Diisopropyl ether

Toxicity to aquatic algae and cyanobacteria

Description of key information

The substance did not exhibit toxicity to algae when tested according to method OECD 201, with 96-hour EC50 value for cell number greater than 1000 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

1 000 mg/L

EC10 or NOEC for freshwater algae:

1 000 mg/L

Additional information

Acute toxicity to Pseudokirchneriella subcapitata (previously known as Raphidocelis subcapitata and Selenastrum capricornutum) was assessed according to method OECD 201, and in compliance with OECD GLP (Stephenson, 1983).  Algae were exposed to the substance at a range of concentrations with the aid of acetone as a vehicle (0.1 mL/L) in the dilution water.  The toxic effect measured during the assay was the inhibition of cellular multiplication over a time period of 96 hours.  The study was performed using Erlenmeyer flasks containing 50 mL of test solution inoculated with an algal suspension such that the initial cell concentration was 5x10^2 cells/mL.  Test flasks were incubated at 24 ± 2 °C, continuously shaken and constantly exposed to a light intensity of about 3000 lux.  The algal concentration was measured after 2 and 4 days.  Physico-chemical measurements were carried out on days 0, 2, and 4 of the test.  The concentration of the test substance causing a 50% reduction in cell number (EC50) was determined. None of the cultures grown in the presence of isopropyl ether had a day 4 cell count of less than 80% of the mean control cell count on day 4. The 96 hour EC50 was therefore greater than 1000 mg/L, the maximum concentration tested. The 72-hour data were not collected during the study.

 

Acute toxicity to aquatic algae was estimated using a validated QSAR model with the following result. The Estimation Programs Interface (EPI) Suite United States Environmental Protection Agency ECOSAR Program (v0.99h) returned the result green algae 96 hour EC50 = 134.9 mg/L.