Registration Dossier

Ecotoxicological information

Endpoint summary

Currently viewing:

Administrative data

Description of key information

All acute and chronic toxicity information available for DITA resulted in no toxic effects up to the limit of water solubility.

In the acute Daphnia study, toxic effects were seen, but only above the limit of water solubility of DITA. In this study, after exposure to the 100 mg/L and 1000 mg/L Water Accommodated Fraction (WAF), 10 % and 17.5 % immobile Daphnia, respectively, were counted after 48. These effects are considered to be related to physical effects rather than to systemic toxicity. The 48h-EL50 is determined to be > 1000 mg/L based on the loading rates (tested as WAF).

From an algal inhibition test with diisotridecyl adipate as test substance it can be concluded that the ErL50 (24 -72 h) based on the growth rate is > 1000 mg/l nominal loading rate and the NOErL based on the growth rate is100 mg/l nominal loading rate. 

The available long-term toxicity study towards aquatic invertebrates for DITA (Simon, 2016) was conducted by using the column elution method for test medium preparation. Daphnids were exposed to a steady state column eluate in form of the 100% eluate and 10 % eluate for a period of 21 days in a semi-static test design. No significant differences between the control group and the test groups were found for the following endpoints: Mobility, age at first reproduction, length and intrinsic rate. In the undiluted eluate, a ~27% reduction of mean cumulative offspring per surviving daphnids after 21 days were seen, whereas the exposure to the 10%-dilution of the eluate resulted in no significant effects for this endpoint, as well. The concentrations measured in both, the undiluted eluate and the 10%- eluate tests solution, are far above the reported and experimentally determined (e.g. Kotthoff, 2016) water solubility for DITA of ~0.7 µg/L. Hence, micelle formation or other processes causing the inhibition cannot be excluded. Although the measured water solubility values for DITA are lower than the determined NOEC, ≥0.002 mg/L (based on the time weighted average (TWA) test concentration of the test medium) in this study, this value will be used as basis for the PNEC-derivation and hence be taken into account for the environmental exposure assessment. Supported by the available data for the read-across substances (details below) and based on the valid water solubility figure for DITA (0.7 µg/l), this study supports the fact that there is no toxicity in the range of water solubility.

Additional information

Short-term-toxicity to fish

 

The acute lethal toxicity of diisotridecyl adipate to Poecilia reticulata (Guppy) was investigated under static exposure conditions over a period of 96 h. The absence of mortality provides that the LL50 at 96 h is therefore > 100 mg/l (nominal concentration) (Häner/Panolin AG, 1998).

The 96h-LC50 in sheepshead minnow (saltwater) was determined to be > 5000 mg/L for the test substance diisotridecyl adipate (BenKinney/Mobil, 1986).

 

Long-term toxicity to fish

 

Waiving argument:

Long-term toxicity testing of fish does not appear scientifically necessary as data for a more sensitive species of a different trophic level are available (REACH Annex XI Nr. 1). Additionally during the aquatic short-term studies (fish, Daphnia and algae) and the aquatic long-term Daphnia study no toxic symptoms or mortality were observed in the treated group up to the limit of water solubility.

 

Short-term toxicity to aquatic invertebrates

 

Based on the results of the key study it can be concluded that the 24 h and 48 h EL50 values for Daphnia magna of diisotridecyl adipate are >1000 mg/l based on loading rates (Häner/Panolin, 1998).

Long-term toxicity to aquatic invertebrates

 

Chronic aquatic toxicity data (Daphnia magna) are available for DITA itself and the respective read across substances.

The available long-term toxicity study towards Daphnia magna for DITA (Simon, 2016) was conducted by using the column elution method for test medium preparation. Daphnids were exposed to a steady state column eluate in form of the 100% eluate and 10 % eluate for a period of 21 days in a semi-static test design. No significant differences between the control group and the test groups were found for the following endpoints: Mobility, age at first reproduction, length and intrinsic rate. In the undiluted eluate, a ~27% reduction of mean cumulative offspring per surviving daphnids after 21 days were seen, whereas the exposure to the 10%-dilution of the eluate resulted in no significant effects for this endpoint, as well.

The concentrations measured in both, the undiluted eluate and the 10%- eluate tests solution, are far above the reported and experimentally determined (e.g. Kotthoff, 2016) water solubility for DITA of ~0.7µg/L. Hence, micelle formation or other processes causing the inhibition cannot be excluded.

As seen for the read-across substances (details below) and based on the valid water solubility figure for DITA (0.7 µg/l), this study supports the fact that there seems to be no toxicity in the range of water solubility.

There are three long-term toxicity tests with aquatic invertebrates available on the read-across substance bis(2-ethylhexyl) adipate (CAS 103-23-1; DEHA) and one study on the read-across substance diisotridecyl dodecanedioate (CAS 84731-63-5), which show no toxicity in the range of water solubility.

Overall assessment of toxicity towards aquatic invertebrates for DITA

All of these substances, DEHA, DITA and diisotridecyl dodecanedioate, are dialkylesters of dicarboxylic acids, either adipic acid (1,6-hexanedioic acid) or 1,12-dodecandioic acid. Both dicarboxylic acids are linear and have even-numbered carbon chains. The alcohol component of all three substances has branched alkyl groups (C8 or C13). Chronic daphnia data are available for DITA itself and the read across substances with the same acid and a similar alcohol component and the same alcohol component and a similar acid.

Thus, on the basis of the available data it can be concluded that DITA is neither acutely, nor chronically toxic to aquatic invertebrates up to its limit of water solubility.

Toxicity to aquatic algae and cyanobacteria

 

From an algal inhibition test with diisotridecyl adipate as test substance can be concluded that the ErL50 (24 -72 h) based on growth rate is > 1000 mg/l nominal loading rate and the NOErL based on growth rate is ≥ 100 mg/l nominal loading rate.

 

Toxicity to microorganisms

Data for diisotridecyl adipate could not be located. But an activated sludge respiratory inhibition test was conducted with the supporting substance bis-(2 -ethylhexyl) adipate. A NOEC of 350 mg/L was determined (EC50 >350 mg/L) (Huels AG, 1996b).

 

All effect levels determined are far above the water solubility of the test substances. It can be concluded that diisotridecyl adipate does not exhibit toxic effects in aquatic organisms up to its limit of water solubility ( ~ 0.0007 mg/L).