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EC number: 931-335-9
CAS number: 90622-74-5
The analytically determined concentrations of the test substance test
substance in the samples from the freshly prepared stock solutions
ranged from 86% to 104% of the nominal concentration.
The measured test substance concentrations in the samples from the
freshly prepared test media of the very low test concentration of
nominal 0.032 mg/L (in the range of the determination limit of the
analytical method) varied from 85% to 171% of the nominal concentration.
However, in this concentration range the measured values in the control
samples must be taken into account. But for the biological results this
low test concentration is of no importance.
The analytically determined concentrations of test substance in the
samples from the freshly prepared test media of the biologically
relevant test concentrations of nominal 0.10 and 0.32 mg/L varied in the
range from 85% to 109% of the nominal values. The mean measured values
of all measurements of the freshly prepared test media of nominal 0.10
mg/L amounted to 100%, and at the test concentration of nominal 0.32
mg/L to 86% of the respective nominal value.
During the test medium renewal periods of 48 and 72 h, the test
substance concentrations decreased. At the test concentration of nominal
0.10 mg/L only 15% to 25% of the nominal value were found in the
samples, taken out of the actual biological test after the 48
respectively 72 h exposure periods. However, 63% to 75% of nominal were
found at that dates in test media, which were incubated with algae but
without test animals under the test conditions in parallel to the actual
The reason for these differences are unknown, but two possible reasons
must be taken into consideration:
firstly the algal cell densities were lower in the actual test media due
to the filtration and consumption of algae by the test animals during
the renewal periods, but the influence of the algae on the analytical
results is unknown.
Secondly, in the actual test media the test substance might have been
stronger biodegraded due to the inocculation of bacteria with the drop
of old test media at the transfer of the test animals from the old test
media into the freshly prepared test media at each test medium renewal
date. On the other side it is quite possible that the test substance
adsorbed on the algal cells. In this case Daphnia can take up the test
substance also via food. And toxic effects due to an uptake via food
cannot be divided from the total toxic response determined in the
the influence of all these factors cannot be quantified, the biological
results (NOEC and LOEC) are based on the arithmetical mean value between
the mean measured concentrations in the freshly prepared test media (as
given in the tables with the analytical results), and the mean measured
values in the 48 respectively 72 h old test media (i.e., at nominal 0.10
mg/L, this arithmetical mean measured concentration amounted to 0.073
mg/L, at nominal 0.32 mg/L to 0.244 mg/L).
A study was carried out to determine
the chronic toxicity of the test substance, C12-18 and C18-unsatd. DEA,
to Daphnia magna according to OECD Guideline 211, in compliance with
GLP. Groups of ten daphnids were exposed to the substance (dispersed in
test medium by intensive stirrring) in a concentration range of 0.010 to
1.0 mg/L for 21 d under semi-static conditions. Survival and
reproduction were determined three times per week. Single samples of the
100 mg/L stock solution and duplicate samples of 0.032, 0.10 and 0.32
mg/L test solutions were collected on Days 0, 12 and 16 for analytical
dose verification by HPLC-UV. In the controls and at the test
concentrations up to and including 0.10 mg/L, the survival rate of
parental animals after 21 d was ≥ 80%. At 0.32 mg/L, the mortality rate
increased to 50%. At the highest test concentration of 1.0 mg/L, all
Daphnia were dead at the observation on Day 5. With exception of the
reported mortality, no particular signs of intoxication were observed
during the study. The first young Daphnia released from their parents
were recorded in the control and at the test concentrations up to and
including 0.32 mg/L at the observation on Day 9. At the highest
concentration of 1.0 mg/L, no offspring were recorded. The mean
reproduction rate of control Daphnia was 107.0 ± 14.7 alive offspring
per adult. According to the results of a Willians Test (one-sided, α =
0.05), the reproduction rate of surviving test animals was not
significantly reduced up to and including 0.32 mg/L. The corresponding
analytically determined concentrations at 0.10 and 0.32 mg/L were 0.07
and 0.24 mg/L, respectively. Under the study conditions, the nominal 21
d NOEC and LOEC values were 0.10 and 0.32 mg/L, equivalent to mean
measured values of 0.07 and 0.24 mg/L, respectively (Memmert, 1995).
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
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