Registration Dossier

Diss Factsheets

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
May 2017 - February 2019
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Justification for type of information:
See statement of laboratory attached and the notification of the Echa DCG 10.3 issue of the 29.05.2018. Enquiry No.: INC000000236739.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2019

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
yes
Remarks:
All deviations were stated as uncritical.
Qualifier:
according to guideline
Guideline:
EU Method C.3 (Algal Inhibition test)
Deviations:
yes
Remarks:
All deviations were stated as uncritical.
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
C.I. Solvent Red 119
EC Number:
602-676-8
Cas Number:
12237-27-3
Molecular formula:
C32H22N10O8Cr
IUPAC Name:
C.I. Solvent Red 119
impurity 1
Reference substance name:
Unknown impurities
Cas Number:
not available
IUPAC Name:
Unknown impurities
impurity 2
Chemical structure
Reference substance name:
Water
EC Number:
231-791-2
EC Name:
Water
Cas Number:
7732-18-5
Molecular formula:
H2O
IUPAC Name:
water
Test material form:
solid: particulate/powder

Results and discussion

Effect concentrations
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 0.27 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Three experiments were performed. In the 1st experiment one of the validity criteria (coefficient
of variation of average growth rate during the whole test period) was not met. Therefore,
the experiment was repeated. In the 2nd experiment, all solutions containing solvents
showed strong turbidity and similar inhibition values. Since the measured values are not
meaningful due to the turbidity that occurred, this experiment was declared invalid. The
results of these experiments are not stated in this report, but will be kept together with the
other raw data in the GLP archive of the test facility.
The 3rd experiment was valid and plausible.
The study was performed using 5 concentrations ranging from 0.05 to 0.5 mg/L. During
validation the estimated solubility of the test item in test media was 0.472 mg/L. Therefore,
the concentration 0.5 mg/L was used as highest test concentration. The cell concentration
of each replicate was determined by measuring the cell numbers every 24 hours with an
electronic particle counter. Growth rate μ and the yield2 were determined from the cell
number at the respective observation times. The comparison of blank control and solvent
control showed no influence of methanol on algae growth. Therefore, blank control (without
solvent) is used for evaluation. Significant inhibition of algal growth was observed only
at the highest tested concentration.
At the start and at the end of the test, the content of the test item in the test solutions was
determined using a photometric method.
The measured concentrations lay between 50% and 70 % of the nominal concentrations at
the beginning of the test. After 72 hours incubation the measured concentrations were increased.
This was caused by the reaction of the test substance with the algae, which falsified
the photometric measurement. For this reason, only the measured initial values are
used for statistical evaluation.
Due to the low inhibition values, only a range can be given for the EC10 (growth rate) and
EC50 value.
The 72h-EC50 values of potassium dichromate were determined in a separate reference
test. For the estimation of the 72h-EC50 values of the positive control, the fits showed sufficient
statistical correspondence of the data with the dose-response-equation. The values
were within the range of the laboratory.
The pH of the blank control should not fluctuate by more than 1.5 units. The change was
0.4 units in the blank control.
All validity criteria were met.
No observations were made which might cause doubts concerning the validity of the study
outcome. The result of the test can be considered valid.
Executive summary:

Three experiments were performed. In the 1st experiment one of the validity criteria (coefficient

of variation of average growth rate during the whole test period) was not met. Therefore,

the experiment was repeated. In the 2nd experiment, all solutions containing solvent

showed strong turbidity and similar inhibition values. Since the measured values are not

meaningful due to the turbidity that occurred, this experiment was declared invalid. The

results of these experiments are not stated in this report, but will be kept together with the

other raw data in the GLP archive of the test facility.

The 3rd experiment was valid and plausible.

The study was performed using 5 concentrations ranging from 0.05 to 0.5 mg/L (nominal).

During validation the estimated solubility of the test item in test media was 0.472 mg/L.

Therefore, the concentration 0.5 mg/L was used as highest test concentration. Incubation

time (test system Desmodesmus subspicatus) was 72 hours. The cell concentration of

each replicate was determined by measuring the cell numbers every 24 hours with an

electronic particle counter. Growth rate μ and the yield1 were determined from the cell

number at the respective observation times.

The comparison of blank control and solvent control showed no influence of methanol on

algal growth. Therefore, blank control (without solvent) is used for evaluation.

Significant inhibition of algal growth was observed only at the highest tested concentration.

At the start and at the end of the test, the content of the test item in the test solutions was

determined using a photometric method.

The measured concentrations lay between 50% and 70 % of the nominal concentrations at

the beginning of the test. After 72 hours incubation the measured concentrations were increased.

This was caused by the reaction of the test substance with the algae, which falsified

the photometric measurement. For this reason, only the measured initial values are

used for statistical evaluation (cf. OECD Guideline 201, §40).

Due to the low inhibition values, only a range can be given for the EC10 (growth rate) and

EC50 values.

The 72h-EC50 values of potassium dichromate (K2Cr2O7, CAS No. 7778-50-9) were determined

in a separate reference test. The values lay within the range of the laboratory

(growth rate 0.73 - 1.10 mg/L, yield 0.21 – 0.66 mg/L).

The following results for the test item Solvent Red 119 were determined:

Table 3-a       Results of the test item

Endpoint              NOEC              LOEC              EC10              EC50

Growth Rate       0.14 mg/L         0.27 mg/L        > 0.27 mg/L    > 0.27 mg/L

Yield                   0.14 mg/L         0.27 mg/L        0.23 mg/L       > 0.27 mg/L

Categories Display