Carboxylic acids, di-, C5-9

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 - 27 Nov 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

2004

Deviations:

yes

Remarks:

The pH was 5.28 and 5.31 at the highest test concentration and therefore below the recommended range of 6 - 9.

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1010 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Version / remarks:

1996

GLP compliance:

yes (incl. QA statement)

Remarks:

National Institute of Pharmacy and Nutrition, Budapest, Hungary

Test material

Test material information

Constituent 1

Reference substance name:

Carboxylic acids, di-, C5-9

EC Number:

701-329-9

Molecular formula:

C5di: C5H8O4 C6di: C6H10O4 C7di: C7H12O4 C8di: C8H14O4 C9di: C9H16O4

IUPAC Name:

Carboxylic acids, di-, C5-9

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: control and all test concentration levels at the beginning and at the end of the experiment
- 2 mL aliquots
- Sample storage conditions before analysis: kept at -15°C

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: a saturated solution method (water accommodated fraction, WAF) was used, test item solutions were prepared individually by dispersing/dissolving the amount of test item into the test medium (ISO Medium) two days before the start of the experiment, shaken for about 24 hours at approximately 30°C, equilibrated for about 24 hours at approximately 20°C and non-dissolved test material was removed by filtration (0.22 µm) to give the appropriate WAF solutions.
- Differential loading: yes
- Controls: dilution water only
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): test item was stable in media

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Age at study initiation (mean and range, SD): < 24 hours
- Source: István Szent University, Gödöllő, Hungary
- Feeding during test : no

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

248 mg/L (as CaCO3)

Test temperature:

20.5 - 20.7°C

pH:

5.28 - 7.36

Dissolved oxygen:

7.1 - 8.9 mg/L

Nominal and measured concentrations:

Nominal loading rate: 6.25, 12.5, 25.0, 50.0 and 100.0 mg/L
Mean measured loading rate: 6.67, 12.80, 26.23, 47.80 and 94.54 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers
- Fill volume: at least 5 mL test solution/animal
- 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: reconstituted water (ISO medium, according to OECD 202)
- Culture medium different from test medium: no
- Intervals of water quality measurement: water temperature (at the start and at the end of the test in one test vessel at the control), oxygen concentration, pH (in one test vessel at all concentration levels at the start and at the end of the test),

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16:8 hours light:dark

EFFECT PARAMETERS MEASURED: immobility or mortality (24 and 48 hours after test start)

RANGE-FINDING STUDY
- Test concentrations: control, 0.1, 1.0, 10, 100 mg/L (nominal loading rate WAF)
- Results used to determine the conditions for the definitive study: Number of treated/ immobilized animals: 10 / 0 (control), 10 / 0 (0.1 mg/L), 10 / 0 (1.0 mg/L), 10 / 0 (10 mg/L), 10 / 10 (100 mg/L)

Reference substance (positive control):

yes

Remarks:

Potassium dichromate is tested at least twice a year

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

55.73 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Remarks on result:

other: 95%-confidence limits: 51.79 – 59.96 mg/L

Results with reference substance (positive control):

EC50: 0.82 mg/L, (95 % confidence limits: 0.66 – 0.93 mg/L), 05 - 06 September 2019

Reported statistics and error estimates:

EL50/EC50 values of the test item were calculated using Probit analysis by TOXSTAT software. The 48 hours EL100/EC100 values of the test item were determined directly from the raw data. For the determination of the LOELR/LOEC and NOELR/NOEC, the immobilization at the test concentrations was tested on significant differences to the control values by Dunnett’s Test (α = 0.05) using TOXSTAT software.

Any other information on results incl. tables

Table 1: Number and percentage of immobilised animals

 

Nominal loading rate WAF [mg/L]	Number of treated animals		Immobilised animals
		24 hours		48 hours
		number	percent	number	percent
Control	20	0	0	0	0
6.25	20	0	0	0	0
12.5	20	0	0	0	0
25.0	20	1	5	1	5
50.0	20	2	10	5*	25
100.0	20	20*	100	20*	100

* : statistically significantly different compared to the control values (Dunnett’s Test;a= 0.05)

Table 2: Calculation of exposure concentrations

 

Concentration (mg/L nominal loading rate WAF)	Measured concentrations (mg/L)		Geometric mean
	0h/start	48h/end	mg/L
6.25	6.73	6.62	6.67
12.5	12.60	13.00	12.80
25.0	25.73	26.73	26.23
50.0	47.17	48.43	47.80
100.0	93.20	95.90	94.54

Table 3: Validity criteria for OECD 202

Criterion from the guideline	Outcome	Validity criterion fulfilled
In the control, including the control containing the solubilising agent, not more than 10% of the daphnids should have been immobilized.	0%	yes
The dissolved oxygen concentration at the end of the test should be ≥ 3 mg/L in control and test vessels.	> 3 mg/L	yes

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

For further details please refer to “Any other information on results incl. tables”.