Bis-O-(benzylidene)-D-glucitol

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July 21, 1994 to September 30, 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Version / remarks:

: Japanese MITI study

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure):
On site sludge sampling was carried out at 10 locations in Japan (including city sewage plants, industry sewage plants and rivers_.

- Pretreatment
Sludge sampling method:
City sewage - return sludge's from sewage plants were collected.
Rivers, lake and sea - Surface water and surface soil which was in contact with the atmosphere were collected.

Mixing of fresh and old activated sludge:
The filtrate (5 L) of the supernatant of the old activated sludge was mixed all together with each of the filtrate (500 mL) of the supernatant of a newly collected sludge (10 sources). The mixed filtrate (10 L) was aerated after the pH value of the mixture was adjusted to 7.0 ± 1.0.

- Method of cultivation:
Roughly 30 minutes after ceasing aeration of the sludge mixture, supernatant corresponding to about 1/3 of the whole volume was removed. Then the equal volume of dechlorinated water was added to the remaining portion. This mixture was aerated, and then a predetermined amount of synthetic sewage* was added to the mixture so that the concentration of the synthetic sewage was 0.1 % in the volume of dechlorinated water added. This procedure was repeated once every day. Cultivation was carried out at 25 ± 2°C.

* Synthetic sewage
Glucose, peptone and potassium dihydrogenphosphate were dissolved in dechlorinated water to obtain 5(W/V) % of the solution as to each components. The pH of the solution was adjusted to 7.0 ± 1. 0 with sodium hydroxide.

- Concentration of sludge:
30 mg/L (as the concentration of suspended solid).

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

other: Measurement of biochemical oxygen demand (BOD)

Parameter followed for biodegradation estimation:

test mat. analysis

Remarks:

Determination of test substance by HPLC

Details on study design:

Performance of biodegradation test:

Preparation for test:
(1) Measurement of concentration of suspended solid:
Concentration of suspended solid in the activated sludge was 4600 mg/l.

(2) Preparation of basal culture medium:
Each 3 mL of solutions A, B, C and D (see below), were made up to 1000 mL with purified water and then the pH of this solution was adjusted to 7.0.

(3) Reference substance: Aniline was used as a reference substance.

Preparation of test solutions:
The following six test solutions were prepared and cultivated.

(1) Addition of test substance or aniline.
(a) Test solution (water + test substance) (n=1, Vessel No. 3)
In one test vessel, 30 mg of the test substance was accurately weighed and added to 300 mL of purified water, so that the concentration reached 100 mg/l.

(b) Test solution (sludge + test substance) (n=3, Vessel No. 4, 5 and 6)
In each test vessel, 30 mg of the test substance was accurately weighed and added to 300 mL of the basal culture medium, so that the concentration reached 100 mg/l.

(c) Test solution (sludge + aniline) (n=1, Vessel No. 1)
In one test vessel, 29.5 µL (30.0 mg) of aniline was added into 300 mL of the basal culture medium, so that the concentration reached 100 mg/l.

(d) Test solution (control blank) (n=1, Vessel No. 2)
In one test vessel, nothing was added to 300 mL of the basal culture medium.

(2) Inoculation of activated sludge:
The activated sludge was added to each vessel (b), (c) and (d), so that the concentration of the suspended solid reached 30 mg/l.

Instruments and conditions of cultivation:
(1) Instruments for cultivation: Closed system oxygen consumption measuring apparatus
Vessel: 300 mL in volume
Absorbent for carbon dioxide: Soda lime No. 1
Stirring method: Each test solution was stirred by a magnetic stirrer.

(2) Conditions of cultivation:
Cultivation temperature: 25 ± 1°C
Cultivation duration: 28 days

Reference substance:

aniline

Test performance:

Percentage biodegradations of aniline calculated by the BOD values was 64% and 75% after 7 and 14 days.
It was concluded that the test conditions were valid. No adverse effects on the reliability of the test were noted.

