1,2-Benzenedicarboxylic acid, di-C8-10-alkyl esters

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:

1994-04-13 to 1194-04-15

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report): WITAMOL 118
- Substance type: product
- Physical state: liquid
- Stability under test conditions: no data
- Storage condition of test material: no data
- Other: none

Analytical monitoring:

yes

Details on sampling:

- Concentrations: WAF
- Sampling method: not mentioned
- Sample storage conditions before analysis: not mentioned

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 1 g/L test substance was mixed with synthetic freshwater, stirred for 18 hours and subsequently filtered
- Controls: yes, synthetic freshwater
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): not applicable
- Concentration of vehicle in test medium (stock solution and final test solution): not applicable
- Evidence of undissolved material (e.g. precipitate, surface film, etc): not applicable

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain: Daphnia magna Straus, clone 5
- Source: laboratory breed
- Age at study initiation: not older than 24 hours
- Method of breeding: The females were maintained in M4 medium in 1 L beakers. A reddish dark-brown coloration of the animals indicated that they were healthy. At two to three day intervals, the exuviae were siphoned off and the water was changed. In the course of this, the offspring was removed from the breeding vessels. At regular intervals of approx. 4 weeks, offspring was isolated from the vessels. They served as a basis for further breeding.
- Feeding during test: none



ACCLIMATION
- Acclimation period: Females were seperated from the offspring 24 hours before the start of the test. The offspring produced overnight were transferred into test water and were used for the test.
- Type and amount of food: Scenedesmus subspicatus, the amount of food added is such that it is consumed by the animals
- Feeding frequency: daily

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

none

Hardness:

14 °dH (2.5 mmol Ca2+/Mg2+)

Test temperature:

20 °C ± 1 °C

pH:

7.9 - 8.2

Dissolved oxygen:

8.0 - 8.3 mg/L

Salinity:

CaCl2 x 2 H2O: 294 mg/L; MgSO4 x 7 H2O: 123 mg/L; NaHCO3: 63 mg/L; KCl: 5.5 mg/L
Ca/Mg ratio: 4:1
Na/K ratio: 10:1

Nominal and measured concentrations:

Nominal: 0, WAF
Measured: 0 (control), 4.3 mg/L (geometric mean of measured initial and end concentrations)

Details on test conditions:

TEST SYSTEM
- Test vessel: Round-bottom test tubes
- Material, size, headspace, fill volume: glass, calibrated to 10 mL
- Aeration: none
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: synthetic fresh water (CaCl2 x 2 H2O: 294 mg/L; MgSO4 x 7 H2O: 123 mg/L; NaHCO3: 63 mg/L; KCl: 5.5 mg/L)
- Ca/mg ratio: 4:1
- Conductivity: not mentioned
- Culture medium different from test medium: yes
- Intervals of water quality measurement: not mentioned


OTHER TEST CONDITIONS
- Adjustment of pH: not adjusted
- Photoperiod: not applicable
- Light intensity: no light during test


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobilisation after 24 and 48 hours; O2 concentration, pH at the end of the test


TEST CONCENTRATIONS
- Spacing factor for test concentrations: not mentioned
- Range finding study: not applicable

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 4.3 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

other: DOC content of test material

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 4.3 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

other: DOC content of test material

Basis for effect:

mobility

Details on results:

- Mortality of control: not applicable
- Other adverse effects control: 1/20 (5%) animals immobile
- Abnormal responses: none mentioned
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: none mentioned
- Effect concentrations exceeding solubility of substance in test medium: in the range of water solubility not toxic under test conditions

Results with reference substance (positive control):

- Results with reference substance valid? yes, historical control (not tested in parallel to the test substance)
- Concentrations: 1.0, 2.0 mg/L potassium dichromate
- Results: immobilisation of 15 % at 1.0 mg/L and 100 % at 2.0 mg/L both after 24 h

Reported statistics and error estimates:

not applicable

Table #1: Effect of WITAMOL 118 on immobilisation of Daphnia magna

concentration[mg/L]	24 hour values			48 hour values
	number		%	number		%
	mobile	immobile	immobile	mobile	immobile	immobile
0 (control)	19	1	5	19	1	5
4.3	19	1	5	19	1	5

Validity criteria fulfilled:

yes

Conclusions:

In the range of water solubility not toxic under test conditions.

Executive summary:

The effect of 1,2-Benzenedicarboxylic acid, di-C8-10-alkyl esters (Witamol 118) on the immobilisation of Daphnia magna was studied.

Daphnia magna was exposed to WITAMOL 118 for an exposure time of 48 hours. No immobilisation (=< 10 %) was seen in the concentration of 4.3 mg/L (geometric mean of measured initial and end concentrations, DOC-content of test material). The EC50 was in excess of 4.3 mg/L. Therefore the substance was under test conditions not toxic in the range of water solubility.

Description of key information

The acute toxicity towards daphnids has been investigated over a 48 hour period for different phthalic esters. No toxicity in the range of the water solubility was observed. Entrapment on the surface occurred at higher concentrations, and is regarded as beyond the water solubility of the substance. The EC50 was > 4.3 mg/L for 1,2-Benzenedicarboxylic acid, di-C8 -10 -alkyl esters.

Additional information

The acute toxicity of various phthalate esters was assessed in a number of freshwater invertebrate studies over a 48 hour period. No toxicity was observed up to the limit of water solubility in any of the studies. Entrapment on the surface occurred at higher concentrations, and is regarded as beyond the water solubility of the substance. The EC50 was > 4.3 mg/L for 1,2-Benzenedicarboxylic acid, di-C8 -10 -alkyl esters.

The effect of the structurally related substance 1,2-Benzenedicarboxylic acid, di-C6-10-alkyl esters on the immobilization of Daphnia magna results in no effects up to the highest concentration tested and hence no toxicity in the range of water solubility, with an EC50 > 1.7 mg/l.

Data for the other read-across substances further supports these findings with 1,2-Benzenedicarboxylic acid, diundecyl phthalate resulting in an EC50 > 0.022 mg/l (entrapment on the surface), 1,2-Benzenedicarboxylic acid, dihexyl phthalate exhibiting no acute toxicity up to the limit of water solubility (EC50 >0.18 mg/L), and for 1,2-Benzenedicarboxylic acid, dioctyl phthalate no toxicity was found at any dose up to and including 10 mg/l over an exposure period of 48 hours.