In addition to the k-mean clustering we also used the three categories for acute aquatic hazards of the GHS, which were hard set thresholds. The three GHS-based categories for short-term (acute) aquatic hazard are based on thresholds derived from 96h LC50 values for acute fish toxicity: high toxicity (Category Acute 1: 96h LC50 for fish ≤ 1 mg/L), moderate toxicity (Category Acute 2: 1 mg/L < LC50 ≤ 10 mg/L), and low toxicity (Category Acute 3: LC50 > 10 mg/L LC50), Table .1.1 in Reference.