Parameter:

other: BOD

Value:

0

Sampling time:

28 d

Parameter:

% degradation (test mat. analysis)

Remarks:

(HPLC)

Value:

2

Sampling time:

28 d

Details on results:

Points of degradation (test substance):
0 % degradation after 7 d
0 % degradation after 14 d
0 % degradation after 21 d
0 % degradation after 28 d

Results with reference substance:

Points of degradation (reference substance):
64 % degradation after 7 d
75 % degradation after 14 d
75 % degradation after 21 d
75 % degradation after 28 d

Appearances of test solutions

Appearances of test media in cultivation vessels were as follows:

	Test solution	Appearance
At the start of cultivation	Water + test substance	The test substance was not dissolved.
	Sludge + test substance	The test substance was not dissolved.
At the termination of cultivation	Water + test substance	The test substance was not dissolved.
	Sludge + test substance	The test substance was not dissolved. Growth of the sludge was not observed.

Percentage biodegradation:

Percentage biodegradation after 28 days were as follows:

	Percentage biodegradation (%)
	Vessel-4	Vessel-5	Vessel-6	Average
BOD	0	0	0	0
HPLC	5	0	0	2

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The test substance was not biodegraded by the micro-organisms under the test conditions.

Executive summary:

Biodegradation test of test substance by micro-organisms:

Conditions of cultivation:

(1) Concentration of test substance: 100 mg/L

(2) Concentration of activated sludge (as the concentration of suspended solid): 30 mg/L

(3) Volume of test solution: 300 mL

(4) Cultivation temperature: 25 ± 1°C

(5) Cultivation duration: 28 days

Measurement and analysis:

(1) Measurement of biochemical oxygen demand (BOD) with a closed system oxygen consumption measuring apparatus.

(2) Determination of test substance by high performance liquid chromatography (HPLC).

Results:

(1) Percentage biodegradation by BOD: 0%, 0%, 0%; average 0%

(2) Percentage biodegradation by HPLC: 5%, 0%, 0%; average 2%

Conclusion:

The test substance was not biodegraded by the micro-organisms under the test conditions.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Please see Section 13 for "Read-across justification to support the REACH registration of Bis-O-(benzylidene)-D-glucitol (EC 251-136-4) at 10-100 tpa" for full details.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
It is proposed that the structural similarity and properties of the target substance and the structural analogue (sources substance) are sufficiently close for there to be a reasonable expectation of similar effects.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Source substance:
IUPAC name: 1,3:2,4-bis-O-((3,4-dimethylphenyl)methylene) D-Glucitol
EC number: 413-110-2
CAS number: 135861-56-2


Target Substance: Bis-O-(benzylidene)-D-glucitol
IUPAC name: 1,3:2,4-bis-O-dibenzylidene-D-glucitol
EC number: 251-136-4
CAS number: 32647-67-9


3. ANALOGUE APPROACH JUSTIFICATION
Based on the structural similarity of the source substances and target substance, similarity of physic-chemical properties and similarity in experimental (eco)toxicological test data (and toxicokinetic behaviour assessment) it is concluded that target substance and the structural analogue (source substance) are sufficiently close for there to be a reasonable expectation of similar effects, for the endpoints where results have been read-across.

4. DATA MATRIX
Please see Section 13 for "Read-across justification to support the REACH registration of Bis-O-(benzylidene)-D-glucitol (EC 251-136-4) at 10-100 tpa" for full details.

Reason / purpose for cross-reference:

read-across source

Test performance:

Percentage biodegradations of aniline calculated by the BOD values was 64% and 75% after 7 and 14 days.
It was concluded that the test conditions were valid. No adverse effects on the reliability of the test were noted.

Parameter:

other: BOD

Value:

0

Sampling time:

28 d

Parameter:

% degradation (test mat. analysis)

Remarks:

HPLC

Value:

2

Sampling time:

28 d

Details on results:

Points of degradation (test substance):
0 % degradation after 7 d
0 % degradation after 14 d
0 % degradation after 21 d
0 % degradation after 28 d

Results with reference substance:

Points of degradation (reference substance):
64 % degradation after 7 d
75 % degradation after 14 d
75 % degradation after 21 d
75 % degradation after 28 d

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The test substance was not biodegraded by the micro-organisms under the test conditions.

