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

Sediment toxicity

Link to relevant study record(s)

Reference

Endpoint:

sediment toxicity: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-02-22 to 2017-03-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 218 (Sediment-Water Chironomid Toxicity Test Using Spiked Sediment)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Tightly closed, at a dry and good ventilated place
- Solubility and stability of the test substance in the solvent/vehicle: Not applicable

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: None.

Analytical monitoring:

yes

Details on sampling:

SEDIMENT
- Concentrations: 1000 mg/kg dw
- Sampling interval: days 0, 7 and 28
- Sample storage before analysis: Prepared samples were stored in an autosampler at room temperature until analysis.

PORE WATER
- Concentrations: 1000 mg/kg dw
- Sampling interval: days 0, 7 and 28
- Sample storage before analysis: Prepared samples were stored in an autosampler at room temperature until analysis.

OVERLYING WATER
- Concentrations: 1000 mg/kg dw
- Sampling interval: days 0, 7 and 28
- Sample storage before analysis: Prepared samples were stored in an autosampler at room temperature until analysis.

Vehicle:

yes

Details on sediment and application:

PREPARATION OF SPIKED SEDIMENT
- Pooling or mixing of different substrates: For spiking the sediment of the limit test concentration and the solvent control, 40 mL of the corresponding spiking solution and solvent was transferred to 240 g quartz sand. The dispersed test item was thoroughly mixed with the quartz sand with a spatula. Afterwards, the solvent was evaporated for approximately 1 hour. Subsequently, 40 g of the treated quartz sand was weighed out and used for test item analysis on study day -2. Thereafter, the remaining amount of the prepared quartz sand (200 g) was thoroughly mixed into the pre-moistened sediment (moisture of 25 to 30 %) to ensure a homogenous distribution of the test item.
- Controls: Solvent control included
- Chemical name of vehicle: Acetone
- Evaporation of vehicle before use: Approximately 1 hour

Test organisms (species):

Chironomus riparius

Details on test organisms:

TEST ORGANISM
- Common name: Harlequin fly
- Source: In-house culture, originally received from AQUATIC RESEARCH ORGANISMS INC, Hampton NH 03843, USA
- Breeding conditions: 20 +/- 2°C, 500 - 1000 lx, 16 h photoperiod daily.
- Age of animals at beginning of exposure: First larval stage (3 days old)
- Feeding during test
- Food type: TetraMin® flakes
- Amount: 0.25 - 1.0 mg per day and larva
- Frequency: at least 3 times per week

Study type:

laboratory study

Test type:

static

Water media type:

freshwater

Type of sediment:

artificial sediment

Limit test:

yes

Duration:

28 d

Exposure phase:

total exposure duration

Hardness:

180 mg CaCO3/L

Test temperature:

20 ± 2°C

pH:

7.70

Dissolved oxygen:

> 60% of air saturation value

Nominal and measured concentrations:

1000 mg/kg dw

Details on test conditions:

TEST SYSTEM
- Test container (material, size): Glass, 1L (9cm inner diameter)
- Sediment surface per larvae: approx. 3cm²
- Weight of sediment per vessel: 180 g dry weight per vessel
- Overlying water volume: 550 ml
- Depth of sediment and overlying water: 1:4 ration, 2cm sediment layer
- Aeration: yes

EXPOSURE REGIME
- No. of organisms per container (treatment): 20
- No. of replicates per treatment group: 6 + 2 additional beakers for the analytical evaluation
- No. of replicates per control / vehicle control: 6 + 2 additional beakers for the analytical evaluation
- Feeding regime: Daily

- Type and preparation of food: TetraMin® flake food, TETRA
- Amount of food: 0.25 - 1.0 mg fish food per day and larva, depending on the developmental stage

RENEWAL OF OVERLYING WATER
No renewal

OVERLYING WATER CHARACTERISTCS
- Type of water: Medium M4, according to ELENDT (1990)
- Total hardness: 180 mg CaCO3/L
- pH: 7.7

CHARACTERIZATION OF ARTIFICIAL SEDIMENT
- 4 % peat, air dried and finely ground (AURICH-WIESMOOR-TORFVERTRIEB GMBH, D-26639 Wiesmoor)
- 20 % kaolin, kaolinite content preferably > 30 % (ZIEGLER & CO. GMBH, D-95621 Wunsiedel)
- 76 % quartz sand, sand with > 50 % particles sized 50-200 µm (DÖRENTRUP QUARZ GMBH, D-31089 Duingen)
- 0.35 % CaCO3, (ROTH)
- The pH of the sediment was 6.86. Adjustment of the pH value was not necessary.
- The organic carbon content of the final mixture was 2.13%

OTHER TEST CONDITIONS
- Photoperiod: 16h daily
- Light intensity: 500 – 1000 lx

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Development time and the total number of fully emerged male and female midges

VEHICLE CONTROL PERFORMED: yes/no

TEST CONCENTRATIONS
- Spacing factor for test concentrations:
- Justification for using less concentrations than requested by guideline:
- Range finding study
- Test concentrations:
- Results used to determine the conditions for the definitive study:

Reference substance (positive control):

yes

Remarks:

A reference item study with potassium chloride is performed once per year. The results of the most recent test are included in the underlying study report.

