2-ethylhexyl (4-chloro-2-methylphenoxy)acetate

Biodegradation in soil

Administrative data

Endpoint:

biodegradation in soil, other

Remarks:

Aerobic and unaerobic transformation in soil

Type of information:

experimental study

Adequacy of study:

key study

Study period:

07.06.2005 - 25.06.2005

Reliability:

1 (reliable without restriction)

Cross-reference

Reason / purpose for cross-reference:

read-across source

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 307 (Aerobic and Anaerobic Transformation in Soil)

GLP compliance:

yes (incl. QA statement)

Test type:

laboratory

Test material

Test material information

Constituent 1

Reference substance name:

(4-chloro-2-methylphenoxy)acetic acid

EC Number:

202-360-6

EC Name:

(4-chloro-2-methylphenoxy)acetic acid

Cas Number:

94-74-6

Molecular formula:

C9H9ClO3

IUPAC Name:

(4-chloro-2-methylphenoxy)acetic acid

impurity 1

Reference substance name:

Water

EC Number:

231-791-2

EC Name:

Water

Cas Number:

7732-18-5

Molecular formula:

H2O

IUPAC Name:

water

impurity 2

Reference substance name:

4-chloro-o-cresol

EC Number:

216-381-3

EC Name:

4-chloro-o-cresol

Cas Number:

1570-64-5

Molecular formula:

C7H7ClO

IUPAC Name:

4-chloro-2-methylphenol

Test material form:

solid

Radiolabelling:

no

Study design

Soil properties

Soil properties 1

Soil no.:

#1

Soil type:

loamy sand

% Clay:

16

% Silt:

19

% Sand:

65

% Org. C:

6.1

pH:

6.8

CEC:

22.2 other: cmol/kg

Bulk density (g/cm³):

1.02

Soil properties 2

Soil no.:

#2

Soil type:

silt loam

% Clay:

6

% Silt:

76

% Sand:

18

% Org. C:

1.7

pH:

6.1

CEC:

8 other: cmol/kg

Bulk density (g/cm³):

1.18

Soil properties 3

Soil no.:

#3

Soil type:

loamy sand

% Clay:

10

% Silt:

21

% Sand:

69

% Org. C:

1.4

pH:

5.7

CEC:

3.3 other: cmol/kg

Bulk density (g/cm³):

1.46

Soil properties 4

Soil no.:

#4

Soil type:

Silt

% Clay:

21

% Silt:

76

% Sand:

3

% Org. C:

1.4

pH:

7

CEC:

11.5 other: cmol/kg

Bulk density (g/cm³):

1.18

Results and discussion

Half-life / dissipation time of parent compound

Half-life / dissipation time of parent compound 1

Key result

Soil No.:

#1

DT50:

3.7 d

Type:

(pseudo-)first order (= half-life)

Temp.:

>= 18 - <= 22 °C

Remarks on result:

other:

Remarks:

soil #1

Half-life / dissipation time of parent compound 2

Key result

Soil No.:

#2

DT50:

6.5 d

Type:

(pseudo-)first order (= half-life)

Temp.:

>= 18 - <= 22 °C

Remarks on result:

other:

Remarks:

soil #2

Half-life / dissipation time of parent compound 3

Key result

Soil No.:

#3

DT50:

7.1 d

Type:

(pseudo-)first order (= half-life)

Temp.:

>= 18 - <= 22 °C

Remarks on result:

other:

Remarks:

soil #3

Half-life / dissipation time of parent compound 4

Key result

Soil No.:

#4

DT50:

5.4 d

Type:

(pseudo-)first order (= half-life)

Temp.:

>= 18 - <= 22 °C

Remarks on result:

other:

Remarks:

soil #4

Transformation products:

yes

Identity of transformation products

Reference

Reference substance name:

Unnamed

IUPAC name:

4-chloro-2-methylphenol

Inventory number:

InventoryMultipleMappingImpl [inventoryEntryValue=EC 216-381-3]

CAS number:

1570-64-5

Identity:

4-chloro-o-cresol

Identity:

Phenol, 4-chloro-2-methyl-

Molecular formula:

C7H7ClO

Molecular weight:

142.583

SMILES notation:

Cc1cc(Cl)ccc1O

InChl:

InChI=1/C7H7ClO/c1-5-4-6(8)2-3-7(5)9/h2-4,9H,1H3

Any other information on results incl. tables

The concentrations of MCPA in the soil samples obtained during the experiment are presented in Tables

