Butanedioic acid, sulfo-, 4-C12-14 (even numbered)-alkyl esters, disodium salts

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Study period:

2014

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH


1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The read across is justified by the similar structures, common functional groups and similar C-chain lengths of both substances (Scenario 4.1 and 5.2 of the Read-Across Assessment Framework (RAAF) with Considerations on multi-constituent substances and UVCBs, 2017). Furthermore, the two substances have a similiar ecotoxicological profile with lower toxicity to daphnids of the registered target substance when compared to the read across source substance. Since the source substance has higher acute Daphnia toxicity, the read across is conservative when using the obtained data. There is no indication that specific MoA like endocrine disruption etc. are relevant for the (eco)toxicity are relevant for both the source and target substance.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Source and target substance structures are described in detail in the attached read across justification document for the monoester group. Both substances differ mainly by the C-Chain length.

3. ANALOGUE APPROACH JUSTIFICATION
As described above, the two substances have a similiar ecotoxicological profile with lower toxicity (about a factor of 3) to daphnids of the registered target substance when compared to the read across source substance. Since the source substance has higher acute Daphnia toxicity, the read across is conservative when using the obtained data from the source substance.

4. DATA MATRIX
See attached read across justification document (section 13 of the IUCLID file).

Reason / purpose for cross-reference:

read-across source

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

1.1 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: 95%CI 0.27 – 1.49 mg/L

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

1.6 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Remarks on result:

other: 95% CI 0.38 - 1.86 mg/L

Duration:

21 d

Dose descriptor:

EC10

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth

Remarks on result:

other: No adverse effect observed

Details on results:

- Mortality of parent animals: yes, used for EC10 calculation.In the control and up to and including the test concentration of 0.55 mg/L, the survival of the test animals at the end of the test was 100%. In the two highest test concentrations mortality was observed, 10% at 1.1 mg/L and 60% at 2.2 mg/L.
- No. of offspring produced per day per female:The mean reproduction rate of the daphnids in the control was 125 ± 24 living offspring per reproductive adult (mean ± standard deviation.No statistically significant inhibitory effect of the test item on the mean reproduction rate was determined up to and including the highest test concentration of 2.2 mg/L. The EC10 for the mean reproduction rate was calculated to be at 1.6 mg/L (confidence limits: 0.38-1.86 mg/L).
- Body length and weight of parent animals: The mean body length of the daphnids in the control was 4.1 ± 0.04 mm (mean ± standard deviation). No statistically significant inhibitory effect of the test item on the mean body length was determined up to and including the highest test concentration of 2.2 mg/L.
- Type and number of morphological abnormalities: no visible abnormalities were observed at the test animals during the test
- Type and number of behavioural abnormalities: no visible abnormalities were observed at the test animals during the test
- Effect concentrations exceeding solubility of substance in test medium: none

- Analytical results: In the biologically relevant dose groups, the measured test item concentrations in the freshly prepared test media of the nominal concentrations of 0.55 to 2.2 mg/L were between 89 and 112% of the nominal values at the start of the test medium renewal periods. In the aged test media samples without food, the measured concentrations as % nominal were between 83 and 104%. Therefore, the biological results were based on nominal concentrations.

The read across is justified by the similar C-chain lengths of both substances and lower ecotox and especially Daphnia toxicity of the registered target substance when compared to the read across source substance. Since the source substance has higher acute Daphnia toxicity, the read across is conservative when using the obtained data.

Reported statistics and error estimates:

The mean reproduction rates and mean body lengths of the daphnids at the test concentrations were both compared to the control by multiple Williams t-tests, one-sided smaller, alpha = 0.05. Additionally, the EC10 for the inhibition of the reproduction rate and the immobility after 21 days was calculated by Probit Analysis using linear maximum likelihood regression.

After 21 days 0, 0, 0, 0, 10 and 60% mortality was observed in the control and at nominal test concentrations of 0.1375, 0.275, 0.55, 1.1 and 2.2 mg/L, respectively.

The reproduction per parent daphina was 124.6 (10), 145.6 (10), 126.9 (10), 131.7 (10), 127.0 (10), and 98.6 (10) living offspring per parental animal

(number of parental daphinds used to calculate the mean are given in brackets) in the control and 0.1375, 0.275, 0.55, 1.1 and 2.2 mg/L, respectively

.