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

development rate

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg sediment dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

emergence rate

Details on results:

- Mortality of test animals at end of exposure period:
- Total mass of test animals at beginning of test:
- Changes in body weigthH58 of live adults (% of initial weight) at end of exposure period:
- No. of offspring produced:
- No. of emerged male and female midges (per vessel and per day):
- No. of pupae failing to emerge (per vessel and per day):
- Percent emergence per replicate and test concentration:
- Mean development rate of fully emerged midges (per replicate and treatment rate; male and female midges pooled):
- Mean individual dry weight of larvae (per larvae and per instar):
- Number of living worms per replicate:
- Number of dead worms per replicate:
- Total biomass per replicate:
- Morphological abnormalities:
- Behavioural abnormalities:
- Other biological observations:

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Limit test: No
- Dose-response test: 5 – 7.5 – 11.3 – 16.9 – 25.3 g/kg DW (factor of 1.5).
- EC50: 11.1 mg/l

Emergence Rate and Development Rate, Mortality and Statistical Significance, Emergence and Ratio of Sexes
Nominal concentration of the test item [mg/kg sediment DW]	Replicate	Males (m)	Females (f)	Ratio          (Σm/Σf)	Total Midges	Emergence Rate			Mortality	Development
						[%]	arcsin	Significance compared to control	[%]	Rate	Significance compared to control
Control	1	8	12		20	100	1,5708	-	0	0,0634	-
	2	7	12		19	95	1,3453		5	0,0631
	3	7	13		20	100	1,5708		0	0,0638
	4	11	9		20	100	1,5708		0	0,0633
	5	12	7		19	95	1,3453		5	0,0628
	6	11	9		20	100	1,5708		0	0,0639
	Mean ± SD	9.33 ± 2.25	10.3 ± 2.34	0.90	19.7 ± 0.52	98.3 ± 2.58	1.50 ± 0.116		1.67 ± 2.58	0.0634 ± 0.0004
	CV [%]	24.1	22.7	-	-	2.62	7.76	-	155	0.63	-
Solvent control	1	9	11		20	100	1,5708	no	0	0,0616	no
	2	6	14		20	100	1,5708		0	0,0626
	3	9	11		20	100	1,5708		0	0,0615
	4	9	11		20	100	1,5708		0	0,0626
	5	6	13		19	95	1,3453		5	0,0615
	6	11	9		20	100	1,5708		0	0,0636
	Mean ± SD	8.33 ± 1.97	11.5 ± 1.76	0.72	19.8 ± 0.41	99.2 ± 2.04	1.53 ± 0.092		0.83 ± 2.04	0.0622 ± 0.0009
	CV [%]	23.6	15.3	-	-	2.06	6.0	-	246	1.45	-
1000	1	13	7		20	100	1,5708	no	0	0,0611	no
	2	11	8		19	95	1,3453		5	0,0620
	3	12	8		20	100	1,5708		0	0,0615
	4	13	6		19	95	1,3453		5	0,0617
	5	15	5		20	100	1,5708		0	0,0617
	6	9	11		20	100	1,5708		0	0,0612
	Mean ± SD	12.2 ± 2.04	7.50 ± 2.07	1.62	19.7 ± 0.52	98.3 ± 2.58	1.50 ± 0.116		1.67 ± 2.58	0.0615 ± 0.0003
	CV [%]	16.8	27.6	-	-	2.62	7.8	-	155	0.49	-
Midge Emergence at Day 11-19 after Application
Nominal concentration of the test item [mg/kg sediment DW]	Replicate	Number of midges emerged at observation time (male/female) [days]
		11	12	13	14	15	16	17	18	19
Control	1	0/0	0/0	0/0	0/0	2/2	5/3	1/4	0/3	0/0
	2	0/0	0/0	0/0	0/0	1/1	6/5	0/3	0/2	0/1
	3	0/0	0/0	0/0	0/0	4/0	2/8	1/3	0/1	0/1
	4	0/0	0/0	0/0	0/0	4/0	4/5	1/2	2/2	0/0
	5	0/0	0/0	0/0	1/0	1/0	7/2	3/2	0/2	0/1
	6	0/0	0/0	0/0	0/0	3/1	5/4	3/3	0/1	0/0
Solvent control	1	0/0	0/0	0/0	0/0	3/1	1/4	3/2	1/1	1/3
	2	0/0	0/0	0/0	0/0	1/0	3/6	2/7	0/1	0/0
	3	0/0	0/0	0/0	0/0	1/0	6/4	1/2	1/3	0/1
	4	0/0	0/0	0/0	0/0	5/0	1/4	2/4	1/1	0/2
	5	0/0	0/0	0/0	0/0	1/2	2/5	3/2	0/1	0/1
	6	0/0	0/0	0/0	1/0	3/0	5/3	1/4	1/2	0/0
1000	1	0/0	0/0	0/0	0/0	0/0	5/0	7/5	1/2	0/0
	2	0/0	0/0	0/0	0/0	2/1	5/1	3/2	1/3	0/1
	3	0/0	0/0	0/0	0/0	1/0	5/2	5/2	1/4	0/0
	4	0/0	0/0	0/0	0/0	1/0	4/3	6/1	2/2	0/0
	5	0/0	0/0	0/0	0/0	1/0	6/2	5/1	3/2	0/0
	6	0/0	0/0	0/0	0/0	0/0	6/4	1/3	2/2	0/2

