N,N-bis(2-hydroxypropyl)benzamide

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From July 16th to August 30th, 2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

For the analysis of the actual test item concentrations the following samples were taken:
Just before test start: - duplicate samples from the test medium (without daphnids)
- duplicate samples from the control (without daphnids)
After 48 hours (stability samples): - duplicate samples from the test medium
- duplicate samples from the control
For the 48-hour stability smples the contents of the two respective test beakers were combined.
All samples were deep-frozen (at about -20 °C) immediately after sampling. Based on pre-experiments for investigation of the storage stability (non-GLP) the test item is sufficiently stable in the test water under these storage conditions.
The concentration of test item was analyzed in the duplicate test medium samples of the single test concentration for both sampling times (0 and 48 hours).
From the control only one of teh duplicate samples was analyzed from each of both sampling times.

Vehicle:

no

Details on test solutions:

Only nominal concentration of 100 mg/L was tested. Test medium was prepared by dissolving 30 mg of test item completely in 300 mL of test water by ultrasonic treatment and intense stirring at room temperature.

Test organisms (species):

Daphnia magna

Details on test organisms:

The study was performed with young daphnids 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, defined from the supplier as clone 5. Since this date the clone is bred in the laboratories of RCC in reconstituted water of the quality identical to the one used in the tests (considering pH, main ions and total hardness) and under temperature and light conditions identical of those of the tests.
At the start of the test organisms were 6-24 hours old and were not first brood progeny.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

Not specified

Hardness:

2.5 mmol/L (250 mg/L) as CaCO3

Test temperature:

Water temperature: 21 °C

pH:

8.0

Dissolved oxygen:

8.3-8.4 mg/L

Salinity:

Analytical grade salts were dissolved in purified water to obtain the following nominal concentrations:
CaCl2 * 2H2O: 2.0 mmol/L
MgSO4 * 7H2O: 0.5 mmol/L
NaHCO3: 0.75 mmol/L
KCl: 0.075 mmol/L

Conductivity:

Not specified

Nominal and measured concentrations:

1) 0 mg/L (control)
2) nominal: 100 mg/L
Measured (start): 94 mg/L
Measured (end): 91 mg/L

Details on test conditions:

The test was performed in 100 mL glass beakers filled with 50 mL test medium. Beakers were covered with glass plates to reduce the loss of water and to avoid the entry of dust into the solutions.
At the single test concentration and for the control 20 daphnids were used, divided into two replicates of ten daphnida each. The daphnids were randomly distributed to the test vessels at initiation of the test. The loading rate was lower than one daphnia per 2 mL test solution.
Light conditions: a 16-hour light to 8-hour darkness photoperiod (with a 30 minutes transition period). Light intensity during light period was between 200 and 1200 Lux.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Test item was stable during test period.
No immobilized or dead test organisms were observed during the test period of 48 hours at a concentration of 100 mg/L both in control and test concentrations.
The test medium was a clear solution throughout the whole test duration.
Analytically measured test item concentration was 94% of the nominal at the start and 91% of the nominal at the end of the experiment. Thus, test item was stable during the test and the study is considered valid.

Results with reference substance (positive control):

Not performed

Validity criteria fulfilled:

yes

Conclusions:

No effects of test item were found after 48 hours in a limit test at the concentration of 100 mg/L.
Therefore LC50 of the substance on Daphnia Magna is higher than 100 mg/L.

Executive summary:

Acute aquatic toxicity of the substance on invertabrates was determined in a 48 -hour study on Daphnia Magna according to OECD TG 202. A limit test was performed at 100 mg/L. No immobilized or dead organisms or other signs of intoxication were determined during test period neither in the control nor at test concentration of 100 mg/L. Analytically measured test item concentration was 94% of the nominal at the start and 91% of the nominal at the end of the experiment. Thus, test item was stable during the test and the study is considered valid.

LC50 of the substance was therefore determined to be higher than 100 mg/L.

Description of key information

In a study according to OECD TG 202, LC50 after 48 hours on freshwater invertebrates was determined to be higher than 100 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L