Butanal, reaction products with aniline

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

direct weighings

Vehicle:

no

Details on test solutions:

Aliquots of the samples from the biological test were directly analysed by HPLC and UV/VIS-detection (range of the injection volume: 100 μL, depending on the expected concentration).

Test organisms (species):

Daphnia magna

Details on test organisms:

- Name: Daphnia magna STRAUS, parthenogenetic females
- Source: Strain of Bundesgesundheitsamt Berlin
- Maintenance and Acclimatisation: A population of parthenogenetic females of synchronized age structure has been maintained for more than 15 years in the test facility under constant temperature conditions (20 +/- 1 °C) at a 16 : 8 hour light-dark photoperiod (light intensity: < 20 μE x m-2 x s-1). The culture water (so-called 'M4 medium') was partly renewed once a week. The Daphnia were exclusively fed unicellular green algae (Desmodesmus subspicatus) 'ad libitum'. Mortalities of parent Daphnia during the culture period were recorded daily in a semi-quantitative way. The neonates were separated from their parent Daphnia by filtration prior to the acute test.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

15.1° dH (=270 mg/L CaCO3)

Test temperature:

18-22°C

pH:

7.7

Dissolved oxygen:

8.6 mg/L (= 96 % saturation)

Salinity:

Reconstituted water (so-called 'M4 medium' according to OECD 202) was used for the maintenance of the test animals and the preparation of stock and test solutions of the test item.

Nominal and measured concentrations:

Nominal concentration: 0.63, 1.25, 2.5, 5, 10 and 20 mg/L

Details on test conditions:

Pre-treatment of test item and preparation of test item concentrations:
To produce the different Water Accommodated Fractions (WAFs) 1.3, 2.6, 5.3, 10.7 and 21.3 mg of the test item were added each to 1 litre of dilution water except the lowest test concentration for which 1.4 mg were added to 2 litres of dilution water. All solutions were treated for 60 seconds at 8000 rpm with an ultra turrax and then stirred for 24 h on a magnetic stirrer. Finally undissolved particles of the test item were removed by filtration using aseptic filters (Sartobran 150 sterile capsule) with a pore size of 0.45 + 0.2 μm. The pH was measured to be 7.7 - 7.8.
19 mL of each filtered solution were taken and diluted with 1 mL of dilution water containing 10 daphnids resulting in the final loading rates of 0.63, 1.3, 2.6, 5, 10 and 20 mg/L. For each loading rate and the control 2 replicates were prepared.

Exposure conditions:
Test vessels : 50 mL glass beakers covered with watch glasses, holding 10 neonates in 20 mL of test medium
Experimental design : 6 test concentration plus 1 control
10 neonates per vessel, 2 replicates per concentration/control, no feeding during the exposure period
semi static system
Method of initiation : neonates were placed in prepared media
Photoperiod : 16 h light : 8 h dark
Temperature of incubation unit : 19.9 to 20.3 °C
Aeration : none
Test item concentration/s : 0.63, 1.25, 2.5, 5, 10 and 20 mg/L
Method of administration : direct weighing
Medium renewal : none
Duration of exposure: 48 hours
Criteria of effects : The criterion of adverse effects used in this study was the item-induced alteration of the normal mobility behaviour and the loss of locomotory actions of the neonates, observed at 24 and 48 hours.

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EL50

Effect conc.:

>= 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

3.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 2.1-6.6 mg/L

Details on results:

Butanal, reaction products with aniline has not a definite or unique structure and consists of several constituents. A suitable selective and sensitive chromatographic method for the determination of the test item in aqueous solutions could not be established and an accompanying analysis by the means of a chromatographic method cannot be performed.
Because aniline seems to have an influence on the toxic effects of Butanal, reaction products with aniline, the aniline content was analysed during the test with the sponsor’s agreement. To record the total amount of dissolved substance the content of the test item during the exposure period was additionally verified by DOC determination.
Water Accommodated Fractions (WAFs) were produced to test the effects at different loading rates and all results are expressed in terms of Effective Loadings (EL).

Chemical analysis: HPLC value (aniline) [mg/L]

Test concentration [mg/L]	0 hour	24 hour	48 hour
Control

Validity criteria fulfilled:

yes

Remarks:

The immobilisation and other abnormalities in the controls did not exceed 10 % by the end of the test. The dissolved oxygen concentration remained above 3 mg/L throughout the exposure period.

Conclusions:

The acute toxicity of the substance to Daphnia magna was investigated in a static test. Toxic effects against daphnia were observed at an Effective Loading (48 h EL50) of 3.8 mg/L.

Executive summary:

A study was performed to assess the acute toxicity of the test item to Daphnia magna STRAUS under static conditions.

The study was conducted in accordance with the Council Regulation (EC) No 440/2008, Method C.2 ‘Acute toxicity for Daphnia’ (2008) which is equivalent to OECD Guideline for Testing of Chemicals No. 202 'Daphnia sp., Acute Immobilisation Test' (adopted April 13, 2004).

The Daphnia were exposed to a range of concentrations, nominally 0.63, 1.25, 2.5, 5, 10 and 20 mg/L of the test item dissolved in dilution water. Auxiliaries used to prepare the test media were an ultrasonic bath, a magnetic stirrer and aseptic filters. Observations were made on the swimming ability and the immobilisation rate, respectively, after 24 and 48 hours of exposure. After 48 hours of exposure an EL50 of 3.8 mg/L (nominal) was determined.

The test item has not a definite or unique structure and consists of several constituents. A suitable selective and sensitive chromatographic method for the determination of the test item in aqueous solutions could not be established and an accompanying analysis by the means of a chromatographic method cannot be performed. Because aniline seems to have an influence on the toxic effects of the test item, the aniline content was analysed during the test with the sponsor’s agreement. To record the total amount of dissolved substance the content of the test item during the exposure period was additionally verified by DOC determination. Water Accommodated Fractions (WAFs) were produced to test the effects at different loading rates and all results are expressed in terms of Effective Loadings (EL).

This toxicity study is classified asacceptable and satisfies the guideline requirements for the acute Daphnia study.

Description of key information

The acute toxicity of the substance to Daphnia magna was investigated in a static test. Toxic effects against daphnia were observed at an  Effective Loading (48 h EL50) of 3.8 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

3.8 mg/L

Additional information

The test item has not a definite or unique structure and consists of several constituents. A suitable selective and sensitive chromatographic method for the determination of the test item in aqueous solutions could not be established and analytical monitoring by means of a chromatographic method cannot be performed. As aniline seems to have an influence on the toxic effects the test item, the aniline content was analysed during the test with the sponsor’s agreement. To record the total amount of dissolved substance the content of the test item during the exposure period was additionally verified by DOC determination. Water Accommodated Fractions (WAFs) were produced to test the effects at different loading rates and all results are expressed in terms of Effective Loadings (EL).