Diethylbenzene

Toxicity to aquatic algae and cyanobacteria

Description of key information

Acute toxicity data were available for diethylbenzene exposure to the green algae, Pseudokirhneriella subcaptiata (formerly known as Selenastrum capricornutum.  The key study reported a 72-hour EC50 and NOEC value for diethlybenzene

Key value for chemical safety assessment

EC50 for freshwater algae:

1.21 mg/L

EC10 or NOEC for freshwater algae:

0.547 mg/L

Additional information

Two acute toxicity studies with Pseudokirchneriella subcapitata (formerly known as Selenastrum capricornutum) are available for exposure to diethlybenzene and polyethlybenzene. One static study, rated a Klimisch score of 1 and conducted under GLP was chosen as the key study. This study determined the acute toxicity as reduced growth rate and biomass of a blend of diethlybenzene during a 72-hour exposure. A phytotoxicity test was conducted at ABC Laboratories, Inc., Columbia, Missouri, to determine the effect of a diethylbenzene blend on the green alga, Selenastrum capricornutum. The definitive test was conducted for 72 hours commencing when the test flasks were inoculated with algae. Nine replicates were used for the control, vehicle control and each test concentration. Based on area under the growth curve, the 72-hour EbC50, for the diethylbenzene blend was 1.00 mg ai./L. The 72-hour NOEC, based on area under the growth curve, was 0.547 mg a.i./L. Based on growth rate, the 72-hour ErC50 for the diethylbenzene blend was 1.21 mg a.i./L. The 72-hour NOEC, based on growth rate, was 0.547 mg a.i/L.