Application for the Reassessment of a Hazardous Substance under ...

Ecotoxicity mixture calculationsSubclass 9.1 – Aquatic Ecotoxicity - Summation method1.4 Apply summation method for classification of mixtures for aquatic ecotoxicity (referERMA New Zealand User Guide to HSNO Thresholds and Classifications, Part VI,Chapter 19, page 20):Level 1: 9.1A x MIf ≥25%, then 9.1ALevel 2:Level 3:(M x 10 x 9.1A) + 9.1BIf ≥25%, then 9.1B*(M x 100 x 9.1A) + (10 x 9.1B) + 9.1CIf ≥25%, then 9.1C*Level 4: 9.1A + 9.1B + 9.1C + 9.1DIf ≥25%, then 9.1D* If a mixture is classified as 9.1B or 9.1C and the weighted sum of components that are notrapidly degradable or are bioaccumulative is < 25% then the mixture is assigned theclassification at the step below, ie 9.1B reduces to 9.1C, and 9.1C to 9.1D.Level 1:< ≥ 25% NOT 9.1ALevel 2:< ≥25% NOT 9.1BLevel 3:< ≥25% NOT 9.1CLevel 4:< ≥25% NOT 9.1DSubclass 9.2 – Soil Ecotoxicity - Summation method1.5 Apply summation method for classification of mixtures for soil ecotoxicity (referERMA New Zealand User Guide to HSNO Thresholds and Classifications, Part VI,Chapter 20, Page 10):Level 1:9.2A x M If ≥25%, then 9.2ALevel 2:(M x 10 x 9.2A) + 9.2BIf ≥25%, then 9.2BLevel 3:(M x 100 x 9.2A) + (10 x 9.2B) + 9.2CIf ≥25%, then 9.2C*Level 4:9.2A + 9.2B + 9.2C + 9.2DIf ≥25%, then 9.2D* unless the weighted sum of components with DT >30 days (or no data on degradation) is