Table 1. MCPA TECHNICAL - aerobic transformation in soil concentration of MCPA in soil I during the experiment

Day /date	Concentration in soil mg/kg d.w.	concentration in soil mg/kg d.w	SD	RSD [%]	Percent of the initial concentration [%]	Decrease in relation to the initial concentration [%]
0	13.55
24.05.2005		14.03	0.55	4.9	100.0	0.0
	14.53
1	10.77
25.05.2005		11.11	0.38	4.30	79.1	20.9
	11.45
3	7.16
27.05.2005		7.07	0.10	1.74	50.3	49.7
	6.98
6	2.38
30.06.2005		2.39	0.02	0.86	17.0	83.0
	2.41
9	<0.1
2.06.2005		<0.1	-	-	-	-
	<0.1
12	<0.1
5.06.2005		<0.1	-	-	-	-
	<0.1
16	<0.1
9.06.2005		<0.1	-	-	-	-
	<0.1
20	<0.1
13.06.2005		<0.1	-	-	-	-
	<0.1
32	<0.1
25.06.2005		<0.1	-	-	-	-
	<0.1

 

 

Table 2. MCPA TECHNICAL - aerobic transformation in soil concentration of MCPA in soil II during the experiment

Day /date	Concentration in soil mg/kg d.w.	concentration in soil mg/kg d.w	SD	RSD [%]	Percent of the initial concentration [%]	Decrease in relation to the initial concentration [%]
0	12.43
24.05.2005		12.12	0.36	3.70	100.0	0.0
	11.80
1	10.58
25.05.2005		10.73	0.17	1.96	88.5	11.5
	10.88
3	8.12
27.05.2005		8.43	0.34	5.11	69.5	30.5
	8.73
6	4.41
30.06.2005		4.40	0.01	0.28	36.3	63.7
	4.40
9	2.13
2.06.2005		2.21	0.09	5.24	18.2	81.8
	2.29
12	1.02
5.06.2005		1.11	0.10	11.43	9.1	90.9
	1.20
16	0.12
9.06.2005		0.12	0.01	8.92	0.9	99.1
	0.11
20	<0.1
13.06.2005		<0.1	-	-	-	-
	<0.1
32	<0.1
25.06.2005		<0.1	-	-	-	-
	<0.1

 

Table 3. MCPA TECHNICAL - aerobic transformation in soil concentration of MCPA in soil III during the experiment

Day /date	Concentration in soil mg/kg d.w.	concentration in soil mg/kg d.w	SD	RSD [%]	Percent of the initial concentration [%]	Decrease in relation to the initial concentration [%]
0	12.81
24.05.2005		13.10	0.32	3.09	100.0	0.0
	13.39
1	9.98
25.05.2005		10.03	0.06	0.70	76.5	23.5
	10.08
3	7.22
27.05.2005		7.09	0.14	2.41	54.1	419
	6.97
6	4.94
30.06.2005		4.95	0.01	0.36	37.7	62.3
	4.96
9	4.25
2.06.2005		4.19	0.07	1.99	31.9	68.1
	4.13
12	3.42
5.06.2005		3.32	0.11	4.19	25.3	74.7
	3.22
16	2.43
9.06.2005		2.42	0.01	0.42	18.4	81.6
	2.41
20	1.67
13.06.2005		1.50	0.20	16.32	11.4	88.6
	1.33
32	0.15
25.06.2005		0.15	0.00	0.89	1.1	98.9
	0.14

 

Table 4. MCPA TECHNICAL - aerobic transformation in soil concentration of MCPA in soil IV during the experiment

Day /date	Concentration in soil mg/kg d.w.	concentration in soil mg/kg d.w	SD	RSD [%]	Percent of the initial concentration [%]	Decrease in relation to the initial concentration [%]
0	15.51
24.05.2005		15.23	0.32	2.62	100.0	0.0
	14.95
1	12.92
25.05.2005		12.76	0.19	1.84	83.7	16.3
	12.59
3	9.97
27.05.2005		9.98	0.01	0.15	65.5	34.5
	9.99
6	3.85
30.06.2005		4.02	0.19	6.05	26.3	73.7
	4.19
9	1.76
2.06.2005		1.93	0.20	1.28	12.6	87.4
	2.11
12	0.24
5.06.2005		0.18	0.07	4.77	1.1	98.9
	0.12
16	<0.1
9.06.2005		<0.1	-	-	-	-
	<0.1
20	<0.1
13.06.2005		<0.1	-	-	-	-
	<0.1
32	<0.1
25.06.2005		<0.1	-	-	-	-
	<0.1