Executive summary:

Biodegradation test of structural analogue source substance (EC 413-110-2) by micro-organisms:

Conditions of cultivation:

(1) Concentration of test substance: 100 mg/L

(2) Concentration of activated sludge (as the concentration of suspended solid): 30 mg/L

(3) Volume of test solution: 300 mL

(4) Cultivation temperature: 25± 1°C

(5) Cultivation duration: 28 days

Measurement and analysis:

(1) Measurement of biochemical oxygen demand (BOD) with a closed system oxygen consumption measuring apparatus.

(2) Determination of test substance by high performance liquid chromatography (HPLC).

Results:

(1) Percentage biodegradation by BOD: 0%, 0%, 0%; average 0%

(2) Percentage biodegradation by HPLC: 5%, 0%, 0%; average 2%

Conclusion:

The test substance (EC 413-110-2) was not biodegraded by the micro-organisms under the test conditions.

It is therefore considered that the target substance will not be readily biodegradable.

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

31 March 1988 and 28 April 1988

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.6 (Degradation: Chemical Oxygen Demand)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: HRC Limited sewage treatment plant - predominantly domestic sewage.
- Preparation of inoculum for exposure: The sample was allowed to settle and the supernatant filtered through Whatman GFA filter paper (first 250 mL discarded).

Duration of test (contact time):

28 d

Initial conc.:

2 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

other: Theoretical Oxygen demand (ThOD)

Details on study design:

TEST CONDITIONS
- Composition of medium: Activated sludge bacteria was obtained on 31 March 1988 from the aeration stage of the HRC Limited sewage treatment plant treating predominantly domestic sewage.
- Additional substrate: no
- Solubilising agent (type and concentration if used): chloroform (Fisons Distol Reagent Grade), to give a stock solution of 560 mg/10mL.
- Test temperature: 21 +/- 1°C
- pH adjusted: no
- Aeration of dilution water: no

TEST SYSTEM
- Culturing apparatus: 280 mL BOD bottles (darkend glass) with ground glass stoppers.
- Number of culture flasks/concentration: 2
- Measuring equipment: Yellow Springs BOD Probe (Model 57)
- Test performed in closed vessels due to significant volatility of test substance: no
- Test performed in open system: no
- Other: BOD bottles were filled, by siphon, and firmly stoppered to exclude all air bubbles. Sufficient bottles were prepared to allow a single oxygen determination per bottle to be made at 0, 5, 15 and 28 days for each test medium (duplicate bottles at each sampling time).
Bottles were incubated in a water bath at 21 +/- 1°C for 0, 5, 15 or 28 days as appropriate.


SAMPLING
- Sampling frequency: Sufficient bottles were prepared to allow a single oxygen determination per bottle to be made at 0, 5, 15 and 28 days for each test medium.
- Sampling method: Dissolved oxygen concentrations for each test medium were determined, in duplicate at 0, 5, 15 and 28 days by means of a Yellow Springs BOD Probe (Model 57).

CONTROL AND BLANK SYSTEM
Test concentrations:
- Non-inoculated dilution water.
- Inoculated dilution water.
- Inoculated dilution water plus filter paper.
- 3 mg/L sodium benzoate.

All but the first test media were inoculated with activated sludge filtrate at the rate of 1 drop of inoculum per litre.

Reference substance:

other: Sodium benzoate

Preliminary study:

Preliminary study not conducted.

