Fatty acids, C6-12, mixed tetraesters with heptanoic acid, pentaerythritol, 3,5,5-trimethylhexanoic acid and valeric acid

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:

22 January to 27 March 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study conducted in accordance with OECD and EU guidelines.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

Deviations:

no

GLP compliance:

yes

Remarks:

carbon analysis was subcontracted and not performed under GLP conditions.

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
See read-across justification attached to endpoint summary.

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

Source: The source of test organisms was activated sludge freshly obtained from a municipal sewage treatment plant: Waterschap de Maaskant', 's-Hertogenbosch, the Netherlands.

Treatment: The sludge was kept under continuous aeration until further treatment. The concentration of suspended solids was 3.9 g/1 in the concentrated sludge (information obtained from the municipal sewage treatment plant). Before use, the sludge was allowed to settle (30-90 minutes) and the liquid decanted for use as inoculum at the amount of 10 mL/L of mineral medium.

Duration of test (contact time):

28 d

Initial conc.:

17.5 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

PREPARATION OF TEST SOLUTIONS
The batch of HATCOL 3331 tested was a clear colourless liquid and hardly soluble in water. Based on the Total Carbon content (TC) of HATCOL 3331 (68.90%) the test substance was tested in duplicate at 35 mg per 2 litres, corresponding to 12 mg TC/1. Weighed amounts of HATCOL 3331 (test substance bottle A and B: 35.1 mg and toxicity control bottle: 35.5 mg) were mixed with 10 ml of milli-RO water. After vigorous shaking the resulting suspension was added quantitatively to the test medium containing the microbial organisms. The test solutions were continuously stirred during the test, to ensure optimal contact between the test substance and the test organisms.

REFERENCE SUBSTANCE CONCENTRATIONS
A solution of sodium acetate (Merck art. 1 062680250, batch TA 820068 033) was prepared by dissolving 799.8 mg in 200 ml Milli-RO water. Amounts of this stock solution corresponding to the 40 mg/1 sodium acetate (12 mg TOC/1) were added to the test medium of the positive control bottle and the toxicity control bottle.

TEST PROCEDURE AND CONDITIONS
Test duration: 28 days (last C02-measurement on the 29th day). During the test period aeration and stirring took place.
Test vessels: 2 litre all-glass brown coloured bottles.
Milli-RO I Milli-Q water: Tap-water purified by reverse osmosis (Milli-RO) and subsequently passed over activated carbon and ion exchange cartridges (Milli-Q) (Millipore Corp., Bedford, Mass., USA).
Stock solutions of mineral components:
A) 8.50 g KH2PO4, 21.75 g K2HPO4, 67.20 g Na2HP04.12H20, 0.50 g NH4CI dissolved in 1 I Milli-Q water, pH 7.4 ± 0.2
B) 22.50 g MgS04.7H20 dissolved in 1 I Milli-Q water.
C) 36.40 g CaCJ2.2H20 dissolved in 1 I Milli-Q water.
D) 0.25 g FeCI3.6H20 dissolved in 1 I Milli-Q water.
Mineral medium: 1 I mineral medium contains: 10 ml of solution (A), 1 ml of solutions (B) to (D) and Milli-RO water.
Barium hydroxide: 0.0125 M, stored in a sealed vessel to prevent absorption of C02 from the air.
CO2-free air: A mixture of oxygen (21 %) and nitrogen (79%) wasled through a bottle, containing 0.5- 1 litre 0.0125 M Ba(OHh solution to trap C02 which might be present in small amounts. The C02-free air was sparged through the scrubbing solutions at a rate of approximately 1-2 bubbles per second (ca. 30-100 ml/min).
Test concentration: The test substance was tested in duplicate at 35 mg per 2 litres, corresponding to 12 mg TC/1. The carbon
content was based on TC-analysis.