 

 

The concentrations of 4-chloro-2-metylophenol in the soil samples obtained during the experiment are presented in Tables

Table 5. aerobic transformation in soil concentration of 4-chloro-2-metylophenol in soil I during the experiment

Day /date	Concentration in soil mg/kg d.w.	Mean concentration in soil mg/kg d.w.	SD	RSD [%]
0	<0.05
24.05.2005		<0.05	-	-
	<0.05
^1	<0.05
25.05.2005		<0.05	-	-
	<0.05
3	<0.05
27.05.2005		<0.05	-	-
	<0.05
6	0.12
30.06.2005		0.11	0.00	0.00
	0.11
9	<0.05
2.06.2005		<0.05	-	-
	<0.05
12	0.25
5.06.2005		0.28	0.04	0.01
	0.31
16	<0.05
9.06.2005		<0.05	-	-
	<0.05
20	<0.05		-	-
13.06.2005		<0.05
	<0.05
32	<0.05
25.06.2005		<0.05	-	-
	<0.05

 

 

Table 6. aerobic transformation in soil concentration of 4-chloro-2-metylophenol in soil II during the experiment

 

Day /date	Concentration in soil mg/kg d.w.	Mean concentration in soil mg/kg d.w.	SD	RSD [%]
0	<0.05
24.05.2005		<0.05	-	-
	<0.05
^1	<0.05
25.05.2005		<0.05	-	-
	<0.05
3	<0.05
27.05.2005		<0.05	-	-
	<0.05
6	0.09
30.06.2005		0.09	0.00	0.00
	0,09
9	<0.05
2.06.2005		<0.05	-	-
	<0.05
12	<0.05
5.06.2005		<0.05	-	-
	<0.05
16	<0.05
9.06.2005		<0.05	-	-
	<0.05
20	<0.05
13.06.2005		<0.05	-	-
	<0.05
32	<0.05
25.06.2005		<0.05	-	-
	<0.05

 

Table 7. aerobic transformation in soil concentration of 4-chloro-2-metylophenol in soil III during the experiment

Day /date	Concentration in soil mg/kg d.w.	Mean concentration in soil mg/kg d.w.	SD	RSD rxI
0	<0.05
24.05.2005		<0.05	-	-
	<0.05
1	<0.05
25.05.2005		<0.05	-	-
	<0.05
3	<0.05
27.05.2005		<0.05	-	-
	<0.05
6	<0.05
30.06.2005		<0.05	-	-
	<0.05
9	<0.05
2.06.2005		<0.05	-	-
	<0.05
12	<0.05
5.06.2005		<0.05	-	-
	<0.05
16	0.13
9.06.2005		0.15	0.02	15.42
	0.16
20	0.19
13.06.2005		0.18	0.01	5.27
	0.17
32	0.16
25.06.2005		0.17	0.02	13.71
	0.09

 

Table 8. aerobic transformation in soil concentration of 4-chloro-2-metylophenol in soil IV during the experiment

 

Day /date	Concentration in soil mg/kg d.w.	Mean concentration in soil mg/kg d.w.	SD	RSD rxI
0	<0.05
24.05.2005		<0.05	-	-
	<0.05
1	<0.05
25.05.2005		<0.05	-	-
	<0.05
3	0.09
27.05.2005		0.09	0.00	0.00
	0.09
6	0.09
30.06.2005		0.08	0.01	12.5
	0.08
9	0.09
2.06.2005		0.09	0.00	0.00
	0.09
12	<0.05
5.06.2005		<0.05	-	-
	<0.05
16	<0.05
9.06.2005		<0.05	-	-
	<0.05
20	<0.05
13.06.2005		<0.05	-	-
	<0.05
32	<0.05
25.06.2005		<0.05	-	-
	<0.05

 

Taking into account the obtained results it was assessed that MCPA TECHNICALwas degraded, and the DT₅₀is 3.7, 6.5, 7.1 and 5.4 days for loamy sand (soil I), silt loam (soil II), loamy sand (soil III) and silt (soil IV), respectively.

 

 

Applicant's summary and conclusion

Conclusions:

Taking into account the obtained results it was assessed that degradation of MCPA TECHNICAL in aerobic conditions depended on the parameters of soils, used in the experiment. However, DT50 values for MCPA in tested soils did not exceeded 8 days.