Diisotridecyl adipate

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.033 µg/L

Assessment factor:

50

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

1 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.003 µg/L

Assessment factor:

500

Extrapolation method:

assessment factor

PNEC marine water (intermittent releases):

1 mg/L

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

48 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

40 mg/kg sediment dw

Assessment factor:

10

Extrapolation method:

assessment factor

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

40 mg/kg sediment dw

Assessment factor:

100

Extrapolation method:

assessment factor

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

1 mg/kg soil dw

Assessment factor:

1 000

Extrapolation method:

assessment factor

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

Some of the available tests were performed using vehicles in order to increase solubility of test substances. As consequence, the effect levels observed are far above the water solubility of the test substance.

Derivation of PNECs is based on ECHA TGD "Guidance on information requirements and chemical safety assessment - Chapter R.10: Characterisation of dose[concentration]-response for environment.

PNEC aqua (freshwater)

For diisotridecyl adipate or alternatively for Bis(-2 -ethylhexyl) adipate as supporting substance, short-term toxicity tests have been performed for three trophic levels: fish (Cyprinodon variegatus), invertebrates (Daphnia magna), and green algae (Pseudokirchnerella subcapitata). E(L)C 50 were: fish > 5000 mg/L, Daphnia > 1000 mg/L. Algae > 100 mg/L.

 

Based on the results of a chronic toxicity study in Daphnia magna with Diisotridecyl adipate (Simon, 2016), the NOEC based on mean cumulative offspring per survivor was equal to 1.64 µg/L (based on the time weighted average (TWA) test concentration of the test medium), which is greater than the level of water solubility. Although the measured water solubility values for DITA are lower than the determined NOEC in the Daphnia study (Simon, 2016) and the study is considered invalid, the value of 1.64 µg/l is used as basis for the PNEC-derivation as long as no new test is available.

Considering the available chronic algae NOErL of >=100 mg/L, according to table R.10.4 of TGD Chapter R.10, an assessment factor of 50 is applied to the NOEC value.

 

PNEC aqua (marine water)

As stated above, the NOEC for aquatic long-term toxicity in Daphnia will be used for derivation of PNEC, as it is lower as the obtained NOErL in an algae study (>=100 mg/l). To the Daphnia NOEC of 1.64 µg/L an assessment factor of 500 according to table R.10.4 of TGD Chapter R.10 is applied.

 

PNEC aqua (intermittent release)

Short- term tests with species of three trophic levels are available. The lowest L(E)C50 of >100 mg/L is used for derivation of PNEC, an assessment factor of 100 according to table R.10.4 of TGD Chapter R.10 is applied.

 

PNEC STP

For the derivation of PNEC STP, an activated sludge respiratory inhibition test (OECD TG 209/EU method C.11) is available. An EC50 and NOEC value have been determined; both reported to be > 480 mg/L (value adjusted for diisotridecyl adipate). According to TGD Chapter R.10 section R.10.4.2 and table R.10-6, assessment factors of 100 or 10 are applied to the EC50 or NOEC values respectively. A NOEC of 480 mg/L and an assessment factor of 10 are used to derive the PNEC STP.

 

PNEC sediment (freshwater)

For the test substance no sediment test is available. A suitable 10-day marine sediment toxicity study on the read across substance diisooctyl adipate obtained and is used to adequately cover this endpoint. The time frame of 10 days is regarded sufficient as DITA is readily biodegradable. The 10 -day LC50 is greater than 12000 mg/kg (dry), the highest concentration tested. The derived NOEC is 4000 mg/kg.

The PNEC sediment (freshwater) was calculated to be 40 mg/kg ww. In general, an assessment factor of 100 is applied to the available long-term data. As DITA is readily biodegradable, the test period of 10 days in the underlying sediment study is regarded sufficient and hence, the assessment factor of 100 is applicable here.

 

 

PNEC sediment (marine water)

For the test substance no sediment test is available. A suitable 10-day marine sediment toxicity study on the read across substance diisooctyl adipates obtained and is used to adequately cover this endpoint. The time frame of 10 days is regarded sufficient as DITA is readily biodegradable. The 10 -day LC50 is greater than 12000 mg/kg (dry), the highest concentration tested. The derived NOEC is 4000 mg/kg.

The PNEC sediment (marine water) was calculated to be 40 mg/kg ww. In general, an assessment factor of 100 is applied to the available long-term data. As DITA is readily biodegradable, the test period of 10 days in the underlying sediment study is regarded sufficient and hence, the assessment factor of 100 is applicable here.

 

PNEC soil

For the test substance no data on soil toxicity is available. Therefore, the earthworm study with the source substance Bis(tridecyl) adipate will be considered for the PNECsoil derivation (LC50 of > 1000 mg/kg soil d. w. after 14 days). The time frame of 14 days in the study is considered sufficient as DITA is readily biodegradable. The PNEC soil was calculated to be 1 mg/kg soil. An assessment factor of 1000 is used with the available LC50 derived in the earthworm toxicity test. As discussed above, the test period is regarded sufficient for PNEC derivation as DITA is readily biodegradable.

 

PNEC oral

Secondary poisoning is not of concern for diisotridecyl adipate. The substance is readily biodegradable and the potential for aquatic bioaccumulation is low (calculated BCF = 14.83) There is no concern about toxic effects resulting from exposure via the food chain.

Conclusion on classification

Acute aquatic toxicity tests on the test item diisotridecyl adipate showed EC50 values > 100 mg/l for all species and trophic levels. The results derived in an algae study and the long term Daphnia studies with DITA and its read-across substances indicate that DITA is not toxic in the range of water solubility. Diisotrdicecyl adipate is readily biodgradable. Therefore the substance is not classified for the environment.