Reaction product of resin acid and rosin acid, 12-Hydroxyoctadecanoic and stearic acid with dipentaerythritol

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:

9. February - 8. April 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 7-7-B
- Expiration date of the lot/batch: 1 August 1999
- Purity test date: not stated

RADIOLABELLING INFORMATION (if applicable)
not applicable

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature
- Stability under test conditions: assumed stable
- Solubility and stability of the test substance in the solvent/vehicle: minimum of 4 hours
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: not stated

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
none

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Type: Microorganisms from a domestic wastewater treatment plant
Source: ARA Ergolz II, FOllinsdorf I Switzerland
Conditioning: The sludge was washed by centrifugation, the supernatant liquid phase was
decanted and the solid material resuspended in tap water. This procedure
was repeated at least twice. An aliquot of the final sludge suspension was
weighed, thereafter dried and the ratio of wet to dry weight was calculated.
Based on this ratio, calculated amounts of wet sludge were suspended in
test medium (see below) to obtain a concentration equivalent to 4 g
(± 10%) per litre (dry weight basis). During holding the sludge was aerated
at room temperature until use. Prior to use the sludge was diluted with test
medium to a concentration of 1 g per litre (dry weight basis). A defined
volume of this diluted activated sludge was added to the test flasks to obtain
a final concentration of 30 mg mixed liquor suspended solids (MLSS) per
litre.

Duration of test (contact time):

28 d

Initial conc.:

>= 92 - <= 108 mg/L

Based on:

COD

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Apparatus:
The test flasks (500 ml Erlenmeyer-shaped flasks) were labelled with the
necessary information to assure unmistakable identification and
incubated under continuous stirring on a SAPROMAT 012 (Voith GmbH).
Oxygen consumption was recorded manually by taking a daily reading
during working days.

Light regimen: Darkness
Test temperature: 22 C, maintained with a built-in thermostat and checked once per week.
pH: Prior to test start the pH was measured in all test flasks after the addition
of the activated sludge (inoculum). At the end of incubation the pH was
measured in all test flasks.

Test Medium
The test medium was prepared according to the testing guidelines. The stock solutions were
as follows:
a) 8.5 g KH2PO4, 21.75 g K2HPO4, 33.4 g Na2HPO4 x 2H2O, 0.5 g NH4CI dissolved in
purified water and made up to 1000 ml with purified water. The pH was 7.4.
b) 22.5 g MgS04 x 7H20 dissolved in purified water and made up to 1000 ml with purified
water.
c) 36.4 g CaCl2 x 2H20 dissolved in purified water and made up to 1000 ml with purified
water.
d) 0.25 g FeCb x 6H20 dissolved in purified water and made up to 1000 ml with purified
water. In order to avoid having to prepare this solution immediately before use, one drop
of concentrated HCI per litre was added.
Ten ml of stock solution a) and one ml each of stock solutions b)-d) were combined and
made up to 1000 ml with purified water. The pH was adjusted to 7.4 with a diluted
hydrochloric acid solution.

Reference substance:

benzoic acid, sodium salt

Test performance:

After correction for the mean biochemical oxygen demand (BOD) of the inoculum controls
(flasks 1 and 2) the BOD of the test article in test flasks 3 and 5 was 98 and 85 mg O2/I at the
end of the 28-day exposure period, resulting in degradation rates of 35 % and 36 % of COD,
respectively, or a mean of 35 %. Consequently, the test article was found to be moderately
biodegradable under the test conditions within 28 days.
Abiotic control:
The BOD of the noninoculated flask 8, containing the test article and poisoned test medium,
was only 2 mg O2/l by the end of the 28-day exposure period. Consequently, no significant
abiotic degradation of the test article occurred.

Key result

Parameter:

% degradation (O2 consumption)

Value:

>= 35 - <= 36

Sampling time:

28 d

Details on results:

Validity:
The validity of the test was fulfilled because of the following:
The oxygen demand of the inoculum controls (flasks 1 and 2) at the end of the test was 8 and
15 mg O2/l, respectively, and thus lower than 60 mg O2/l.
The difference of the degradation rates between the test article-treated flasks (flasks 3 and 5)
was <20 % at the end of the test.
The percentage degradation of sodium benzoate in the procedure controls (flasks 4 and 7)
was 81 % and 83 % of the ThOD(NH4) on exposure day 14, and thus higher than 60 %.
The pH measured in the flasks at the end of the test ranged from 7.4 to 8.0, and was thus in
the range 6-8.5.

Key result

Parameter:

COD

Value:

96 - 109 mg O2/g test mat.

Results with reference substance:

The reference substance sodium benzoate was biodegraded by an average of 82 % of
ThOD(NH4) by exposure day 14. At the end of the test (day 28), sodium benzoate was
biodegraded by an average of 83 % of ThOD(NH4); thus confirming suitability of the activated
sludge.

Degradation in the toxicity control
The BOD of the toxicity control (flask 10) containing both the test article and the reference
substance sodium benzoate showed a similar course of biodegradation over the 28-day
exposure period as the two procedure controls (flasks 4 and 7) containing the reference
substance sodium benzoate, only. Expressed as % biodegradation (based on the COD of the
test article and the ThODNH4 of the reference substance) 38 % biodegradation was noted
within 14 days of exposure; thus, according to the test guidelines the test article can be
assumed to not be inhibitory because degradation was >25 % within 14 days.

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

The substance Salacos 168 ARV was found to be moderately (inherently) biodegradable under the test conditions reported.

Executive summary:

The test article DIPENTAERYTHR汀YL HEXAHYDROXYSTEARATE/STEARATE/

ROSINATE was investigated for its biodegradability in the “Manometric Respirometry Test"

over a period of 28 days.

The BOD of the test article was 98 and 85 mg O2/l at the end of the 28-day exposure period,

resulting in degradation rates of 35 % and 36 % of COD, respectively, or a mean of 35 %.

Consequently, the test article was found to be moderately biodegradable under the test

conditions within 28 days.

The reference substance sodium benzoate was biodegraded by an average of 82 % of

ThOD(NH4) on exposure day 14, and reached an average biodegradation rate of 83 % of

ThOD(NH4) by the end of the test (day 28); thus confirming suitability of the activated sludge.

In the toxicity control, containing both the test article and the reference substance sodium

benzoate, no inhibitory effect on the activated sludge was observed.

Description of key information

one Guideline study available

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable

Type of water:

freshwater