Validity criteria fulfilled:

yes

Remarks:

The study was performed according to the OECD Guideline 218 and GLP Guidelines. The study met all validity criteria.

Conclusions:

No statistical significant differences were found in the limit test item concentration compared to the pooled controls (Emergence) or solvent control (Development Rate). Therefore, the NOEC for the emergence ratio and the development rate was equal to, or higher respectively, than the nominal concentration of the test item of 1000 mg/kg sediment dry weight.

Executive summary:

The toxicity of 1,2 -Benzenedicarboxylic acid, di-C8 -10 -alkyl esters towards freshwater sediment organisms(Chironomus riparius)was assessed in an OECD test guideline 218 study . A limit test with spiked sediment was conducted resulting in a NOEC of ≥ 1000 mg/kg dw for both, the emergence rate and the development rate.

The limit test was conducted by spiking the sediment layer with a nominal test item concentration of 1000 mg/kg sediment dry weight. 140 first instar larvae were exposed to the limit test concentration and to the controls (7 replicates with 20 larvae each, 6 for the biological part and one for the analytical part on day 7, respectively). Water quality parameters such as temperature, pH-value and O2-content were determined regularly throughout the study. Also, ammonium and total hardness were analysed at the day of application before insertion of larvae (day 0) and at test end (day 28) from the control sediment, solvent control sediment and the limit test item group.

Quartz sand samples of the limit concentration (1000 mg/kg dry weight), the control and the solvent control were analytically verified via LC-MS/MS on day -2.  The samples of the water layer, the pore water and the sediment of the test item were analytically verified via LC-MS/MS on day 0, day 7 and day 28 of the limit concentration, the control and the solvent control.

The recoveries of all components of the test item for the treated quartz sand samples on day -2 were in the range of 93% to 101% of the nominal values.

The concentrations of the sediment samples during the test of all components of the test item at day 0 were in the range of 90% to 111% of the nominal values. At day 7 the concentrations of all components of the test item were in the range of 51% to 73% of the nominal and at day 28 the concentrations of all components of the test item were in the range of 70% to 93% of the nominal values.

In the water layer and the pore water samples, the concentrations were constantly at 0% or < LOQ during the test.

In the control, emergence of the midges started 14 days after larvae insertion and was finished at day 19 after larvae insertion with an emergence ratio of 98 %. In the solvent control, emergence of the midges started 14 days after larvae insertion and was finished at day 22 after larvae insertion with an emergence ratio of 99 %.  In the limit test item concentration of 1000 mg/kg sediment dry weight, emergence of the midges started 15 days after larvae insertion and was finished at day 19 after larvae insertion with an emergence ratio of 98 %.

All effect values are given based on the nominal test item concentration. All validity criteria were met throughout the study.

Description of key information

The toxicity of 1,2 -Benzenedicarboxylic acid, di-C8 -10 -alkyl esters towards freshwater sediment organisms (Chironomus riparius) was assessed in an OECD test guideline 218 study . A limit test with spiked sediment was conducted resulting in a NOEC of ≥ 1000 mg/kg dw for both, the emergence rate and the development rate.

Key value for chemical safety assessment

EC10, LC10 or NOEC for freshwater sediment:

1 000 mg/kg sediment dw