1-Decene, 1-ethoxy-

Toxicity to aquatic algae and cyanobacteria

Description of key information

A study was performed to assess the effect of the test item on the growth of the green alga Pseudokirchneriella subcapitata. The method followed that described in the OECD Guidelines for Testing of Chemicals (2006) No 201, "Freshwater Alga and Cyanobacteria, Growth Inhibition Test". Several time intervals and centrifugation rotations were used to find the maximum water solubility in the test medium. The maximum water solubility in the test media varied from 0.06 - 2.5 mg/l. Finally for the exposure concentrations stirring for 24 hours and filtration through a 0.2 mm sieve were used to achieve the maximum water solubility in the test media, which were diluted thereafter to have 5 test concentrations. At t=0, the measured concentrations were: < LoQ for 6.25 and 12.5 % saturated solutions. At the three higher concentrations the measured values were: 0.009, 0.0245, 0.0786 mg/l. After 24 h at 100% saturated solution 0.0242 mg/l test substance was found. All other concentrations were < LoQ. The substance is not stable under the test conditions. The reason for this remains unclear. Volatility was prevented using fully closed test vessels, it was unlikely to be surface activity (substance is not surface active), oversaturation could be and/or adsorption to algae could be possibilities. Initial measured were considered the most reliable for the exposure to algae and therefore these have been used to calculate the effect concentrations. No effects on growth rate (< 10%) were seen up to 50% saturated solution (0.025 mg/l) and therefore this concentration is considered the NOEC. At 100% saturated solution (0.077 mg/l) 65% growth rate inhibition was observed. The 72h ErC50 was considered to be also 0.077 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

0.077 mg/L

EC10 or NOEC for freshwater algae:

0.025 mg/L