’s list of hazardous waste per 40 C.F.R. § 261 (Identification and Listing of Hazardous Waste, 2020).