Test performance:

Oxygen depletions in the inoculated and non-inoculated control series were within the prescribed limits:

Non-inoculated control : < 0.3 mgO2/L after 5 days
: < 0.4 mgO2/L after 28 days
Inoculated control : < 0.5 mgO2/L after 5 days
: < 0.6 mgO2/L after 28 days

Parameter:

other: Theoretical oxygen demand (ThOD)

Value:

> 2 - < 7

Sampling time:

28 d

Details on results:

Dissolved oxygen measurements for the test substance and standard substance solutions, together with the inoculated and non-inoculated blank controls, at 0, 5, 15 and 28 days are given in Table 1 (see attached). Mean oxygen depletion values and percentage degradation values (% of ThOD NO3) are given in Table 2 (see attached). For calculation of ThOD values see other information on results below.

Gell-All MD attained between 2 and 7% degradation within 28 days and cannot, therefore, be considered as readily biodegradable.

Results with reference substance:

Sodium benozoate attained 83% degradation within 28 days.

Theoretical Oxygen Demand (ThOD)

1. Sodium benzoate. C₆H₅COONa. Mol. wt. = 144

ThOD = 16 [14 + 2.5 + 0.5 - 2]/144 = 1.67 mg/O₂/L

Estimated oxygen depletion for 3 mg/L = 5.0 mgO₂/L

2. Gel-All MD. C₂₂H₂₆O₆. Mol. wt. = 386

ThOD = 16[44 + 13 - 6]/386 = 2.1 mgO₂/mg

Estimated oxygen depletion for 2 mg/L = 4.2 mgO₂/L

Validity criteria fulfilled:

yes

Interpretation of results:

other: Not readily biodegradable

Conclusions:

Gel-All MD attained between 2 and 7% degradation within 28 days and cannot, therefore, be considered as readily biodegradable.

Executive summary:

The Test Substance Gel-All MD was assessed for ready biodegradability over a 28 day period.

The test was conducted using the closed bottle test according to OECD Guideline N. 301D and EEC Directive 67/548 Annex V C6. as published in 84/449/EEC.

Results

Test concentration: 2 mg/L

Oxygen depletion (28 days): 0.100 mg O₂/L

Theoretical oxygen demand (ThOD): 4.2 mg O₂/L

Percentage biodegradation (28 days): 2 %

Gel-All MD attained between 2 and 7 % degradation within 28 days and cannot, therefore, be considered as readily biodegradable.

Sodium benzoate (reference substance) attained 83% degradation within 28 days. Oxygen depletions in the inoculated and non-inoculated control series were within prescribed limits.

Reference 4

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Please see Section 13 for "Read-across justification to support the REACH registration of Bis-O-(benzylidene)-D-glucitol (EC 251-136-4) at 10-100 tpa" for full details.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
It is proposed that the structural similarity and properties of the target substance and the structural analogue (sources substance) are sufficiently close for there to be a reasonable expectation of similar effects.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Soure substance:
IUPAC name: 1-(2,6-bis(4-tolyl)-1,3-dioxano(5,4-d)-1,3-dioxan-4-yl)ethane-1,2-diol
EC number: 402-950-5
CAS number: 87826-41-3

Target Substance: Bis-O-(benzylidene)-D-glucitol
IUPAC name: 1,3:2,4-bis-O-dibenzylidene-D-glucitol
EC number: 251-136-4
CAS number: 32647-67-9


3. ANALOGUE APPROACH JUSTIFICATION
Based on the structural similarity of the source substances and target substance, similarity of physic-chemical properties and similarity in experimental (eco)toxicological test data (and toxicokinetic behaviour assessment) it is concluded that target substance and the structural analogue (source substance) are sufficiently close for there to be a reasonable expectation of similar effects, for the endpoints where results have been read-across.

4. DATA MATRIX
Please see Section 13 for "Read-across justification to support the REACH registration of Bis-O-(benzylidene)-D-glucitol (EC 251-136-4) at 10-100 tpa" for full details.

Reason / purpose for cross-reference:

read-across source

Parameter:

other: Theoretical oxygen demand (ThOD)

Value:

> 2 - < 7

Sampling time:

28 d

Details on results:

Gell-All MD attained between 2 and 7% degradation within 28 days.

Results with reference substance:

Sodium benozoate attained 83% degradation within 28 days.

