Registration Dossier

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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to the O.E.C.D. test guideline 201 with GLP compliance.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011
Report Date:
2011

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: Liquid at room temperature.
Details on test material:
As per IUCLID5 Sections 1.1. 1.2. and 4.1.

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
yes
Details on test solutions:
For test concentrations prepared in the range- finding test, stock solutions were prepared at concentrations of 20, 100 and 200 mg/L by adding the required nominal amount of test substance in the diluent, Algal stock culture medium (Woods Hole) and mixing the solution for approximately 2 hours. For test concentrations prepared in the definitive test, stock solutions were prepared at concentrations of 40, 80 and 160 mg/L by adding the required nominal amount of test substance in the diluent, and mixing the solution for approximately 2 hours.

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
Pseudokirchneriellasubcapitata (formerly Selenastrum capricornutum), one of the freshwater alga species specified in the O.E.C.D. guideline was maintained at STILLMEADOW, Inc. Mass algal culture was initiated 3-7 + 1 days prior to dosing. The algae were maintained in Algal stock culture medium (Woods Hole) with EDTA up to 0.300 mg/L, at a temperature of 22-25°C with Continuous lighting approximately 422 fi. c. and continuous aeration.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h
Post exposure observation period:
None

Test conditions

Hardness:
No data
Test temperature:
22-25°C
pH:
7.9-10
Dissolved oxygen:
Saturated
Salinity:
No data
Nominal and measured concentrations:
5, 10, 20, 40 and 80 mg/L nominal.
Details on test conditions:
Treatment was conducted in 250-mL sterile Erlenmeyer flasks with stoppers and aeration tubing and 50,000 cells/mL. There were three flasks for each test substance concentration and six flasks for the untreated control. A positive control group consisted of three flasks treated with 10 mg/L zinc chloride. The flasks were set on a shaker table for constant agitation at approximately 100 cycles/minute. At 24, 48 and 72 hours following dosing, observations of inhibition were made for each test container by measuring the mean cell density with a hemacytometer. The temperature was recorded daily, and the pH of each container was recorded at study termination.


Reference substance (positive control):
yes
Remarks:
Zinc chloride at 10 mg/L.

Results and discussion

Effect concentrations
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
ca. 20.4 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
cell number
Remarks on result:
other: 17.6-24.5 mg/L.
Details on results:
Little or no increase in cell number was observed at the test substance concentrations of 40 and 80 mg/L throught the study. The relative precent survival at 20 mg/L was 47.9 at 72 hr. The percent survial of the 10 mg/L concentration was 85.9% ay 72 hr and is considered the NOEC.
Results with reference substance (positive control):
There was no increase in algal cell number with the positive control zinc chloride.
Reported statistics and error estimates:
The NOEC and EC50 values were determined by a commercially available statistical program (ToxCalc Version 5.OTM). The Maximum Likelihood-Logit model was selected for the determination in this case. The 95% confidence Limits on the EC50 value were 17.6-24.5 mg/L.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The estimated EC50 value for the test substance was 20.4 mg/L with 95% confidence Limits of 17.6-24.5 mg/L. This EC50 value is the lowest of the three aquatic species and is therefore the most appropriate value for derivation of PNEC values.
Executive summary:

The acute toxicity of the test substance, Formaldehyde, polymer with 1,3 -benzenedimethanamine and phenol to algae was determined in an O.E.C.D. test guideline 201 study. The estimated EC50 value for the test substance was 20.4 mg/L with 95% confidence Limits of 17.6-24.5 mg/L following 72 hr of exposure. .