Reaction mass of Benzenepropanal, 4-ethyl-α,α-dimethyl- and 3-(2-ethylphenyl)-2,2-dimethylpropanal

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

05 Dec 2016 to 09 Dec 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

1992

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Version / remarks:

2008

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Water samples were taken from the control, solvent control and the 0.87 mg/L test concentration at 0 and 72 hours from fresh media and at 24 and 96 hours from old media for quantitative analysis. Duplicate samples and samples at 24 (fresh media), 48 (old and fresh media) and 72 hours (old media) were taken and stored frozen for further analysis if necessary.

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
In view of the difficulties associated with the evaluation of aquatic toxicity of poorly water soluble test items, a modification of the standard method for the preparation of aqueous media was performed (OECD, 2000). A solvent stock solution was prepared by dissolving the test item in dimethylformamide. An aliquot of this solvent stock solution was dispersed in test water with the aid of magnetic stirring for approximately 10 minutes. After the stirring period, the preparation was filtered (0.2 μm Sartorious Sartopore filter, first approximate 2 liters discarded in order to pre-condition the filter) to ensure any undissolved test item was removed.

- Method: A nominal amount of test item (200 mg) was dissolved in 10 mL of dimethylformamide to produce a 20 mg/mL solvent stock. An aliquot (4.25 mL) of the solvent stock was dispersed in 10 mL of dimethylformamide to produce the 8.7 mg/mL solvent stock. A further aliquot (2.2 mL) of this second solvent stock was dispersed in the test water with the aid of vigorous magnetic stirring for 10 minutes. After the stirring was stopped, any undissolved test item was removed by filtration through a 0.2 μm Sartorius Sartopore filter (first approximate 2 litres discarded in order to pre-condition the filter) to give the 0.87 mg/L test concentration. Each of the solvent stock solutions was inverted several times to ensure adequate mixing and homogeneity.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Source: Brow Well Fisheries Limited, Hebden, near Skipton, Yorkshire, UK
- Length at the end of the definitive test: 5.5 cm (sd = 0.40)
- Weight at the end of the definitive test: 1.3 g (sd = 0.27)

ACCLIMATION
- Acclimation period: 7 days (28 November 2016 to 05 December 2016)
- Acclimation conditions: Fish were maintained in a glass fiber tank with a "single pass" water renewal system. The water temperature was controlled at 14 °C with a dissolved oxygen content of greater than or equal to 9.3 mg O2/L.
- Photoperiod: 16h light : 8h dark with 20 minute dawn and dusk transition periods.
- Type and amount of food during acclimation: The stock fish were fed commercial trout pellets
- Feeding frequency during acclimation: Feeding was discontinued 24h prior to the start of the definitive test
- Health during acclimation: no mortality observed

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

Approximately 140 mg/L (as CaCO3)

Test temperature:

14 - 15 °C

pH:

7.6 - 8.0

Dissolved oxygen:

8.2 - 11.6 mg O2/L

Conductivity:

112.000 - 551.000 µS/cm at 20 °C

Nominal and measured concentrations:

- Nominal concentrations: 0 (control), 0 (solvent control) and 0.87 mg/L; see 'Any other information on materials and methods incl. tables' for test concentration considerations.
- Measured concentrations:

Details on test conditions:

TEST SYSTEM
- Test vessel: glass exposure vessels
- Type: closed
- Fill volume: Glass, 20 liters
- Aeration: The test vessels were aerated via narrow bore glass tubes
- Renewal rate of test solution: Daily
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): 1
- Biomass loading rate: 0.46 g bodyweight/liter (static volume)

TEST MEDIUM / WATER PARAMETERS
- Total organic carbon: 0.850 - 1.325 mg/L
- Pesticides: 0.002 - 0.136 µg/L
- Chlorine: 0.090 - 0.610 mg/L

OTHER TEST CONDITIONS
- Photoperiod: 16/8 (light/dark) with 20 minute dawn and dusk transition

EFFECT PARAMETERS MEASURED
- Number of mortalities and sub-lethal effects were determined in each test and control vessel at 1, 3, 6, 24, 48, 76 and 96h after the start of the exposure.
- Water temperature, pH and dissolved oxygen: daily. The pH and dissolved oxygen concentration were measured using a Hach Flexi handheld meter whilst the temperature was measured using a Hanna Instruments HI 93510 digital thermometer.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0.7 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks on result:

not determinable

Details on results:

No deaths or sub-lethal effects were observed throughout the test. The test item preparations were observed to be clear colorless solutions over the entire exposure period.

Results with reference substance (positive control):

No positive control was used.

Validity criteria fulfilled:

yes

Conclusions:

The 96-h LC50 value is >0.70 mg/L in rainbow trout (O. mykiss).

Executive summary:

The short-term toxicity to freshwater fish was determined in a limit test according to OECD TG 203 and in compliance with GLP criteria. In this study, groups of 7 rainbow trout (Oncorhynchus mykiss) were exposed to nominal test concentrations of 0 (control), 0 (vehicle control) and 0.87 mg/L for 96 hours under semi-static test conditions. Limit test concentration of 0.87 mg/ was selected based in the presence of an EC50 of 0.87 mg/l. In case of absence of fish mortality at this concentration the Daphnia would be considered the more sensitive species in the risk characterisation. The test concentration was analytically verified, but did not remain within 80 - 120% of the nominal test concentrations. Therefore, the effect value is based on the geometric mean measured concentration, which was calculated to be 0.70 mg/L. Fish mortality and sub-lethal effects were recorded after 3, 6, 24, 48, 72 and 96 hours exposure. No mortality or sub-lethal effects were observed during the test. Based on these findings the 96 h LC50 value was determined at >0.70 mg/L.

Description of key information

The short-term toxicity to freshwater fish was determined in a limit test according to OECD TG 203 and in compliance with GLP criteria. In this study, groups of 7 rainbow trout (Oncorhynchus mykiss) were exposed to nominal test concentrations of 0 (control), 0 (vehicle control) and 0.87 mg/L for 96 hours under semi-static test conditions. Limit test concentration of 0.87 mg/ was selected based in the presence of an EC50 of 0.87 mg/l. In case of absence of fish mortality at this concentration the Daphnia would be considered the more sensitive species in the risk characterisation. The test concentration was analytically verified, but did not remain within 80 - 120% of the nominal test concentrations. Therefore, the effect value is based on the geometric mean measured concentration, which was calculated to be 0.70 mg/L. Fish mortality and sub-lethal effects were recorded after 3, 6, 24, 48, 72 and 96 hours exposure. No mortality or sub-lethal effects were observed during the test. Based on these findings the 96 h LC50 value was determined at >0.70 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.7 mg/L