Isooctyldinitrophenol

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21st August 1985 - 25th September 1985

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Work was carried out under supervision according to the procedures herein described and according to the OECD principles of Good Laboratory Practice.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1985

Report date:

1985

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Isooctyldinitrophenol

EC Number:

253-410-9

EC Name:

Isooctyldinitrophenol

Cas Number:

37224-61-6

Molecular formula:

C14H20N2O5

IUPAC Name:

4-(6-methylheptyl)-3,5-dinitrophenol

Test material form:

liquid: viscous

Details on test material:

The test substance was received from Thomas Swan & Co. Ltd., Crookhall, Consett, Durham, DH8 7ND, on the 30 May 1985. Substance was a brown, viscous liquid contained in a white opaque plastic bottle with a screw cap.

Sample No DNCP B 68/85 Thomas Swan and Co. Ltd, Consett, Co Durham.

The inclusive weight of the test substance and container on recipt was 482.03g. The test substance was stored under ambient temperature until required.

Chemical name: Dinitro capryl phenol (DNCP) batch number P511.
Other names: Dinitro octyl phenol
Formula: C14H20N2O5
Chemical composition: DNCP 89.9%, MNOP 4.6%, NDOP 4.0%, TNP 1.0%
Appearance, colour: Dark red
Solubility in water: 30mg/l
Specific gravity: 1.1.3
pH: 1.8 - 2.0
Stability: Stable, instability caused by overheating
Intended use: fungicide

Analysis Report:
DNCP P511 B^8.85
- 0.08% H2O
- 89.9% DNCP
- 4.55% MNCP
- 0.53% strong as as Picric Acid
- 3.24 meq/grm Total titratable phenols

Reference substance: sodium Benzoate, the reference substance used in this test, was supplied by BDH Chemicals, product number 30112/573315085009, and a purity of 99%.

Study design

Inoculum or test system:

sewage, domestic (adaptation not specified)

Details on inoculum:

Sewage inoculum:

The inoculum was effluent from a treatment plant dealing with a predominantly domestic sewage.

A sample of secondary effluent was collected within 24 hours of the start of the test. The sample was continuously aerated up to 1 hour before it was required, when the aeration was stopped and the effluent allowed to settle. The supernatant from this was used as th inoculum in the test.

Duration of test (contact time):

> 0 - < 28 d

Details on study design:

The pH values remained at pH 7.5 to 7.6 until Day 28, when there was a decrease in pH between 6 and 7 in the mixtures in all the flasks except flask 2.The pH in flask 2 on Day 28 was 7.5.

Results and discussion

% Degradation

% Degradation 1

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

7 d

% Degradation 2

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

14 d

% Degradation 3

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

21 d

% Degradation 4

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

28 d

Details on results:

The above shows percentage removal of DOC from each test mixture, calculated from the blank calculated from the blank corrected data as given in Table 4.

There was no trend to indicate significant removal of the test substance during the 28 day test.

The percentage removal of DOC from the mixture containing soidum benzoate had reach >90% by Day 7 and remained at this level until the end of the test (Table 5).

Any other information on results incl. tables

RESULTS

The mean DOC concentrations of the nominal 10, 15 and 17mg/l solutions of the test substance in deionised water were all <1mg/l (Table 1). This shows low solubility of the test substance in unbuffered deionised water.

Table 1: Mean DOC concentration of nominal 10, 15 and 17 mg/l solutions of the test substance in deionised water.

Nominal concentration of DNCP (mg/l)	Mean DOC Concentration (mgC/l)
10	0.7
15	0.8
17	0.8

Solutions were nominally 5, 10, 15 and 17mg/l were then prepared in deionised water containing phosphate buffer at concentrations to be used in the test mixtures. The DOC concentrations of these mixtures increased with increasing nominal concentration up to a nominal concentration of 15mg/l (Table 2). This indicated that the limit of solubility of the test substance in the buffered mineral salts medium was likely to be <15mg/l. therefore, it was decided to prepare a mixture containing the test substance at a nominal concentration of 10mg/l (expected DOC concentration 4 to 5 mg C/l) in buffered mineral salts medium, at the start of the test.

Table 2: DOC concentrations of nominal 5, 10, 15 and 17 mg/l solutions of the test substance in buffered deionised water.

Nominal concentration of DNCP (mg/l)	DOC concentration (mg C/l)
5	3.0
10	4.6
15	6.0
17	5.1

The mixture containing the test substance in mineral salts medium had a mean DOC concentration of 4.2 mg C/l (Table 3) at the start of the test and the mixture was yellow in colour. There was no evidence to suggest that the DOC concentration in this mixture decreased during the 28 day test and no change in the colour of the mixture was observed.

Table 3: DOC concentrations during the test (mg C/l)

			Sampling times (Days)
			0	7	14	21	28
DNCP		rep 1	4.3	-	-	-	-
		rep 2	4.1	-	-	-	-
		mean	4.2	-	-	-	-
	Flask 1	rep 1	-	3.9	4.4	3.8	3.2
		rep 2	-	4.1	4.4	4.0	3.6
		mean	-	4.0	4.4	3.9	3.4
	Flask 2	rep 1	-	4.0	4.2	4.3	4.5
		rep 2	-	4.2	4.2	4.2	4.6
		mean	-	4.1	4.2	4.2	4.5
Sodium Benzoate	Mixture	rep 1	21.2	-	-	-	-
		rep 2	21.8	-	-	-	-
		mean	21.5	-	-	-	-
	Flask 3	rep 1	-	1.7	2.0	1.3	1.6
		rep 2	-	1.2	1.8	1.2	1.4
		mean	-	1.5	1.9	1.2	1.5
	Flask 4	rep 1	-	1.9	2.1	1.3	1.8
		rep 2	-	1.1	1.8	1.4	1.5
		mean	-	1.5	1.9	1.3	1.6
DOC Blank	Mixture	rep 1	0.8	-	-	-	-
		rep 2	0.4	-	-	-	-
		mean	0.6	-	-	-	-
	Flask 5	rep 1	-	<0.2	0.9	0.2	0.6
		rep 2	-	<0.2	0.9	1.2	0.5
		mean	-	<0.2	0.9	0.7	0.6
	Flask 6	rep 1	-	<0.2	<0.2	<0.2	0.5
		rep 2	-	<0.2	<0.2	<0.2	0.5
		mean	-	<0.2	<0.2	<0.2	0.5

The mean DOC concentration of the mixture containing sodium benzoate started at approximately 21 mg C/l but had decreased to < 2mg/l by Day 7. The mean DOC concentration in this mixture remained <2 mg/l between Day 7 and Day 28.

The DOC concentration of the blank mixture remained < 1mg C/l throughout the test.

Table 4: Mean DOC concentrations of the test mixtures after blank correction.

	Sampling time (days)
	0	7	14	21	28
DNCP	3.6	3.9	3.8	3.7	3.4
Sodium Benzoate	20.9	1.3	1.4	0.9	1.0

Table 5: Percentage removal of DOC

	Sampling time (days)
	7	14	21	28
Sodium Benzoate	94	93	96	95

Applicant's summary and conclusion

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The results of this test indicate that DNCP is not readily biodegradable.