Preparation of bottles:
Pre-incubation medium: Mineral components, Milli-RO water (ca. 80% total volume) and inoculum (1% final volume) were added to each bottle. This mixture was aerated with C02-free air overnight to purge the system of CO2.
Type and number of bottles: Test suspension: containing test substance and inoculum (2 bottles). Inoculum blank: containing only inoculum (2 bottles). Positive control: containing reference substance and inoculum (1 bottle). Toxicity control: containing test substance, reference substance and inoculum (1 bottle).
Experimental C02 production: The C02 produced in each test bottle reacted with the barium hydroxide in the gas scrubbing bottle and precipitated out as barium carbonate. The amount of C02 produced was determined by titrating the remaining Ba(OHh with 0.05 M standardized HCI.
Measurements: Titrations were made every second or third day during the first 1 0 days, and thereafter at least every fifth day until the 28th day. Each time the C02-absorber nearest to the test bottle was removed for titration; each of the remaining two absorbers was moved one position in the direction of the test bottle. A new C02-absorber was placed at the far end of the series. Phenolphthalein was used as pH-indicator. On the 28th day, the pH of the test suspensions was measured and 1 ml of concentrated HCI was added to each bottle. The bottles were aerated overnight to drive off C02 present in the test suspension. The final titration was made on day 29.
Theoretical C02 production: Because the theoretical calculation of the C02 production was not possible and the test substance was insoluble in water, a sample of pure test substance was taken for determination of TC. TC analysis was performed at the Chemical Laboratory "Dr. A. Verwey", Rotterdam, the Netherlands using a Varia-analyzer. (Method: Varia El AV/29.007, 1999). TC analysis was not performed under GLP conditions.

Reference substance:

acetic acid, sodium salt

Preliminary study:

None

Test performance:

The positive control substance was degraded at least 60% within 14 days (74%).
The total C02 release in the blank at the end of the test did not exceed 40 mg/L (49 mg C02 per 2 litres of medium, this is 25 mg/L).
The difference of duplicate values for %-degradation of HATCOL 3331 was always less than 20.
Since all criteria for acceptability of the test were met, this study was considered to be valid.

Key result

Parameter:

% degradation (CO2 evolution)

Value:

22

Sampling time:

28 d

Remarks on result:

other: bottle A

Key result

Parameter:

% degradation (CO2 evolution)

Value:

18

Sampling time:

28 d

Remarks on result:

other: bottle B

Details on results:

The relative degradation values calculated from the measurements performed during the test period revealed 22 and 18% degradation of HATCOL 3331 for bottle A and B respectively.
Since biodegradation of HATCOL 3331 of at least 60% was not reached within 10 days after exceeding 1 0%, the criterion for ready biodegradability was not met. In the toxicity control more than 25% degradation occurred within 14 days (38%, based on ThC02). Therefore, the test substance was assumed to be not inhibitory on microbial activity.

Results with reference substance:

The positive control substance was degraded at least 60% within 14 days (74%).

Monitoring of temperature and pH

The temperature recorded in a vessel with water in the same room varied between 21.6 and 23.4 degrees C.

The pH values of the different test media were:

	Just before the start of the test:	On day 28:
Blank control (A)	7.5	7.3
Blank control (B)	7.5	7.3
Positive control	7.4	7.6
HATCOL 3331 (A)	7.4	7.3
HATCOL 3331 (B)	7.3	7.3
Toxicity control	7.4	7.6

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable, but failing 10-day window

Conclusions:

Read-across substance, HATCOL 3331, was not readily biodegradable under the conditions of the modified Sturm test.

Executive summary:

The study procedure was based on EEC directive 92/69, C.4-C, December 1992, and OECD guideline No. 301 B July 17, 1992.

The batch of read-across substance, HATCOL 3331, tested was a clear colourless liquid and hardly soluble in water. The Total Carbon content (TC) of HATCOL 3331 was determined to be 68.90%. Based on the TC content the Theoretical CO2 production (ThC02) of HATCOL 3331 was calculated to be 2.53 mg CO2/mg. HATCOL 3331 was tested for its ready biodegradability at 35 mg per 2 litres, corresponding to 12 mg TC/L.

The study consisted of six bottles:

2 blank controls (no test material),

2 test bottles (HATCOL 3331, 17.5 mg/L),

1 positive control (sodium acetate, 40 mg/L) and

1 toxicity control (HATCOL3331, 17.5 mg/L; plus sodium acetate, 40 mg/L).

Weighed amounts of HATCOL 3331 were mixed with 10 ml of milli-RO water and after vigorous shaking the resulting suspension was added quantitatively to the test medium containing the microbial organisms. The test solutions were continuously stirred during the test, to ensure optimal contact between the test substance and the test organisms.

The relative degradation values calculated from the measurements performed during the test period revealed 22 and 18% degradation of HATCOL 3331 for bottle A and B respectively. Since biodegradation of HATCOL 3331 of at least 60% was not reached within 10 days after exceeding 10%, the criterion for ready biodegradability was not met.

