2-Naphthalenesulfonic acid, 7-amino-4-hydroxy-8-[2-[2-sulfo-4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]diazenyl]-, potassium sodium salt (1:?:?), coupled with diazotized 2-[(4-amino-5-methoxy-2-methylphenyl)sulfonyl]ethyl hydrogen sulfate

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experiment start date - 19 June 2007; Experiment end date - 29 July 2007; Study completion date - 31 August 2007.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.20 (Daphnia magna Reproduction Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Identity: FAT 40812/A
Batch: WP 8/03
Purity: approx. 75 %
Appearance: Solid, dark red-brownish powder
Expiration date: 23 April 2010
Storage: At room temperature at about 20 °C

Analytical monitoring:

yes

Details on sampling:

For the determination of the test substance concentrations, duplicate samples were taken from the freshly prepared test media of all test concentrations and the control at the first treatment period (Day 0), at a treatment period in the second week (Day 7) and at the last treatment period (Day 16). To determine the maintenance of the test substance concentrations in the media, stability control samples were taken at the end of two test medium renewal periods of 48 hours (Days 2 and 9) and at the end of one renewal period of 72 hours (Day 19). The following stability samples were taken in duplicate: Samples with food, taken from the actual test by combining the contents of the test beakers after the end of the treatment period. Samples without food and test animals, incubated during the renewal periods under the test conditions. All samples were deep-frozen (at about -20 °C) immediately after sampling. The concentrations of the test substance were determined in at least one of the duplicate test media samples from the nominal concentrations of 11 and 34 mg/L, determined in the experiment as the NOEC and the LOEC. The test concentrations below the NOEC were not analyzed, because they were not relevant for the interpretation of the biological results. From the control samples, one of the duplicate samples of each of the sampling dates was analyzed.

Vehicle:

no

Details on test solutions:

Prior to the start of the test and prior to each medium removal, the test medium of the highest nominal test concentration of 110 mg/L was freshly prepared by dissolving 165 mg (dosed in the range of 165.0-165.3) of the test item completely in 1500 mL of test water using ultrasonification and intense stirring.

Test organisms (species):

Daphnia magna

Details on test organisms:

The study has been performed with females of a clone of the species Daphnia magna Straus. A clone of this species was originally supplied by the University of Sheffield/UK in 1992. Since this date, the clone is successfully bred in RCC's laboratories in culture medium identical to the medium used for the test. The temperature and light conditions were identical to those of the test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

250 mg/L as CaCO3

Test temperature:

19 - 21 °C

pH:

7.5 - 8

Dissolved oxygen:

at least 8.0 mg/L

Nominal and measured concentrations:

- Nominal concentrations: 0 (control), 1.1, 3.4, 11, 34, 110 mg/L.
- Analytical concentrations: 98-106 % of nominal at the start and 93-102 % of nominal at the end of the test (only 11 and 34 mg/L test concentrations measured).

Details on test conditions:

- The study was started with 10 Daphnia per test concentration and control. Each Daphnia was kept individually in a glass-beaker ( 100 mL) containing 80 mL test medium. The beakers were covered glass plates. The test was performed in a temperature controlled room. Light conditions were as follows: 16 hours light and 8 hours darkness with a 30-minute transition period (approx. 490 - 650 Lux).
- In this semistatic test the test media of all test concentrations and of the control were renewed on Days 2, 5, 7, 9, 12, 14, 16 and 19 of the test period (every Monday, Wednesday and Friday). At these dates the test animals were carefully transferred by glass tubes from the old test vessels into the freshly prepared test media.
- The test animals were fed on each working day (Monday through Friday) with a food mixture containing a suspension of green algae of the Scenedesmus subspicatus (freshly grown in the laboratories of RCC) and a fish food suspension (10g of a commercial fish diet (TETRAMIN Hauptfutter, obtained from TETRA-Werke, D-49324 Melle, Germany) were powdered and suspended in 500mL of test water. The suspension was allowed to stand for 4 hours. Then, 400 mL of the supernatant were taken, diluted 1:1 with test water and boiled. The suspension was stored deep frozen in small quantities until use). The carbon contents of the algal and fish food suspensions were determined using a Shimadzu TOC 5000A Analyzer. The food amounts were based on the measured concentrations of total organic carbon (TOC) in the food suspensions and consisted of 50 % algae and 50 % fish food (based on TOC).
- The test replicates were observed for mortality of adults at the start of the test, on the first and second day after the start of the study and thereafter at least three times per week before renewal of the test media. On the same observation dates, the number of offspring was recorded. The test beakers were also checked for the presence of aborted eggs or dead offspring.

