Fatty acids, tall-oil, magnesium salts

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:

2005-08-01 - 2005-09-02

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Justification for read-across, see attached file.

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Remarks:

Activated sludge from the municipal sewage treatment plant in Reutlingen

Key result

Parameter:

other: BOD5*100/COD

Value:

>= 68.1

Sampling time:

14 d

Key result

Parameter:

other: BOD5*100/ThOD

Value:

>= 81.9

Sampling time:

28 d

Key result

Parameter:

BOD5*100/COD

Value:

68.1 other: percent

Remarks on result:

other: % for 14 Days

Remarks:

% Biodegradation = 100 x (BOD (mg O /mg test article)/ COD (mg O /mg test article))

Key result

Parameter:

BOD5*100/ThOD

Value:

81.9 other: %

Remarks on result:

other: % for 28 Days

Remarks:

% Biodegradation = 100 x (BOD (mg O /mg test article)/ ThOD (mg O /mg test article))

Results with reference substance:

- Biodegradation after 14 days: 94,2 %

- Biodegradation after 28 days: 96,6 %

Interpretation of results:

readily biodegradable

Executive summary:

Aim: To determine the “ready biodegradability“ of Crude Tall oil.

Method:

The test is performed at a test temperature of 22 ± 2 °C under aerobic conditions in closed bottles with electrolytic oxygen supply and automatic data registration. Respirometric BOD-determination was carried out with CO2-absorption on soda lime. The test is recommended for water soluble test articles as well as insoluble and volatile test articles.  The concentration of the test article was ca. 100 mg/L.  The concentration of the reference article, Sodium-Benzoate, was ca. 100 mg/L.  

Biodegradability is expressed as the percentage oxygen uptake (corrected for blank uptake) of the Theoretical Oxygen Demand (ThOD) or of the Chemical Oxygen Demand (COD) respectively.

Results:

Biodegradability of test article:

- Test concentration:  109,3 mg/L

- COD of the test article:     2,20 mg O2/mg test article - COD in the test flasks: 240,7 mg O2/L

- BOD in flask 1 after 28 days: 209,9 mg O2/L (including blank) - BOD in flask 2 after 28 days: 210,1 mg O2/L (including blank)  - mean value:  210,0 mg O2/L (including blank) - maximum BOD-difference in flasks 1 + 2 at the    end of the test (required: < 20 %):     0,1  %

- BOD in flask 3 after 28 days (inoculum blank):     6,3 mg O2/L - BOD in flask 4 after 28 days (inoculum blank):   19,5 mg O2/L - mean value inoculum blank (required: < 60 mg O2/L):   12,9 mg O2/L

- BOD in flask 6 after 28 days (abiotic degradation):     0 mg O2/L

- BODtest article - BODinoculum blank - BODtest article abiotic: 197,1 mg O2/L   or      1,80 mg O2/mg test article

- Biodegradation after 14 days:      68,1 %

- Biodegradation after 28 days:      81,9 %

- 10 days window:         63,1  %

Conclusion: CTO Sample 1 of Arizona Chemical achieved 82 % biodegradation in  28 days (10 days window: 63 %) in a Manometric Respirometry Test  conducted according to OECD-Guideline 301 F.   CTO Sample 1 is therefore readily biodegradable.

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:

See justification for read-across further down.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Parameter:

% degradation (DOC removal)

Value:

99

Sampling time:

28 d

Remarks on result:

other: 2-EHA

Key result

Parameter:

% degradation (DOC removal)

Value:

90.1

Sampling time:

7 d

Remarks on result:

other: 2-EHA

Key result

Parameter:

BOD5*100/COD

Value:

68.1 other: percent

Remarks on result:

other: Tall oil

Key result

Parameter:

BOD5*100/ThOD

Value:

81.9 other: percent

Remarks on result:

other: Tall oil

Executive summary:

The target UVCB, Reaction mass of Fatty acids, tall oil, 2-ethylhexanoic acid and magnesium salts is readily biodegradable and will not be classified according to CLP.

CTO Sample 1 of Arizona Chemical achieved 82 % biodegradation in  28 days (10 days window: 63 %) in a Manometric Respirometry Test  conducted according to OECD-Guideline 301 F for Tall oil.   CTO Sample 1 is therefore readily biodegradable. According to OECD guidline 301E, 2-ethylhexanoic acid is readily biodegradable with a biodegradation (28 d) > 70 % and a pass level was reached in 10-d window.