Summary of the results after 21 days of exposure of the test animals

	Control	Nominal test item concentrations [mg/L]
		0.1375	0.275	0.55	1.1	2.2
Mortality [%] after 21 days of exposure	0	0	0	0	10	60
Mean reproduction rate (living offspring per adult)	124.6	145.6	126.9	131.7	127.0	98.6
Mean reproduction rate in % of control	100.0	116.9	101.8	105.7	101.9	79.1
Mean body length of the adults [mm]	4.12	4.12	4.05	4.10	4.17	4.19
Mean body length of the adults in % of control	100.0	100.0	98.4	99.6	101.2	101.7

 

The biological results can be summarized as follows (on the basis of nominal concentrations of the test item

Parameter	Inhibition of reproduction rate	Immobility	Inhibition of growth
	(21 days)	(21 days)
EC10  [mg/L]	1.6	1.1	n.d.
95% confidence interval	0.38 - 1.86	0.27 – 1.49	n.d.

 

n.d.: could not be determined, due to lack of inhibitory effects

 

):

Validity criteria fulfilled:

yes

Conclusions:

21-day EC10: 1.1 mg/L

Executive summary:

In the Klimisch 1 GLP study from Eckenstein (2015) the chronic toxicity of Sulfosuccinic (FA C12-18)E, 2Na on Daphnia magna was determined in an 21 day semi-static test according to OECD 211. The test was performed with concentrations of 0.1375, 0.275, 0.55, 1.1, and 2.2 mg Sulfosuccinic (FA C12-18)E, 2Na /L and a blank control. Ten replicates with 1 Daphnia each were set up. After 21 days 0, 0, 0, 0, 10, 60 and 100% mortality was observed in the control and at nominal test concentrations of 0.1375, 0.275, 0.55, 1.1, and 2.2 mg Sulfosuccinic (FA C12-18)E, 2Na /L, respectively.

The reproduction per parent daphina was 124.6 (10), 145.6 (10), 126.9 (10), 131.7 (10), 127.0 (10), and 98.6 (10) living offspring per parental animal (number of parental daphinds used to calculate the mean are given in brackets) in the control and 0.1375, 0.275, 0.55, 1.1 and 2.2 mg/L, respectively.

 

In the biologically relevant dose groups, the measured test item concentrations in the freshly prepared test media of the nominal concentrations of 0.55 to 2.2 mg/L were between 89 and 112% of the nominal values at the start of the test medium renewal periods. In the aged test media samples without food, the measured concentrations as % nominal were between 83 and 104%. Therefore, the biological results were based on nominal concentrations.

 

The EC10 for mortality is 1.1 mg/L, the EC10 for reproduction is 1.6 mg/L. Length was not affected. For the risk assessment, the more conservative EC10, i.e., the EC10 for mortality was used.

 

The result is considered relevant and reliable for the risk assessment.

The read across is justified by the similar C-chain lengths of both substances and lower ecotox and especially Daphnia toxicity of the registered target substance when compared to the read across source substance. Since the source substance has higher acute Daphnia toxicity, the read across is conservative when using the obtained data.

Description of key information

21-day EC10: 1.1 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC10

Effect concentration:

1.1 mg/L

Additional information

In the Klimisch 1 GLP study from Eckenstein (2015) the chronic toxicity of Sulfosuccinic (FA C12-18)E, 2Na on Daphnia magna was determined in an 21 day semi-static test according to OECD 211. The test was performed with concentrations of 0.1375, 0.275, 0.55, 1.1, and 2.2 mg Sulfosuccinic (FA C12-18)E, 2Na /L and a blank control. Ten replicates with 1 Daphnia each were set up. After 21 days 0, 0, 0, 0, 10, 60 and 100% mortality was observed in the control and at nominal test concentrations of 0.1375, 0.275, 0.55, 1.1, and 2.2 mg Sulfosuccinic (FA C12-18)E, 2Na /L, respectively.

The reproduction per parent daphina was 124.6 (10), 145.6 (10), 126.9 (10), 131.7 (10), 127.0 (10), and 98.6 (10) living offspring per parental animal (number of parental daphinds used to calculate the mean are given in brackets) in the control and 0.1375, 0.275, 0.55, 1.1 and 2.2 mg/L, respectively

 

In the biologically relevant dose groups, the measured test item concentrations in the freshly prepared test media of the nominal concentrations of 0.55 to 2.2 mg/L were between 89 and 112% of the nominal values at the start of the test medium renewal periods. In the aged test media samples without food, the measured concentrations as % nominal were between 83 and 104%. Therefore, the biological results were based on nominal concentrations.

 

The EC10 for mortality is 1.1 mg/L, the EC10 for reproduction is 1.6 mg/L. Length was not affected. For the risk assessment, the more conservative EC10, i.e., the EC10 for mortality was used.

 

The result is considered relevant and reliable for the risk assessment.