Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

ErC10 freshwater algae = 22 mg/L

ErC50 freshwater algae = 82.5 mg/L

This information is based on read across to the sodium salt of the corresponding substance.

Key value for chemical safety assessment

EC50 for freshwater algae:
82.5 mg/L
EC10 or NOEC for freshwater algae:
22 mg/L

Additional information

Data are available for the corresponding sodium salt of the substance, docusate sodium. These data are used for read-across to the substance registered.

For the data endpoint “Toxicity to aquatic algae and cyanobacteria” one experimental study rated Klimisch 2 is available. In this study the growth inhibition of formulated product (which contains 64.2% Docusate Sodium) toScenedesmus subspicatiuswas determined in a 72 h static GLP algae growth inhibition test. The test design was based on the EWG 88/302 guideline which is similar to the EEC C.1 guideline. The nominal test concentrations were 0 (control), 10, 17, 30, 50, 90 and 150 mg formulated product/L, corresponding to 0 (control), 6.42, 10.91, 19.26, 32.10, 57.78 and 96.30 mg Docusate Sodium/L. Eight control replicates and 5 replicates from each test solution were set up. Dose verification analysis was not performed, but the substance is considered stable under algae test conditions.

In order to determine the growth of the cultures, the optical density was measured by photometry at 685 nm. The cell density was calculated using a calibration curve (not provided in the report). The cell density was determined at 0, 24, 48 and 72 hours. The growth of the control cultures fulfilled the validity criteria from OECD 201 (2006). The 72 -hour ErC10 and ErC50 are resp. 22 and 82.5 mg Docusate Sodium/L based on the nominal concentration. This study is considered to be acceptable for the risk assessment despite minor shortcomings in the reported documentation. Criticism points are the lack of individual temperature measurement data, the lack of the calibration curve used to calculate the cell density and dose verification analysis was not performed.

The ErC10 and ErC50 of 22 and 82.5 mg Docusate Sodium/L, respectively, are considered to be reliable and will be used for the further risk assessment of Docusate Sodium.