Butyl hydrogen maleate

Short-term toxicity to aquatic invertebrates

Description of key information

The acute toxicity of the test item to the freshwater invertebrate Daphnia magna has been investigated and gave a 48-Hour EC50 value of 91 mg/L with 95% confidence limits of 76 - 108 mg/L. The Lowest Observed Effect Concentration was considered to be 100 mg/L. The No Observed Effect Concentration at 48 hours was 56 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

91 mg/L

Additional information

Introduction

A study was performed to assess the acute toxicity of the test item to Daphnia magna. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (April 2004) No 202, "Daphnia sp., Acute Immobilisation Test" referenced as Method C.2 of Commission Regulation (EC) No. 440/2008.

Methods

Following a preliminary range-finding test, twenty daphnids (4 replicates of 5 animals) were exposed to an aqueous solution of the test item at concentrations of 10, 18, 32, 56 and 100 mg/L for 48 hours at a temperature of 20 °C under static test conditions. The number of immobilized Daphnia were recorded after 24 and 48 hours.

Results

The 48-Hour EC₅₀for the test item to Daphnia magna based on nominal test concentrations was 91 mg/L with 95% confidence limits of 76 - 108 mg/L. The Lowest Observed Effect Concentration was considered to be 100 mg/L. The No Observed Effect Concentration was 56 mg/L.

Analysis of the test preparations at 0 and 48 hours showed measured test concentrations to range from 93% to 94% of nominal value and so the results are based on nominal test concentrations only.