5-ethylpyridine-2-ethanol

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP - guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.4-E (Determination of the "Ready" Biodegradability - Closed Bottle Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

5-ethylpyridine-2-ethanol

EC Number:

226-024-3

EC Name:

5-ethylpyridine-2-ethanol

Cas Number:

5223-06-3

Molecular formula:

C9H13NO

IUPAC Name:

2-(5-ethylpyridin-2-yl)ethan-1-ol

Test material form:

other: viscous liquid

Details on test material:

- Name of test material (as cited in study report) : 5-Ethyl-2-(2-hydroxyethyl)-pyridin
- Physical state : clear , viscous liquid
- Analytical purity : 96,5%
- Lot/batch No. : 07040163/102
- Expiration date of the lot/batch : 2005-12-15
- Storage condition of test material : room temperature , closed original container , protected from light

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure) : Effluent of the treatment plant "Gemeinschaftsklärwerk Bitterfeld-Wolfen" , receiving predominantly domestic sewage
- Pretreatment : A fresh sample was allowed to settle for 1 hour and the decanted liquid was used for the test in a concentration of 0,6 ml/l .

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

2.5 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

other: oxygen evolution

Details on study design:

TEST CONDITIONS
- Composition of medium : The test item was dispersed in mineral medium in a concentration of 2,5 mg/l , the inoculum was added and the mixture was filled into the BOD bottles , so that the bottles were completely filled .
- Test temperature : 20,0°C
- pH adjusted : no
- Continuous darkness : yes

TEST SYSTEM
- Culturing apparatus : BOD bottles , stoppered
- Number of culture flasks/concentration : 2
- Measuring equipment : dissolved oxygen was analysed by the electrode method


SAMPLING
- Sampling frequency : after 0, 2, 5, 9, 13, 16, 19, 23, 26 and 28 days

CONTROL AND BLANK SYSTEM
- Inoculum blank : yes
- Abiotic sterile control : -
- Toxicity control : yes

Reference substance

Reference substance:

benzoic acid, sodium salt

Remarks:

(3,3 mg/l)

Results and discussion

% Degradation

Parameter:

other: oxygen evolution

Value:

> 0 - <= 9

Sampling time:

28 d

Details on results:

For the test item , no marked reduction of the oxygen concentration was observed . Throughout the experiment small values of oxygen uptake were measured . As the results range from 0 to 9 % and do not exceed 9 % at any time they can not be interpreted as a degradation of the test item .

BOD5 / COD results

Results with reference substance:

On day 2 the reference substance reached the pass level for ready biodegradability (60%) . The result is the criteria for normal testing .

Any other information on results incl. tables

Results of dissolved oxygen analysis

Day	Concentration of dissolved oxygen (mgO2/l)
	Inoculum control	Procedure control	Test item	Toxicity control
0	9,0	9,0	9,0	9,0
	9,0	9,0	9,0	9,0
2	8,8	5,3	8,7	5,4
	8,7	5,1	8,6	5,2
5	8,5	4,3	8,4	4,2
	8,6	4,2	8,5	4,1
9	8,6	4,0	8,3	3,7
	8,5	4,0	8,5	3,7
13	8,4	3,9	8,1	3,4
	8,4	3,9	8,2	3,5
16	7,8	-	8,0	-
	7,8	-	7,8	-
19	7,5	-	7,6	-
	7,5	-	7,5	-
23	7,6	-	7,1	-
	7,6	-	7,0	-
26	7,4	-	7,3	-
	7,5	-	7,2	-
28	7,7	-	7,3	-
	7,4	-	7,6	-

Calculated oxygen depletion

Day	Oxygen depletion (mgO2/l)
	Procedure control		Test item		Toxicity control
	Bottle 1 and 2	Mean	Bottle 1 and 2	Mean	Bottle 1 and 2	Mean
2	3,45	3,55	0,05	0,10	3,35	3,45
	3,65		0,15		3,55
5	4,25	4,30	0,15	0,10	4,35	4,40
	4,35		0,05		4,45
9	4,55	4,55	0,25	0,15	4,85	4,85
	4,55		0,05		4,85
13	4,50	4,50	0,30	0,25	5,00	4,95
	4,50		0,20		4,90
16	-	-	-0,20	-0,10	-	-
	-		0		-
19	-	-	-0,10	-0,05	-	-
	-		0		-
23	-	-	0,50	0,55	-	-
	-		0,60		-
26	-	-	0,15	0,20	-	-
	-		0,25		-
28	-	-	0,25	0,10	-	-
	-		-0,05		-

Degradation of the test item and reference substance

Day	Degradation (%)
	Procedure control	Test item
2	64	2
5	78	2
9	83	3
13	82	4
16	-	0
19	-	0
23	-	9
26	-	3
28	-	2

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

The percentage degradation of the reference compound has reached the pass level of 60% on day 2; The residual concentration of oxygen did not fall below 0.5 mg/l

Interpretation of results:

other: not readiliy biodegradable

Conclusions:

The test substance was tested for the ready biological degradability in Closed Bottle Test. The test was performed according to EEC Directive 92/69/EEC, Annex V, Determination of the Ready Biodegradability, C.4E Closed Bottle Test without deviations and therefore considered to be of the highest quality (reliability Klimisch 1). The validity criteria of the test system are fulfilled. In the present study no marked oxygen uptake by the test item was measured . The pass level for ready biodegradation (60% degradation) was not reached . For this reason in the test for ready biodegradability the test item seems to be not ready biodegradable .

Executive summary:

The biodegradability of the substance 5-Ethyl-2-(2-hydroxyethyl)-pyridin was investigated according to EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test). The study was conducted in compliance with the Principles of Good Laboratory Practice (GLP). Mineral medium containing a known concentration of the test item was inoculated with micro organisms from the effluent of a treatment plant (predominantly domestic sewage) and incubated in the dark over a 28 day period. Degradation was followed by oxygen evolution twice a week. The amount of oxygen taken up by the microbial population during biodegradation of the test item is expressed as a percentage of the theoretical oxygen demand of the test item. For the test item, no marked reduction of the O2 concentration was observed. Throughout the experiment small values of O2 uptake were measured. As the results range from 0 to 9 % and do not exceed 9 % at any time they can not be interpreted as a degradation of the test item.. The result of a toxicity control showed that the concentration of test item tested had no inhibitory effect to the inoculum. The pass level for ready biodegradation (60 % degradation) was not reached. Thus in the test for ready biodegradability the test item seems to be not readily biodegradable.