Reaction mass of bis(2-ethylhexyl) adipate and cyclohexyl 2-ethylhexyl adipate and dicyclohexyl adipate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 - 27 Apr 1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A stock solution was prepared by mixing of 500 mg DEHA/L and 100 mg Tween 80/L. The stock solution was stirred for 10 min at 20 °C. The stock solution was diluted with tap water and 100 mg/L Tween 80 to prepare the different test concentrations. 10 mL of the respective test solution was added to the test vessel.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Tween 80
- Concentration of vehicle in test medium (stock solution and final test solution): 100 mg/L

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISMS
- Source: inhouse culture originally obtained by Institut National de Recherche Chimique Appliquee, France
- Method of breeding: photoperiod: 16 h light / 8 h dark , daily feeding with green algae, once (after the change of water) feeding with yeast
- Feeding during test: no

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

2.44 mmol/L

Test temperature:

18 - 20 °C

pH:

7.41 - 7.84

Dissolved oxygen:

6.47 - 9.10 mg/L

Nominal and measured concentrations:

Nominal: 15.62, 31.2, 62.5, 125, 250, 500 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Centrifuge tube with 10 mL test solution
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: filtered (ac) and dechlorinated tap water
- Ca/mg ratio: 4:1
- Conductivity: 570 µS/cm
- Intervals of water quality measurement: at the beginning and the end of the test

OTHER TEST CONDITIONS
- Photoperiod: 16:8 light: dark
- Light intensity: ~ 5 µE/m*m*s

EFFECT PARAMETERS MEASURED : Immobility was recorded after 3, 6, 24 and 48h exposure time.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

250 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

RS-Freetext:
RESULT IMMOBILISATION
EC 50 (3h): > 500 mg/l
EC 50 (6h): > 500 mg/l
EC 50 (24h): > 500 mg/l
EC 50 (48h): > 500 mg/l

immobilised organisms after 48 hours (from 20 organisms / conc.):
nom. conc. (mg/l )   0h	 3h  6h	 24h 48h	
(control)            -	 -   -	 -   -   
(cont. solubilizer)  -	 -   -	 -   -   
 15.62	             -	 -   -	 -   1 
 31.2                -	 -   -	 -   1   
 62.5	             -   -   -   -   1   
125	             -	 -   -	 -   2   
250                  -	 -   -	 -   2   
500                  -	 -   -	 -   5   

RESULTS SYMPTOMS
At concentrations between 100 and 500 mg/l the test organisms swam partly at the surface.

REMARK
Effect concentration is greater than the solubility of the substance in the test medium.

Behavior of the test item during the test: No remarkable observations.

Validity criteria fulfilled:

yes

Conclusions:

A 48h acute toxicity test according to EU method C.2 using Daphnia magna as test organism revealed that DEHA is not acutely harmful to freshwater invertebrates up to the saturation limit in water.

Executive summary:

The study was performed according to EU method C.2 using Daphnia magna as test organism. A stock solution of 500 mg/L was prepared by mixing with 100 mg Tween 80/L. The stock solution was diluted with tap water and 100 mg/L Tween 80 to prepare the different test concentrations. Nominal test concentrations between 15.62 and 500 mg/L were tested. Immobile daphnids were observed after 48h exposure time. A 48h-EC50 is determined to be > 500 mg/L. At concentrations between 100 and 500 mg/L the test organisms swam partly at the surface of the test vessels. Since the effect concentrations are greater than the solubility of DEHA in the test medium, it can be concluded that DEHA is not harmful to freshwater invertebrates up to the saturation limit in water.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Justification for type of information:

Since no studies assessing the short-term toxicity of Reaction mass of Hexanedioic acid, 1-cyclohexyl 6-(2-ethylhexyl) ester, Hexanedioic acid, 1,6-dicyclohexyl ester and Hexanedioic acid, 1,6-bis(2-ethylhexyl) ester to aquatic invertebrates are available, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 Grouping of substances, a read-across to one (CAS 103-23-1) of the three constituents of the multiconstituent substance was conducted.
The three constituents are structurally very similar being diesters of adipic acid with either two cyclohexyl- (CAS 849-99-0, 25%, Sub 1), two 2-ethylhexyl- (CAS 103-23-1, 25%, Sub 2) or one cyclohexyl- and one 2-ethylhexyl-group (CAS 77357-98-3, 50%, Sub 3). This structural similarity leads to similar physico-chemical properties (log Pow: Sub1 = 5.9; Sub 2: 8.94; Sub 3: 7.02; water solubility: sub 1/2/3: < 0.1 mg/L) and subsequently to similar behavior (Sub 1/2/3: predicted to be readily biodegradable) and toxicity pattern in the environment.
Data from CAS 103-23-1 (purity: 100%) was used to assess the ecotoxicity of the multiconstituent in a read across approach. This substance is considered to be a suitable read across substance, since it shows the highest log Pow value of all substances.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Description of key information

No toxicity is observed up to the limit of solubility of the substance in water

Additional information

Since no studies assessing the short-term toxicity of Reaction mass of Hexanedioic acid, 1-cyclohexyl 6-(2-ethylhexyl) ester, Hexanedioic acid, 1,6-dicyclohexyl ester and Hexanedioic acid, 1,6-bis(2-ethylhexyl) ester to aquatic invertebrates are available, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 Grouping of substances, a read-across to one (CAS 103-23-1) of the three constituents of the multiconstituent substance was conducted. The three constituents are structurally very similar being diesters of adipic acid with either two cyclohexyl- (CAS 849-99-0, 25%, Sub 1), two 2-ethylhexyl- (CAS 103-23-1, 25%, Sub 2) or one cyclohexyl- and one 2-ethylhexyl-group (CAS 77357-98-3, 50%, Sub 3). This structural similarity leads to similar physico-chemical properties (log Pow: Sub1 = 5.9; Sub 2: 8.94; Sub 3: 7.02; water solubility: sub 1/2/3: < 0.1 mg/L) and subsequently to similar behavior (Sub 1/2/3: predicted to be readily biodegradable) and toxicity pattern in the environment.

Data from CAS 103-23-1 (purity: 100%) was used to assess the ecotoxicity of the multiconstituent in a read across approach. This substance is considered to be a suitable read across substance, since it shows the highest log Pow value of all substances.

The key study was performed according to EU method C.2 using Daphnia magna as test organism (BASF 1988). A stock solution of 500 mg/L was prepared by mixing with 100 mg Tween 80/L. The stock solution was diluted with tap water and 100 mg/L Tween 80 to prepare the different test concentrations. Nominal test concentrations between 15.62 and 500 mg/L were tested. Immobile daphnids were observed after 48h exposure time. A 48h-EC50 is determined to be > 500 mg/L. At concentrations between 100 and 500 mg/L the test organisms swam partly at the surface of the test vessels. Since the effect concentrations are greater than the solubility of DEHA in the test medium, it can be concluded that DEHA is not acutely harmful to freshwater invertebrates up to the saturation limit in water. Based on the structural similarity this can also considered to be true for the substance to register and is confirmed in a long-term toxicity test with aquatic invertebrates.