Registration Dossier

Ecotoxicological information

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
long-term toxicity to aquatic invertebrates
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Not conducted according current guideline but study well documented and meeting generally accepted scientific principles

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Effects of various metals on survival, growth, reproduction and metabolism of Daphnia magna
Author:
Biesinger K. E. and Christensen G. M.
Year:
1972
Bibliographic source:
Journal fisheries Research Board of Canada, Vol. 29 No. 12, 1972
Reference Type:
secondary source
Title:
Barium and Barium Compounds
Author:
World Health Organization
Year:
2001
Bibliographic source:
Concise International Chemical Assessment Document 33. World Health Organisation (Geneva)

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 211 (Daphnia magna Reproduction Test)
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
not specified

Test solutions

Vehicle:
no
Details on test solutions:
The number of concentrations tested ranged from 5 to 12 dependent on the toxicant and the initial effects observed.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
- Strain: laboratory clone
- Source: University of Michigan
- Age at study initiation (mean and range, SD): 12h +/- 12h

Study design

Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
21 d

Test conditions

Hardness:
Mean: 45.3 mg/L (Range: 44.0 - 53.0)
Test temperature:
18 +/- 1 °C
pH:
Mean: 7.74 (Range: 7.4 - 8.2)
Dissolved oxygen:
Near saturation
Details on test conditions:
Five Daphnids were placed in 200 mL of water in 250-mL beaker. Four beaker (the test chambers) were used with a total of 20 animals for each experimental and control condition for each test. The test chambers were covered with a pane of glass to minimize evaporation and distributed randomly in a constant temperature room.. Young daphnids were placed in test chambers into new medium at the beginning of each week and subjected to test conditions for 3 weeks. Survival of the initial animals was noted after1, 2 and 3 weeks. At the end of three weeksthe surviving animals were weighed and prepared for protein and GOT analyses. Reproduction was assessed by counting the young produced each week. Light intensity of about 115 ft-c at the water interface was provided. An automatically controlled16-hr photoperiod was used.

Results and discussion

Effect concentrationsopen allclose all
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
8.9 mg/L
Nominal / measured:
nominal
Conc. based on:
element
Basis for effect:
reproduction
Duration:
21 d
Dose descriptor:
other: EC16
Effect conc.:
5.8 mg/L
Nominal / measured:
nominal
Conc. based on:
element
Basis for effect:
reproduction
Reported statistics and error estimates:
Results were statistically evaluated with the method of Lichtfield and Wilcoxon (1949) for establishing appoximations of the 95% confidence limit for survival. Reproductive effects were analyzed in a similar manner excluding confidence limits, but are given in terms of reproductive impairment by percentage. Both 50% and 16% reproduction-impairments are given. These values imply decreases in the total number of youngproduced as compared with the control. The 16% reproductive-impairment concentration is given since it represented a minimal reproducible value below which the variability in reproduction could not be detected from controls.

Applicant's summary and conclusion