Reference substance (positive control):

no

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

11 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: mortality and reproduction

Details on results:

- In the control and at the lower test concentrations up and including 11 mg/L the survival of the test animals at the end of the test was 100 %. At the next higher test concentration of 34 mg/L the survival was 30 %. At the highest test concentration of 110 mg/L, all test animals were dead at the observation on Day 19. Thus, the survival after 21 days was significantly reduced (>20 %) first at the test concentration of 34 mg/L.
- The time of the first brood was not affected up to and including the highest test concentration of 110 mg/L.
- The mean reproduction rate of the daphnids in the control was 94.4 ± 8.1 living offspring per adult. No inhibitory effect of the test substance on the mean reproduction rate was determined up to and including the test concentration of 34 mg/L, which was the highest test concentration with surviving daphnids. At these test concentrations, the mean reproduction rates were even slightly higher compared to the control. At the highest test concentration of 110 mg/L, no daphnids survived until test end.
- The 21-day EC50 for the reproduction rate could not be calculated since no inhibition was observed up to 34 mg/L. Thus the 21-day EC50 was >34 mg/L.
- With the exception of the reported mortality, no visible abnormalities were observed at the test animals during the test.

Validity criteria fulfilled:

yes

Conclusions:

The NOEC after the exposure period of 21 days was 11 mg test substance/L.

Executive summary:

In a GLP-compliant daphnia magna reproduction test, performed according to OECD Guideline 211, the effect of the test substance on survival and reproduction of daphnia magna was investigated. Daphnids were exposed to nominal concentration of 1.1, 3.4, 11, 34, and 110 mg/L of the test substance for 21 days under semi-static conditions. The analytically determined test substance concentrations in the analysed test media varied in the range from 98 % to 106 % of the nominal values at the start and in the range from 93 to 102 % at the end of the test medium renewal periods. The test substance was sufficiently stable in the test water at least over the longest renewal periods of 72 hours. In the control and at the lower test concentrations up and including 11 mg/L the survival of the test animals at the end of the test was 100 %. At the next higher test concentration of 34 mg/L the survival was 30 %. At the highest test concentration of 110 mg/L, all test animals were dead at the observation on Day 19. The time of the first brood was not affected up to and including the highest test concentration of 110 mg/L. No inhibitory effect of the test substance on the mean reproduction rate was determined up to and including the test concentration of 34 mg/L, which was the highest test concentration with surviving daphnids. At these test concentrations, the mean reproduction rates were even slightly higher compared to the control. Taking into account the survival and the reproduction of the test animals, the NOEC was 11 mg/L.

Description of key information

The 21-day NOEC is 11 mg/L in Daphnia magna.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

11 mg/L

Additional information

In a GLP compliant daphnia magna reproduction test, performed according to OECD Guideline 211, the effect of the test substance on survival and reproduction of daphnia magna was investigated. Daphnids were exposed to nominal concentration of 1.1, 3.4, 11, 34, and 110 mg/L of the test substance for 21 days under semi-static conditions. The analytically determined test substance concentrations in the analysed test media varied in the range from 98 % to 106 % of the nominal values at the start and in the range from 93 to 102 % at the end of the test medium renewal periods. The test substance was sufficiently stable in the test water at least over the longest renewal periods of 72 hours. In the control and at the lower test concentrations up and including 11 mg/L the survival of the test animals at the end of the test was 100 %. At the next higher test concentration of 34 mg/L the survival was 30 %. At the highest test concentration of 110 mg/L, all test animals were dead at the observation on Day 19. The time of the first brood was not affected up to and including the highest test concentration of 110 mg/L. No inhibitory effect of the test substance on the mean reproduction rate was determined up to and including the test concentration of 34 mg/L, which was the highest test concentration with surviving daphnids. At these test concentrations, the mean reproduction rates were even slightly higher compared to the control. Taking the survival and the reproduction rate of the test animals into account, the NOEC was 11 mg/L.