In the toxicity control HATCOL 3331 was found not to inhibit microbial activity. Since all acceptability criteria prescribed by the protocol were met, this study was considered to be valid.

In conclusion, HATCOL 3331 was not readily biodegradable under the conditions of the modified Sturm test presently performed.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 January to 27 March 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study conducted in accordance with OECD and EU guidelines.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

Deviations:

no

GLP compliance:

yes

Remarks:

carbon analysis was subcontracted and not performed under GLP conditions.

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
See read-across justification attached to endpoint summary.

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

Source: The source of test organisms was activated sludge freshly obtained from a municipal sewage treatment plant: Waterschap de Maaskant', 's-Hertogenbosch, the Netherlands.

Treatment: The sludge was kept under continuous aeration until further treatment. The concentration of suspended solids was 3.9 g/1 in the concentrated sludge (information obtained from the municipal sewage treatment plant). Before use, the sludge was allowed to settle (30-90 minutes) and the liquid decanted for use as inoculum at the amount of 10 mL/L of mineral medium.

Duration of test (contact time):

28 d

Initial conc.:

>= 17.5 - <= 18 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

PREPARATION OF TEST SOLUTIONS
The batch of HATCOL 5236 tested was a clear pale yellow liquid and was hardly soluble in water. Based on the Total Carbon content {TC) of HATCOL 5236 (65.97%} the test substance was tested in duplicate at 35-36 mg per 2 litres, corresponding to 12 mg TC/L. Weighed amounts of HATCOL 5236 (test substance bottle A: 35.8 mg; test substance bottle B: 35.0 mg and toxicity control bottle: 36.4 mg) were mixed with 10 ml of milli-RO water. After
vigorous shaking the resulting suspension was added quantitatively to the test medium containing the microbial organisms.
The test solutions were continuously stirred during the test, to ensure optimal contact between the test substance and the test organisms.

REFERENCE SUBSTANCE CONCENTRATIONS
A solution of sodium acetate (Merck art. 1062680250, batch TA 820068 033) was prepared by dissolving 799.8 mg in 200 ml Milli-RO water. Amounts of this stock solution corresponding to the 40 mg/L sodium acetate (12 mg TOC/L) were added to the test medium of the positive control
botlle and the toxicity control bottle.

TEST PROCEDURE AND CONDITIONS
Test duration: 28 days (last C02-measurement on the 29th day). During the test period aeration and stirring took place.
Test vessels: 2 litre all-glass brown coloured bottles.
Milli-RO I Milli-Q water: Tap-water purified by reverse osmosis (Milli-RO) and subsequently passed over activated carbon and ion exchange cartridges (Milli-Q) (Millipore Corp., Bedford, Mass., USA).
Stock solutions of mineral components:
A) 8.50 g KH2PO4, 21.75 g K2HPO4, 67.20 g Na2HP04.12H20, 0.50 g NH4CI dissolved in 1 I Milli-Q water, pH 7.4 ± 0.2
B) 22.50 g MgS04.7H20 dissolved in 1 I Milli-Q water.
C) 36.40 g CaCJ2.2H20 dissolved in 1 I Milli-Q water.
D) 0.25 g FeCI3.6H20 dissolved in 1 I Milli-Q water.
Mineral medium: 1 L mineral medium contains: 10 ml of solution (A), 1 ml of solutions (B) to (D) and Milli-RO water.
Barium hydroxide: 0.0125 M, stored in a sealed vessel to prevent absorption of C02 from the air.
CO2-free air: A mixture of oxygen (21 %) and nitrogen (79%) wasled through a bottle, containing 0.5- 1 litre 0.0125 M Ba(OH)2 solution to trap C02 which might be present in small amounts. The C02-free air was sparged through the scrubbing solutions at a rate of approximately 1-2 bubbles per second (ca. 30-100 ml/min).
Test concentration: The test substance was tested in duplicate at 35-36 mg per 2 litres, corresponding to 12 mg TC/L. The carbon content was based on TC-analysis.

