Zinc Chelate Complex

Endpoint summary

Description of key information

Acute toxicity to Daphnia Magna:

The acute toxicity of the test item to Daphnia magna was determined in a 48‑hour test according to the OECD Guideline for Testing of Chemicals, No. 202 (2004) and the Commission Regulation (EC) No. 440/2008, Part C.2. The test item is a sparingly soluble substance, which hydrolyses in aqueous solutions resulting in an organic degradation product and copper. Therefore, Water Accommodated Fractions (WAFs) with the loading rates of 0.32, 1.0, 3.2, 10 and 32 mg/L were tested to assess the toxicity of the test item to daphnids. The test was performed using glass tubes completely filled (without headspace) with test medium that were tightly sealed with glass stoppers to avoid possible losses of volatile components of the test item by evaporation (closed system).

A semi-static test design with a test medium renewal after 24 hours was used. For preparation of the WAFs, individual dispersions of the test item with the loading rates of 3.2, 10 and 32 mg/L were prepared. The dispersions were intensively stirred for 3 hours to dissolve a maximum amount of the test item in the dispersions. After stirring, each of the dispersions was filtered through a membrane filter (0.45 µm).These resulting undiluted filtrates were tested as WAFs.The preparation of the test media was based on the OECD Guidance Document No. 23 (Second Edition) on Aquatic Toxicity Testing of Difficult Substances and Mixtures, 2019.

The biological results are expressed based on loading rates, since the test item isa sparingly soluble compound, which hydrolyses immediately after being applied to aqueous solutions, forming an organic degradation product and copper.The EL50 (48h) on Daphnia Magna was found to be 5.9 mg/L based on loading rate.

Algal growth inhibition:

The impact of the test item on the growth of the freshwater green algal species Pseudokirchneriella subcapitata was investigated in a 72-hour static test according to the OECD Guideline 201 (2006, corrected 2011) and the Commission Regulation (EU) No 2016/266, C.3. The substance is a sparingly soluble substance, which hydrolyses in aqueous solutions resulting in an organic degradation product and copper. Therefore, Water Accommodated Fractions (WAFs) with the loading rates of 0.10, 0.32, 1.0 and 3.2 mg/L were tested to assess the toxicity of the test item to algae. As a precaution, the test was performed using glass Erlenmeyer flasks completely filled (without headspace) with test medium that were tightly sealed with glass stoppers to avoid potential losses of test item by evaporation (closed system).

A static test was performed. For preparation of the WAFs a dispersion of the test item with the loading rate of 3.2 mg/L and 10 mg/l was prepared. The dispersion was intensively stirred for 3 hours at room temperature in the dark to dissolve a maximum amount of the test item in the dispersion. After stirring the dispersion was filtered through a pre-conditioned membrane filter (0.45 μm). The resulting undiluted filtrate was tested as a WAF. The preparation of the test media was based on the OECD Guidance Document No. 23 (Second Edition) on Aquatic Toxicity Testing of Difficult Substances and Mixtures, 2019.

The biological results are expressed based on loading rates, since the test item isa sparingly soluble compound, which hydrolyses immediately after being applied to aqueous solutions, forming an organic degradation product and copper.The EL10 (72h) on Green Algae was found to be 0.36 mg/L based on loading rate.