2,2-dimethylpropane-1,3-diyl dibenzoate

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:

other: GLP guideline study without restriction

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:

SAMPLING SCHEDULE:
- Control: at 48 hours (on 2014-08-15)
- Test concentration: 100 mg/L in the freshly prepared media (on 2014-08-13 and 2014-08-14) and in the media after 24 h of exposure (on 2014-08-14 and 2014-08-15) according to the semi static conditions

Vehicle:

no

Details on test solutions:

Pre-TREATMENT OF TEST ITEM AND PREPARATION OF TEST ITEM CONCENTRATION:
- The dilution water was adjusted from pH 8.1 to pH 7.0
- Direct weighings were made to prepare the limit test concentration; 100.3 mg/L (on 2014-08-13) and 100.4 mg/L (on 2014-08-14) of the test item were added to 1 litre of dilution water, treated for 1 h in an ultrasonic bath and afterwards stirred for 2 h on a magnetic stirrer
- Undissolved particles of the test item were removed by filtration using folded filters with a pore size of 7-12 μm
- The pH was measured to be 7.0
- 50 mL of the solution were taken and diluted with 0.5 mL of dilution water containing 5 daphnids resulting in a final concentration of 100 mg/L
- For each test item concentration and the control 4 replicates were prepared

Test organisms (species):

Daphnia magna

Details on test organisms:

- 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:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

13.9 °dH (248 mg/L CaCO3)

Test temperature:

20.7 - 21 °C

pH:

adjusted to pH 7 after day 0 and 1 h

Dissolved oxygen:

8.5 - 8.8 (mg/L)

Salinity:

n.a.

Nominal and measured concentrations:

Effective concentrations ranged from 0.94 % to 1.07 % in the freshly prepared media and from 0.76 % to 0.84 % in the media after 24 hours of exposure.

Details on test conditions:

EXPOSURE CONDITIONS:
- Test vessels: 100 mL glass beakers covered with watch glasses holding 5 neonates in 50 mL of the test medium
- Experimental design: 1 test concentration plus 1 control; 5 neonates per vessel, 4 replicates per concentration/control; no feeding during the exposure period
- Method of initiation: neonates were placed in prepared media
- Photoperiod: 16 h light : 8 h dark
- Temperature of incubation unit: 19.6 to 20.1°C
- Aeration: none
- Test item concentration/s: 100 mg/L
- Method of administration: direct weighing
- Medium renewal: daily
- 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):

not required

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.9 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 0.89 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The results are expressed in terms of geometric mean measured concentrations at 24 h and 48 h.

Validity criteria fulfilled:

yes

Remarks:

(Immobilisation and other abnormalities in the controls did not exceed 10% by the end of the test; dissolved oxygen concentration remained above 3 mg/L throughout the exposure period)

Conclusions:

No toxic effects of of 2,2-dimethylpropane-1,3-diyl dibenzoate against Daphnia were observed at a limit of water solubility under exposure conditions. The results are expressed in terms of geometric mean measured concentrations at 24 h and 48 h. Effective concentrations ranged from 0.94 % to 1.07 % in the freshly prepared media and from 0.76 % to 0.84 % in the media after 24 hours of exposure.

Executive summary:

A study was performed to assess the acute toxicity of 2,2-dimethylpropan-1,3-diyl dibenzoate to Daphnia magna STRAUS under semi 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 limit test concentration of nominally 100 mg/L of 2,2-dimethylpropan-1,3-diyl dibenzoate dissolved in dilution water. Auxiliaries used to prepare the test media were an ultrasonic bath, a magnetic stirrer and folded filters. Observations were made on the swimming ability and the immobilisation rate, respectively, after 24 and 48 hours of exposure.

No toxic effects of 2,2-dimethylpropane-1,3-diyl dibenzoate against Daphnia were observed at a limit of water solubility under exposure conditions. The results are expressed in terms of geometric mean measured concentrations at 24 h and 48 h. This toxicity study is classified as acceptable and satisfies the guideline requirements for the acute Daphnia study.

Description of key information

No toxic effects of 2,2-dimethylpropane-1,3-diyl dibenzoate against Daphnia were observed at a limit of water solubility under exposure conditions. The results are expressed in terms of geometric mean measured concentrations at 24 h and 48 h. Effective concentrations ranged from 0.94 % to 1.07 % in the freshly prepared media and from 0.76 % to 0.84 % in the media after 24 hours of exposure.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.89 mg/L

Additional information

Should read: ">0.89 mg/L"