Preparation of bottles:
Pre-incubation medium: Mineral components, Milli-RO water (ca. 80% total volume) and inoculum (1% final volume) were added to each bottle. This mixture was aerated with C02-free air overnight to purge the system of CO2.
Type and number of bottles: Test suspension: containing test substance and inoculum (2 bottles). Inoculum blank: containing only inoculum (2 bottles). Positive control: containing reference substance and inoculum (1 bottle). Toxicity control: containing test substance, reference substance and inoculum (1 bottle).
Preparation: The test substance and positive control were added to the bottles. The volumes of suspensions were made up to 2 litres with Milli-RO water, resulting in the mineral medium described before. Three C02-absorbers (bottles filled with 100 ml 0.0125 M Ba(OHM were connected in series to the exit air line of each test bottle.
Experimental C02 production: The C02 produced in each test bottle reacted with the barium hydroxide in the gas scrubbing bottle and precipitated out as barium carbonate. The amount of C02 produced was determined by titrating the remaining Ba(OH)2 with 0.05 M standardized HCI.
Measurements: Titrations were made every second or third day during the first 0 days, and thereafter at least every fifth day until the 28th day. Each time the C02-absorber nearest to the test bottle was removed for titration; each of the remaining two absorbers was moved one position in the direction of the test bottle. A new C02-absorber was placed at the far end of the series. Phenolphthalein was used as pH-indicator. On the 28th day, the pH of the test suspensions was measured and 1 ml of concentrated HCI was added to each bottle. The bottles were aerated overnight to drive off C02 present in the test suspension. The final titration was made on day 29.
Theoretical C02 production: Because the theoretical calculation of the C02 production was not possible and the test substance was insoluble in water, a sample of pure test substance was taken for determination of TC. TC analysis was performed at the Chemical Laboratory "Dr. A. Verwey", Rotterdam, the Netherlands using a Varia-analyzer. (Method: Varia El AV/29.007, 1999). TC analysis was not performed under GLP conditions.

Reference substance:

acetic acid, sodium salt

Preliminary study:

None

Test performance:

The positive control substance was degraded at least 60% within 14 days (74%).
The total C02 release in the blank at the end of the test did not exceed 40 mg/1 (49 mg C02 per 2 litres of medium, this is 25 mg/1).
The difference of duplicate values for %-degradation of HATCOL 5236 was always less than 20.
Since all criteria for acceptability of the test were met, this study was considered to be valid.

Key result

Parameter:

% degradation (CO2 evolution)

Value:

67

Sampling time:

28 d

Remarks on result:

other: bottle A

Key result

Parameter:

% degradation (CO2 evolution)

Value:

61

Sampling time:

28 d

Remarks on result:

other: bottle B

Details on results:

The relative degradation values calculated from the measurements performed during the test period revealed 67 and 61% degradation of HATCOL 5236 for bottle A and B respectively. However, biodegradation of HATCOL 5236 of at least 60% was not reached within the 10 day window. Thus, the criterion for ready biodegradability was not met. In the toxicity control more than 25% degradation occurred within 14 days (46%, based onThC02). Therefore, the test substance was assumed to be not inhibitory on microbial activity.

Results with reference substance:

The positive control substance was degraded at least 60% within 14 days (74%).

Monitoring of temperature and pH

The temperature recorded in a vessel with water in the same room varied between 21.6 and 23.4 degrees C.

The pH values of the different test media were:

	Just before the start of the test:	On day 28:
Blank control (A)	7.5	7.3
Blank control (B)	7.5	7.3
Positive control	7.4	7.6
HATCOL 3331 (A)	7.5	7.3
HATCOL 3331 (B)	7.5	7.3
Toxicity control	7.4	7.7

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable, but failing 10-day window

Conclusions:

Read-across substance, HATCOL 5236, was degraded significantly (67 and 61 %) during the test period. However, since at least 60% biodegradation was not reached within the 10-day window, the criterion for ready biodegradability was not met. Thus, under the conditions of this test HATCOL 5236 was not readily biodegradable.

Executive summary:

The study procedure was based on EEC directive 92/69, C.4-C, December 1992, and OECD guideline No. 301 8 July 17, 1992.

The batch of read-across substance, HATCOL 5236, tested was a clear pale yellow liquid and was considered hardly soluble in water. The Total Carbon content (TC) of HATCOL 5236 was determined to be 65.97%. Based on this TC content the Theoretical CO2 production (ThC02) of HATCOL 5236 was calculated to be 2.42 mg CO2/mg.

HATCOL 5236 was tested for its ready biodegradability at 35-36 mg per 21itres, corresponding to 12 mg TC/L.

The study consisted of six bottles:

2 blank controls (no test material),

2 test bottles (HATCOL 5236, 18 mg/L),

1 positive control (sodium acetate, 40 mg/L) and

1 toxicity control (sodium acetate, 40 mg/L; plus HATCOL 5236, 18 mg/L).

