α,α,α',α'-tetramethylxylene-α,α-diol

Toxicity to aquatic algae and cyanobacteria

Description of key information

The 72h EC50 for average specific growth rate and yield could not be calculated due to the lack of fractional inhibition, and it is therefore estimated to be > 100 mg/L. The NOEC was estimated to be 100 mg/L.

Key value for chemical safety assessment

EC10 or NOEC for freshwater algae:

100 mg/L

Additional information

This study was designed to determine the effects of the reaction mass a, a, a', a'-tetramethyl-m-xylene-a, a'-diol and a, a, a', a'-tetramethyl-p-xylene-a, a'-diol (m/p DIOL) on the growth of Pseudokirchneriella subcapitata, a unicellular freshwater green alga, over a 72 h period. The study was performed to meet the requirements of OECD (2006) Guideline 201.

 

Based on the results from the range finding test, the definitive test was conducted with nominal concentrations of 6.25, 12.5, 25, 50 and 100 mg/L m/p DIOL, together with an untreated control. The corresponding mean measured (0 and 72 h) concentrations of m/p DIOL were 5.87, 12.21, 23.77, 47.04 and 96.58 mg/L, respectively. Chemical analysis of test samples taken at 0 and 72 h indicated that concentrations of m/p DIOL were maintained over the 72 h test period, with concentrations in the range 95% to 101% of the initial measured values.

 

The 72h EC50 for average specific growth rate and yield could not be calculated due to the lack of fractional inhibition, and it is therefore estimated to be > 100 mg/L. The NOEC was estimated to be 100 mg/L.

OECD Guideline 201 validity criteria were met and therefore the test was considered to be acceptable