1,6-dichloro-1,6-dideoxy-β-D-fructofuranosyl 4-chloro-4-deoxy-α-D-galactose

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1983-09-20 to 1983-10-18

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

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

Version / remarks:

1981

Deviations:

yes

Remarks:

inoculum quantity like OECD modified MITI test (guideline 301C (1981))

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No. of test material: 153006
- Purity test date: 97.7%

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at ambient temperature

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Source of activated sludge: activated sludge from a laboratory porous pot plant
- Preparation of inoculum for exposure: A sample of activated sludge was allowed to settle. The supernatant was discarded and the remaining sludge mixed thoroughly. A 25 mL sample was taken for determination of the concentration of suspended solids in order to calculate the volume required for addition to the test medium to obtain a final concentration of 30 mg suspended solids/L.
- Concentration of sludge: 30 mg suspended solids/L

Duration of test (contact time):

28 d

Initial conc.:

4.5 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Composition of medium: mineral nutrients in distilled water
- Test temperature: 20 - 25°C
- Suspended solids concentration: 30 mg/L
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: flasks, necks of flasks loosely covered with foil
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: flasks were placed on a shaker

SAMPLING
- Sampling frequency: On day 0, 7, 14, 22 and 28
- Sampling method: Samples (50 mL) of each solution were taken and filtered through polycarbonate membranes of 0.2 µm pore size. The first 20 mL of filtrate was discarded and the remaining 30 mL was collected for duplicate determinations of DOC using a Carlo Erba total carbon monitor (400/P).

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Other: reference with sodium benzoate

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (DOC removal)

Value:

4

Sampling time:

28 d

Results with reference substance:

mean percentage removal of reference substance after 7 days = 92%

sample	flask	Day 0		Day 7			Day 14			Day 22			Day 28
		DOC [mg/L]	DOC corrected [mg/L]	DOC [mg/L]	DOC corrected [mg/L]	removal [%]	DOC [mg/L]	DOC corrected [mg/L]	removal [%]	DOC [mg/L]	DOC corrected [mg/L]	removal [%]	DOC [mg/L]	DOC corrected [mg/L]	removal [%]
blank	mean	1.8	-	2.7	-	-	3.15	-	-	4.95	-	-	1.55	-	-
reference	3	21.0	19.2	4.6	1.9	90	3.8	0.5	97	5.1	0.2	99	1.7	0.2	99
	4	21.6	19.8	3.6	0.9	95	3.5	0.4	98	4.5	0.0	100	1.6	0.1	99
test	5	12.5	10.7	14.2	11.5	0	12.3	9.2	14	22.9	18.0*	0	11.8	10.3	3
	6	12.8	11.0	15.7	13.0	0	12.9	9.8	11	21.0	16.1*	0	12.0	10.5	5

* The unusually high values may be a result of an instrument error.

Validity criteria fulfilled:

not specified

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The biodegradation of the test substance was determined in a GLP study according to OECD 301 E. Within the test period of 28 days, a degradation of 4% was determined for the test substance. The test item was not significantly biodegraded under the conditions of this test.

Description of key information

Based on the study results, the test substance can be considered for classification as not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

The biodegradation of test item was determined in a GLP study according to OECD 301 E. The method is based on the removal of the dissolved organic carbon (DOC) of the test substance from a mineral medium inoculated with 30 mg activated sludge per L from a plant treating predominantly domestic sewage.Within the test period of 28 days, a degradation of 4% was determined for the test substance. A toxicity control was not included in the test. 

Based on the study results and according to the criteria given in the ECHA Guidance (Guidance on the Application of the CLP Criteria) from 2015, the test substance can be considered for classification as not readily biodegradable.