4-(1-methyl-1-phenylethyl)-N-[4-(1-methyl-1-phenylethyl)phenyl]aniline

Endpoint summary

Description of key information

The substance is not considered to be persistent within the environment. 

Additional information

Ready biodegradation.

The biodegradability of the test substance was assessed using two different methods:

Method A - Carbon dioxide (CO2) evolution - Modified Sturm test

Method B - Closed bottle test (two-phase closed bottle test)

 

Based on the results of the biodegradability tests using the method of determination of evolved carbon dioxide(method A)and the closed bottle test (two-phase closed bottle test)(method B), the following biodegradability values were established for the test substance after 28 days:

Dt = 29% (method A)

DThOD = 5% (method B)

 

The test substance under the test conditions (method A) and (method B), cannot be considered to be readily biodegradable (D < 60%).

 

 Results from simulation testing on degradation in soil;

In accordance with ECHA Decision number: CCH-D-2114494377-34-01/F, the following studies were conducted for environmental fate:

• Soil simulation testing (Annex IX, Section 9.2.1.3.; test method: Aerobic and anaerobic transformation in soil, EU C.23./OECD TG 307) at a temperature of 12 °C with the registered substance;

The results of this study are as follows:

The output values for the chosen model for each test system are presented in the table below.

Soil type	Model	r^2	χ^2(%)	DT90 at 12°C (days)	DT50 at 12°C (days)
Soil I	SFO	0.9288	13	88.4	26.6
Soil II	SFO	0.8996	8.12	263	79.3
Soil III	HS	0.9583	4.98	498	102
Soil IV	HS	0.9886	3.45	158	88.4

 

[¹⁴C]4-(1-methyl-1-phenylethyl)-N-[4-(1-methyl-1-phenylethyl)phenyl]aniline disappeared over time in all soils, with DT_{50 ­}values of 26.6, 79.3, 102 and 88.4 days in Soils I, II, III and IV respectively.

Almost no mineralisation occurred, with < 2% measured in all soils over 120 days.

10%, 12%, 14% and 4% of applied radioactivity remained in the soil residue for Soils I, II, III and IV respectively at Day 120 after all extractions had been carried out.  ‘Harsh’ ASE extractions removed less than 2% of applied radioactivity.  Therefore, these residues are not considered to be bioavailable and binding to soils was considered a pathway for disappearance.

(c) Results from simulation testing on degradation in sediment;

In accordance with ECHA Decision number: CCH-D-2114494377-34-01/F, the following studies were conducted for environmental fate:

• Sediment simulation testing (Annex IX, Section 9.2.1.4.; test method: Aerobic and anaerobic transformation in aquatic sediment systems, EU C.24./OECD TG 308) at a temperature of 12 °C with the registered substance

The results of this study are as follows:

The output values for the chosen model for each test system are presented in the table below.

Test system	Compartment	Model	r^2	χ^2(%)	DT90 at 12°C (days)	DT50 at 12°C (days)
HOC	Overlying water	SFO	0.9967	7.36	11.1	3.35
	Sediment extracts	HS	0.9938	5.94	90.2	43.2
	Total system	HS	0.9969	3.51	82.2	37.5
LOC	Overlying water	SFO	1.0000	nd	43.9	13.2
	Sediment extracts	SFO	0.6990	23.2	165	49.7
	Total system	SFO	0.7792	20.1	135	40.6

nd: not determined

[¹⁴C]4-(1-methyl-1-phenylethyl)-N-[4-(1-methyl-1-phenylethyl)phenyl]aniline dissipated over time from the water phase to the sediment phase in both sediment types, with overlying water DT_{50 ­}values of 3.35 and 13.2 days in the HOC and LOC test systems respectively.  [¹⁴C]4-(1-methyl-1-phenylethyl)-N-[4-(1-methyl-1-phenylethyl)phenyl]aniline degraded more rapidly in the HOC sediment than the LOC sediment, with total system, reflected in the total system DT₅₀ values of 37.5 and 40.6 days respectively.

Almost no mineralisation occurred, with <1% measured in both the HOC and LOC systems on Day 101.

8.8% and 7.6% of applied radioactivity remained in the sediment on Day 101 as bound radioactivity in the HOC and LOC test systems respectively after all extractions had been carried out.  ASE extractions removed less than 10% of applied radioactivity.  Therefore, these residues are not considered to be bioavailable and binding to sediments was considered a pathway for disappearance.

(d) Other information, such as information from field studies or monitoring studies, provided that its suitability and reliability can be reasonably demonstrated.

Assessment of the propensity of the substance to abiotically degrade is available and is as follows:

Method

Results

according to guideline OECD Guideline 111 (Hydrolysis as a Function of pH) ; according to guideline EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH) ; according to guideline EPA OPPTS 835.2120 (Hydrolysis of Parent and Degradates as a Function of pH at 25°C)

Half-life (DT50): t1/2 (pH 4): 53 d at 20°C; Type: (pseudo-)first order (= half-life) t1/2 (pH 4): 26 d at 25°C; Type: (pseudo-)first order (= half-life) t1/2 (pH 4): 25 h at 50°C; Type: (pseudo-)first order (= half-life) t1/2 (pH 4): 11 h at 60°C; Type: (pseudo-)first order (= half-life) t1/2 (pH 7): 25 d at 20°C; Type: (pseudo-)first order (= half-life) t1/2 (pH 7): 14 d at 25°C; Type: (pseudo-)first order (= half-life) t1/2 (pH 7): 24 h at 50°C; Type: (pseudo-)first order (= half-life) t1/2 (pH 7): 16 h at 60°C; Type: (pseudo-)first order (= half-life) t1/2 (pH 9): 18 d at 25°C; Type: (pseudo-)first order (= half-life) t1/2 (pH 9): 34 d at 20°C; Type: (pseudo-)first order (= half-life) Recovery (in %): Transformation products: not measured

 

The substance demonstrates a propensity towards degradation via abiotic routes.

 

Conclusion:

 

The substance is not considered to be persistent within the environment.