Weighed amounts of HATCOL 5236 (test substance bottle A: 35.8 mg; test substance bottle B: 35.0 mg and toxicity control bottle: 36.4 mg) were mixed with 10 ml of milli·RO water. After vigorous shaking the resulting suspension was added quantitatively to the test medium containing the microbial organisms. The test solutions were continuously stirred during the test, to ensure optimal contact between the test substance and the test organisms.

The relative degradation values calculated from the measurements performed during the test period revealed 67 and 61% degradation of HATCOL 5236 for bottle A and B respectively. However, biodegradation of HATCOL 5236 of at least 60% was not reached within the 10·day window. Thus, the criterion for ready biodegradability was not met. In the toxicity control HATCOL 5236 was found not to inhibit microbial activity.

Since all acceptability criteria prescribed by the protocol were met, this study was considered to be valid

In conclusion, HATCOL 5236 was not readily biodegradable under the conditions of the modified Sturm test presently performed.

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

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

Remarks:

3 substances available for read across

Adequacy of study:

weight of evidence

Justification for type of information:

see the attached justification in section 13 for the full details.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Parameter:

% degradation (CO2 evolution)

Value:

>= 18 - <= 22

Sampling time:

28 d

Remarks on result:

other: bottle A and bottle B

Remarks:

Hatcol 3331

Key result

Parameter:

% degradation (CO2 evolution)

Value:

>= 61 - <= 67

Sampling time:

28 d

Remarks on result:

other: bottle A and bottle B

Remarks:

Hatcol 5236

Key result

Parameter:

% degradation (CO2 evolution)

Value:

>= 62 - <= 64

Sampling time:

28 d

Remarks on result:

other: After driving off any inorganic carbonates found (addition of HCl)

Remarks:

Reaction product of pentaerythritol and trimethylolpropane with n-pentanoic acid, 2-methylbutyric acid, n-heptanoic acid, 3,5,5-trimethylhexanoic acid, n-octanoic acid and n-decanoic acid

Validity criteria fulfilled:

not applicable

Remarks:

read across

Interpretation of results:

not readily biodegradable

Conclusions:

The read across for substance, CAS: 156558-98-4; EC: 451-190-0; is based upon the analogous substances to which basic form, degree of substitution of functional groups is not considered to effect the proposed read across for the endpoint of biodegradation. Based on the available information from the read across substances, the substance subject to registration is considered to be readily biodegradable.

Reference 4

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP - Guideline study, tested with the source substance Reaction product of pentaerythritol and trimethylolpropane with n-pentanoic acid, 2-methylbutyric acid, n-heptanoic acid, 3,5,5-trimethylhexanoic acid, n-octanoic acid and n-decanoic acid. According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (ECHA, 2012)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.3110 (Ready Biodegradability)

GLP compliance:

yes (incl. QA statement)

Remarks:

The Department of Health of the Government of the United Kingdom, date of inspection: 22 Jan 1996

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: obtained from the aeration stage of the Severn Trent Water Plc sewage treatment plant at Belper, Derbyshire, UK.
- Preparation of inoculum for exposure: sample of the activated sewage sludge was washed three times by settlement and resuspension in culture medium to remove any excessive amounts of dissolved organic carbon (DOC) that may have been present.

Duration of test (contact time):

28 d

Initial conc.:

10 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: OECD recommended culture medium
- Test temperature: 21 °C
- Suspended solids concentration: 30 mg/L
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 5000 mL closed glass vessels containing a total volume of test solution of 3000 mL
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: Aerated with CO2-free air
- Measuring equipment: an Ion ics 1 555B TOC analyser and a Dohrmann DC-i 90 TOC analyser
- Details of trap for CO2: A carbon dioxide absorbing system comprising two 500 mL Dreschel bottles each containing 350 mL of 0.05 M NaOH.

SAMPLING
- Sampling frequency: on day 0, 1, 2, 3, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 27, 28 and 29
- Sample storage before analysis: frozen at -20 °C prior to analysis.

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

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (CO2 evolution)

Value:

62

Sampling time:

28 d

Key result

Parameter:

% degradation (CO2 evolution)

Value:

64

Sampling time:

29 d

Remarks on result:

other: After driving off any inorganic carbonates found (addition of HCl)

Details on results:

The test material attained 62% degradation after 28 days.

Results with reference substance:

91% degradation after 28 days

The test material attained 62% degradation after 28 days.

