(2,2'-(3,3'-dioxidobiphenyl-4,4'-diyldiazo)bis(6-(4-(3-(diethylamino)propylamino)-6-(3-(diethylammonio)propylamino)-1,3,5-triazin-2-ylamino)-3-sulfonato-1-naphtholato))dicopper(II) acetate lactate

Toxicity to aquatic algae and cyanobacteria

Description of key information

ECb50 (96h): 0.57 mg/l

ECr50 (96h): 1.61 mg/l

NOEC (96h): 0.32 mg/l

Additional information

The influence of the test substance CARTASOL BLAU PE 3562 on the growth of the green algal species Scenedesmus subspicatus CHODAT was investigated in a 96-hour static test according to the Commission Directive 92/69/EEC, Annex Part C.3, dated December 29, 1992, and the OECD Guideline No. 201, adopted June 7, 1984. However, the test
method was modified to quantify the algicidal effect of the test substance, but also the growth inhibition effect caused by reduced light intensities in the coloured test solutions.
The nominal test concentrations were 0.10, 0.32, 1.0, 3.2, 10, 32 and 100 mg test substance/l and a control. The mean analysed test substance concentrations in the freshly prepared test media ranged from 73 Vo to Il5 Vo of the nominal values. In the three highest test concentrations the concentrations of the test item were nearly constant during the test period of 72 hours. However, at the lower test concentration of nominal 0.32 mg/l the test substance concentration in the test medium had significantly decreased during the test period, obviously caused by adsorption of the test substance onto glass surfaces. The total mean measured test concentrations (calculated as the average over
all measurements per test concentration) varied in the range of 67 % to 115 % of the nominal values. Therefore, the reported biological results a¡e based as far as possible on these total mean measured test substance concentrations.
At the algal growth inhibition effect of the test item on Scenedesmus subspicatus the pure light absorption caused by the coloured test substance had no significant influence on the test results. Therefore, the results of the experimental part, where the algae grew in the test media with dissolved test substance as in a usual algal growth inhibition test should be taken into consideration for the determination of the toxic effect of the test substance on the growth of Scenedesmus subspicatus. According to these results the test substance had a statistically significant inhibitory effect on the growth of Scenedesmus subspicatus after the exposure period of 96 hours first at the mean measured test substance concentration of 0.67 mg/l (nominal 1.0 mg/l). Thus, this test concentration was determined as the 96-hour LOEC (lowest concentration tested with toxic effects). The 96-hour NOEC (highest concentration tested without toxic effects after the test period of 96 hours) was determined at the mean measured test substance concentration of 0.21 mg/l
(nominal 0.32 mg/l), since up to and including this test concentration the mean growth rates
of the algae were statistically not significantly lower than in the control.
The EC-values were calculated for the algal biomass b and the growth rate ¡r after 96 hours test duration:

Parameter (0-96 h)	Biomass b (mg/l)	Growth rate µ (mg/l)
EC50 95 % conf. Limits	0.57 n.d.	1.61 0.05-8.36
EC10 95 % conf. Limits	0.08* n.d.	0.11* 0.00-0.66

n.d.: could not be determined
* theoretical value calculated by Probit analysis, however the biological test had clearly demonstrated no
growth inhibition up to the mean measured test substance concentration of 0.21 mg/l (nominal 0.32
mg/l)