Reference 3

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:

Guideline study with acceptable restrictions (e.g. non-GLP; instead of secondary effluent as recommended by the guideline, the primary effluent of a municipal sewage treatment plant was used as inoculum for this study. The authors justified this by referring (1) to the microbial concentration in the secondary effluent that was too low for the purpose of the study, and (2) to the possible presence of chemical residues within the secondary effluent that may interfere with the biological activity.)

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, domestic (adaptation not specified)

Details on inoculum:

INOCULUM :
- Target concentration of microbes in test solution (OECD 301 E): 10E+05 cells/L
- Origin of the inoculum : Municipal sewage treatment plant , Suomenoja , Espoo 26.05.1998
Concentration of inoculum : 1. Secondary effluent approx. 10E+03 - 10E+04 cells/ml; 2. Primary effluent approx. 10E+06 cells/ml
(Easycult TTC, Orion Diagnostica ); Inoculum 2. was used in the test to obtain sufficient microbe concentration
- Preparation of inoculum : Filtration (Schleicher & Schuell 5891 Black ribbon )
- Addition into test solution : 0.5 ml/I

Duration of test (contact time):

28 d

Initial conc.:

20 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS : Incubation shaker New Brunswick G25-KLC
Continuous shaking 120 rp m
Temperature 22 ± 2 °C
Dark
Test vessels 2 I conical flasks , volume of the test solution at start 1000 ml
Free exchange of air in test vessel s
SAMPLING: DOC-samples 50 ml/sampling time and flask
Filtration of samples with Gelman Ion chromatography Acrodisc 0 .45 pm
Storage of filtered samples in -20 °C before analysis

test series:
inoculum blank (inoculum + mineral medium),
test substance (inoculum + mineral medium + test substance),
reference substance (inoculum + mineral medium + reference substance),
toxicity test (inoculum + mineral medium + test substance + reference substance) - start conditions:

mineral medium: pH 7.6, 9 mg/l O2 (= 100 %),
test substance solution: pH 7.45

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (DOC removal)

Value:

99

Sampling time:

28 d

Parameter:

% degradation (DOC removal)

Value:

90.1

Sampling time:

7 d

Details on results:

RS-Freetext:
Biodegradation (% relate to DOC)

0 d 2 d 5 d 7 d 14 d 28 d
test substance
(mean) 0 67.2 91.4 90.7 94.9 99.2

reference
substance 0 83.8 97.8 95.6 96.8 99.3

toxicity test 0 76.1 98.2



Biodegradation 10 d window
10 % 70 %
test substance 0.3 d 2.3 d 0.3 d - 10.3 d

reference
substance 0.2 d 1.7 d 0.2 d - 10.2 d


Conclusion:
2-ethylhexanoic acid is readily biodegradable:
- biodegradation (28 d) > 70 %
- Pass level reached in 10-d window.

Kinetic of test substance (in %):
= 67 after 2 day(s)
= 91 after 5 day(s)
= 91 after 7 day(s)
= 95 after 14 day(s)
Kinetic of control substance (in %):
= 84 after 2 day(s)
= 98 after 5 day(s)
Degradation products: not measured

Abiotic and adsorption tests were poisoned with 15 mg/l Na azide to prevent bioactivity. The dosage was not sufficient to stop microbial growth in test vessels, and so the tests were interrupted as the preliminary results showed at the same time that these factors are not likely to interfere the biodegradation of the test substance.

test has been performed by Ekolab Environmental Oy (sponsor: Finnish Chemicals Oy)

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Executive summary:

2-ethylhexanoic acid is readily biodegradable:

  - biodegradation (28 d) > 70 %

  - Pass level reached in 10-d window.

Description of key information

The information on biodegradation of the substance is based on read across from Tall oil and 2-ethylhexanoic acid and reveals readily. Furthermore, the source substances contain higher or similar concentrations of the constituents used for read across compared to the target substance. There are no scientific reasons indicating that the constituents of the substance can interact in a way that will influence the toxicological/ecotoxicological properties of the substance.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

CTO Sample 1 of Arizona Chemical achieved 82 % biodegradation in  28 days (10 days window: 63 %) in a Manometric Respirometry Test  conducted according to OECD-Guideline 301 F.   CTO Sample 1 is therefore readily biodegradable. According to OECD guidline 301E, 2-ethylhexanoic acid is readily biodegradable with a biodegradation (28 d) > 70 % and a pass level was reached in 10-d window.