Since the substance is a UVCB substance and consists of structurally similar constituents with [e.g. different chain-lengths], sequential (instead of concurrent) biodegradation of the individual structures can take place, but all can be considered as readily biodegradable. Thus, referring to Annex I of the OECD Guideline for Testing of Chemicals ‘Revised introduction to the OECD guidelines for testing of chemicals, section 3’ (OECD, March 2006), the 10-day window should not be considered for this UVCB substance and due to a degradation of >60 % within 28 days the substance can be regarded as readily biodegradable.

Table 1: Percentage biodegradation values

Day	% Degradation Sodium benzoate	Test substance (% degradation)	Test substance + Sodium benzoate Toxicity control (% degradation)
0	0	0	0
1	24	5	12
2	53	17	26
3	59	23	33
6	62	25	43
8	66	39	46
10	72	39	56
14	76	42	63
16	79	46	66
20	80	48	67
22	81	50	70
24	86	59	77
27	89	62	80
28	91	62	81
29*	92	64	81

* Day 29 values corrected to include and carry-over of CO2 detected in Adsorber 2

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Description of key information

The read across for substance, CAS: 156558-98-4; EC: 451-190-0; is based upon the analogous substances to which basic form, degree of substitution of functional groups is not considered to effect the proposed read across for the endpoint of biodegradation. Based on the available information from the read across substances, the substance subject to registration is considered to be readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Additional information

The relative degradation values for read-across substance, HATCOL 3331, calculated from the measurements performed during the test period, revealed 22 and 18% degradation for bottle A and B respectively. Since biodegradation of HATCOL 3331 of at least 60% was not reached within 10 days after exceeding 10%, the criterion for ready biodegradability was not met. In conclusion, HATCOL 3331 was not readily biodegradable under the conditions of the modified Sturm test presently performed.

The relative degradation values for HATCOL 5236, calculated from the measurements performed during the test period, revealed 67 and 61% degradation for bottle A and B respectively. However, biodegradation of HATCOL 5236 of at least 60% was not reached within the 10·day window. Thus, the criterion for ready biodegradability was not met. In the toxicity control HATCOL 5236 was found not to inhibit microbial activity.

Since all acceptability criteria prescribed by the protocol were met, this study was considered to be valid

In conclusion, HATCOL 5236 was not readily biodegradable under the conditions of the modified Sturm test presently performed.

Since no studies investigating the ready biodegradability of Pentaerythritol tetraesters of n-C5, n-C7, n-C8, i-C9 and n-C10 fatty acids (EC 451-190-0) are available for this endpoint, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 a read across to the structurally related source substance Reaction product of pentaerythritol and trimethylolpropane with n-pentanoic acid, 2-methylbutyric acid, n-heptanoic acid, 3,5,5-trimethylhexanoic acid, n-octanoic acid and n-decanoic acid was conducted. The source substance is characterized as an ester of pentaerythritol/trimethylolpropane with fatty acid C-chains of C5, C7, C8, C9iso and C10 whereas the target substance is solely a pentaerythritol ester but esterified with fatty acids of the same C-chain lengths and a slightly different composition. Due to the very similar composition of both substances the source substance can thus be used for read-across to evaluate the biodegradation potential of the target substance.

The key study with the source substance Reaction product of pentaerythritol and trimethylolpropane with n-pentanoic acid, 2-methylbutyric acid, n-heptanoic acid, 3,5,5-trimethylhexanoic acid, n-octanoic acid and n-decanoic acid was performed according to OECD 301B (GLP) under aerobic conditions using domestic activated sludge. The test substance (1000 mg/L) was degraded to and extent of 62% after 28 d. Since the substance is a UVCB substance and consists of structurally similar constituents with [e.g. different chain-lengths], sequential (instead of concurrent) biodegradation of the individual structures can take place, but all can be considered as readily biodegradable. Thus, referring to Annex I of the OECD Guideline for Testing of Chemicals ‘Revised introduction to the OECD guidelines for testing of chemicals, section 3’ (OECD, March 2006), the 10-day window should not be considered for this UVCB substance and due to a degradation of > 60 % within 28 days the substance can be regarded as readily biodegradable.

Based on the results from a structurally similar source substance (in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5) it can be concluded that Pentaerythritol tetraesters of n-C5, n-C7, n-C8, i-C9 and n-C10 fatty acids with pentaerythritol is readily biodegradable according to the OECD criteria.