Validity criteria fulfilled:

yes

Interpretation of results:

other: Not readily biodegradable

Conclusions:

Gell-All MD attained between 2 and 7% degradation within 28 days and cannot, therefore, be considered as readily biodegradable.

Executive summary:

The Test Substance Gel-All MD (an analgoue source substance, EC 402 -950 -5) was assessed for ready biodegradability over a 28 day period.

The test was conducted using the closed bottle test according to OECD Guideline N. 301D and EEC Directive 67/548 Annex V C6. as published in 84/449/EEC.

Results

Test concentration: 2 mg/L

Oxygen depletion (28 days): 0.100 mg O₂/L

Theoretical oxygen demand (ThOD): 4.2 mg O₂/L

Percentage biodegradation (28 days): 2 %

Gel-All MD attained between 2 and 7% degradation within 28 days and cannot, therefore, be considered as readily biodegradable.

Sodium benzoate (reference substance) attained 83% degradation within 28 days. Oxygen depletions in the inoculated and non-inoculated control series were within prescribed limits.

It is therefore considered that the target substance will not be readily biodegradable.

Reference 5

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

Not applicable

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

results derived from a (Q)SAR model, with limited documentation / justification

Justification for type of information:

A QSAR predicition for biodegradation was made using EPI Suite model BIOWIN v4.10.

Qualifier:

no guideline followed

Principles of method if other than guideline:

A QSAR predicition for biodegradation was made using EPI Suite model BIOWIN v4.10.

GLP compliance:

no

Parameter:

other: Ready Biodegradability Prediction

Remarks on result:

other: Predicted not to be readily biodegradable

Validity criteria fulfilled:

not applicable

Interpretation of results:

not readily biodegradable

Conclusions:

BIOWIN v.410 predicts the substance to not be readily biodegradable.

Description of key information

The biodegradation in water of the substance (EC 251-136-4) has been assessed by reading across the results of ready biodegradation studies conducted on two structurally similar analogue substances, which are detailed below.

Source Substance; (EC-413 -110 -2):

Biodegradation test of substance (EC 413-110-2) by micro-organisms:

Conditions of cultivation:

(1) Concentration of test substance: 100 mg/L

(2) Concentration of activated sludge (as the concentration of suspended solid): 30 mg/L

(3) Volume of test solution: 300 mL

(4) Cultivation temperature: 25± 1°C

(5) Cultivation duration: 28 days

Measurement and analysis:

(1) Measurement of biochemical oxygen demand (BOD) with a closed system oxygen consumption measuring apparatus.

(2) Determination of test substance by high performance liquid chromatography (HPLC).

Results:

(1) Percentage biodegradation by BOD: 0%, 0%, 0%; average 0%

(2) Percentage biodegradation by HPLC: 5%, 0%, 0%; average 2%

Conclusion:

The test substance (EC 413-110-2) was not biodegraded by the micro-organisms under the test conditions.

Source Substance; Gel All MD (EC 402-950-5):

The Test Substance Gel-All MD (EC 402 -950 -5) was assessed for ready biodegradability over a 28 day period.

The test was conducted using the closed bottle test according to OECD Guideline N. 301D and EEC Directive 67/548 Annex V C6. as published in 84/449/EEC.

Results

Test concentration: 2 mg/L

Oxygen depletion (28 days): 0.100 mg O₂/L

Theoretical oxygen demand (ThOD): 4.2 mg O₂/L

Percentage biodegradation (28 days): 2 %

Gel-All MD attained between 2 and 7% degradation within 28 days and cannot, therefore, be considered as readily biodegradable.

Sodium benzoate (reference substance) attained 83% degradation within 28 days. Oxygen depletions in the inoculated and non-inoculated control series were within prescribed limits.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

Based on the results of ready biodegradation studies on two structurally similar substances, both of which were not readily biodegradable, it is considered that the target substance (EC 251-136-4) will not be readily biodegradable.

This is supported by a QSAR prediction, made using EPI Suite model BIOWIN v4.10, which predicts the target substance to not be readily biodegradable.