Diisononyl adipate

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

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

Adequacy of study:

key study

Study period:

02 - 16 Aug 1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP guideline study with structurally similar source substance

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
See explainations in the endpoint study summary and the analogue justification document attached in chapter 12.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

865 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 550-1000 mg/kg

Duration:

7 d

Dose descriptor:

LC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

550 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Additional information

Since no study assessing the toxicity of DINA to soil macroarthropods is available, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 Grouping of substances, a read-across to the structurally very similar Bis(2-ethylhexyl) adipate (CAS 103-23-1, DEHA) was conducted. The read across is justified due to the similarity of structure and functional groups and accordingly similar physico-chemical properties which result in similar environmental behavior and fate (see table below).

Substance	Diisononyl adipate	Bis(2-ethylhexyl) adipate
CAS number	33703-08-1	103-23-1
Structure	see attachment	see attachment
Molecular formula	C24H46O4	C22H42O4
Molecular weight	398.63 g/mole	370.58 g/mole
PC parameter
Water solubility	RA to 103-23-1	0.0032 mg/L (EU A.6)
Partition coefficient	9.54 (OECD 117)	8.94 (OECD 117)
Vapour pressure	0.00000002 hPa at 20 °C (calculation)	0.0000003 hPa at 20 °C (calculation)
Environmental fate
Biodegradability	> 90% in 28 days (OECD 301F)	>90% in 28 days (OECD 301F)
Adsorption [log KOC]	5.15 (calculation)	4.56 (calculation)
Hydrolysis	not relevant
Ecotoxicology
Short-term toxicity to fish [96h-LC50]	No toxicity within the limit of water solubility	No toxicity within the limit of water solubility
Long-term toxicity to aquatic invertebrates [NOEC]	-	-
Short-term toxicity to aquatic invertebrates [48h-EC50]	No toxicity within the limit of water solubility	No toxicity within the limit of water solubility
Long-term toxicity to aquatic invertebrates [21d-NOEC]	RA from 103 -23 -1	No toxicity within the limit of water solubility
Short-term toxicity to algae [72h-EC50]	No toxicity within the limit of water solubility	No toxicity within the limit of water solubility
Long-term toxicity to algae [72h-NOEC/EC10]	No toxicity within the limit of water solubility	No toxicity within the limit of water solubility
Toxicity to microorganisms [NOEC]	The inhibition of the degradation activity of activated sludge is not anticipated when DINA is introduced in appropriate low concentrations.	The inhibition of the degradation activity of activated sludge is not anticipated when DEHA is introduced in appropriate low concentrations.

The short-term toxicity test with DEHA was performed according to EU method C.8 using Eisenia foetida as test organisms (Huels 1996). Different nominal concentrations between 100 and 1000 mg/kg d.w. were tested. Mortality was recorded after 7 and 14 days exposure time. Whereas no earthworm died in the control and test concentrations up to 500 mg/kg, 17 animals (out of 40) died in the 1000 mg/kg treatment. Thus, the 14d-LC50 is determined to be 865 mg/kg d.w. based on nominal concentrations.

Based on the mentioned structural similarities between the source and the target substance resulting in a similar efate and ecotoxicological profile this efferct value can also considered to be true for Diisononyl adipate (CAS 33703-08-1) and thus adequately covers this endpoint for the hazard assessment of DINA.