Reaction mass of 2-hydroxyisopropyl 2-hydroxypropyl bicarbamate and 2-hydroxypropyl carbazate and propylene carbonate

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:

23 May - 20 Jun 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Deviations:

yes

Remarks:

Due to a malfunction of the cooling system on day 27 temperatures rose to a maximum of 45 °C on the last day of the test. This increase did not influence the overall test result.

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of 2-hydroxyisopropyl 2-hydroxypropyl bicarbamate and 2-hydroxypropyl carbazate and propylene carbonate

EC Number:

906-521-8

Cas Number:

85391-60-2

Molecular formula:

C8H16N2O6

IUPAC Name:

Reaction mass of 2-hydroxyisopropyl 2-hydroxypropyl bicarbamate and 2-hydroxypropyl carbazate and propylene carbonate

Test material form:

liquid

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Activated sludge from the aeration tank of the sewage treatment plant Odenthal, Germany (date of collection: 21 May 2002)
- Pretreatment: none
- Concentration of sludge: 30 mg/L ss

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: according to guideline
- Test temperature: 20 ± 1 °C
- pH: 7.5 (end of incubation); In one replicate the pH dropped to 5.9 due to malfunction of cooling apparatus
- pH adjusted: no
- Other: 25 mg test substance was weighed out on aluminium foil. This substance incl. aluminium foil was added to the test vessels.

TEST SYSTEM
- Culturing apparatus: Voith Sapromat (250 mL; continuously stirred)
- Number of culture flasks/concentration: 3
- Measuring equipment: BOD was continuously measured; NO2-N/NO2-N was analysed and the sum of both was determined by flow analysis (CFA and FIA) and spectrometric detection (EN ISO 13395)
- Test performed in closed vessels: yes

SAMPLING
- Sampling frequency: continuous analysis of BOD

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes, 3 bottles
- Abiotic sterile control: no
- Toxicity control: yes, 2 bottles
- Other: reference substance: yes, 3 bottles

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

28

Sampling time:

28 d

Remarks on result:

other: Mean of three replicates

BOD5 / COD results

Results with reference substance:

The reference substance was degraded to 85% after 14 d and 90% after 28 d.

Any other information on results incl. tables

Table 1: Degradation of the test item, reference substance and toxicity control during study period

Replicate	Day	4	6	8	12	14	18	20	22	26	28
		Biodegradation of test item [%]
1		8	13	16	19	21	25	26	29	32	25
2		6	12	14	18	20	23	24	25	27	21
3		8	13	16	19	21	25	26	27	30	37
Mean		7	13	15	19	21	24	25	27	30	28
		Biodegradation of reference item [%]
1		61	71	77	82	84	88	89	89	91	89
2		62	72	79	85	88	91	92	94	95	94
3		62	71	77	82	84	87	88	89	91	86
Mean		62	71	78	83	85	89	90	91	92	90
		Biodegradation of toxicity control [%]
1		41	48	54	59	60	63	64	65	66	65
2		41	49	54	60	62	64	65	66	68	67
Mean		41	49	54	60	61	64	65	66	67	66

The BOD values on day 28 were corrected for the oxygen consumed by nitrification.

Table 2: Oxygen uptake by nitrification

	Time	NO3-N [mg/L]	Oxygen uptake [mg/L]	NO2-N [mg/L]	Oxygen uptake [mg/L]
Test substance	0 h	< 1.00	4.57	< 0.10	0.34
Test substance	28 d	1.37	6.26	< 0.10	0.34
Oxygen uptake	28 d	-	1.69	-	0.00

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable