Registration Dossier

Ecotoxicological information

Long-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
long-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP, near guideline, experimental study, published in peer reviewed literature; minor restrictions in design and/or reporting but otherwise adequate for assessment.
Qualifier:
according to guideline
Guideline:
other: In accordance with the “Provisional Procedure: extended toxicology test with Daphnia magna (determination of NOEC for reproduction rate, mortality and the time of first appearance of offspring; 21d)” as of 1 January 1984, Federal Environmental Agency.
Deviations:
not specified
Principles of method if other than guideline:
21 day semi-static closed vessel Daphnia reproduction test. Conducted in line with the provisional procedure proposed by the West German Federal Environmental Agency
GLP compliance:
no
Remarks:
No data reported
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
No data reported
Analytical monitoring:
yes
Details on sampling:
The concentration in the initial preparations and in the test and blank (no test organisms or feed) preparations were determined after 48/72 hours. Samples taken twice during the test period from selected concentrations and analysed, once before the 7th day and once between the 16th and 21st day.
Vehicle:
no
Details on test solutions:
Substances tested firstly fully diluted using magnetic stirrers for 24h. Graduated dilutions prepared from stock solutions.
Test organisms (species):
Daphnia magna
Details on test organisms:
20-30 specimens in forty 2-L beakers, filled with at least 1.6 L Berlin tap water. 24 h-old animals. Culture area regulated at 20°C.
Test type:
other: semi-static, closed vessels
Water media type:
freshwater
Limit test:
no
Total exposure duration:
21 d
Post exposure observation period:
None
Hardness:
German hardness 16°
Test temperature:
25±1°C
pH:
pH was never lower than the 7.0
Dissolved oxygen:
Average minimum oxygen saturation value of 58%.
Salinity:
Not applicable
Nominal and measured concentrations:
Stock solution concentration: 63 mg/L.
Dilution steps corresponded to a ratio of 1:2.
Details on test conditions:
Four test vessels per concentration and four controls. 20 animals per concentration level. Feeding took place on the days when parent animals were transferred. Overall COD of 15-20 mg/L as the daily feed amount. Lit from 7am to 4pm with fluorescent lamps - Philips TL 40/25W.
Observations: Dead parent animals removed. Offspring counted, total number for each test vessel was recorded. pH value and oxygen concentration measured in two test vessels per concentration level.
Reference substance (positive control):
not specified
Key result
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
0.4 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
reproduction
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
2 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
reproduction
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
ca. 50 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Details on results:
Chemical analysis showed a loss of 1,3,5-trimethylbenzene of more than 20%. No chemical analysis was available for the 24h EC50.
Results with reference substance (positive control):
No data reported
Reported statistics and error estimates:
No data reported

Validity criteria met: reproduction rate per parent animal after 21 days was 68.0 offspring. Parent animal mortality after 21 days was 9.1%. The pH was never lower than the 7.0 in any of the control or test preparations. Average minimum oxygen saturation vale of 58%.

Validity criteria fulfilled:
yes
Remarks:
see remarks on results
Conclusions:
The minimum 21 day NOEC value was determined to be 0.4 mg/L based on chemical analysis. 1,3,5-trimethylbenzene was most sensitive to reproduction rate.
Executive summary:

This study is not GLP compliant but follows a standard guideline. There are limitations in the design and reporting but it is suitable for use for this endpoint. The minimum 21 day NOEC value was determined to be 0.4 mg/L based on chemical analysis. 1,3,5-trimethylbenzene was most sensitive to reproduction rate.

Description of key information

The 21 day NOEC value was determined to be 0.4 mg/L based on chemical analysis. 1,3,5-trimethylbenzene was most sensitive to reproduction rate.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates
Effect concentration:
0.4 mg/L

Additional information

Based on the information available, the study by Kühn et al (1981) is considered to be the key study. The study is not GLP compliant but follows a standard guideline. There are limitations in the design and reporting but it is considered suitable for use as the key study for this endpoint. The 21 day NOEC value for Daphnia magna exposed to 1,3,5-trimethylbenzene was determined to be 0.4 mg/L based on chemical analysis. 1,3,5-trimethylbenzene was most sensitive to reproduction rate.