Phosphoric acid, C8-16-alkyl esters, reaction products with (Z)-N-9-octadecenyl-1,3-propanediamine

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

5 July 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Phosphoric acid, C8-16-alkyl esters, reaction products with (Z)-N-9-octadecenyl-1,3-propanediamine

EC Number:

291-909-3

EC Name:

Phosphoric acid, C8-16-alkyl esters, reaction products with (Z)-N-9-octadecenyl-1,3-propanediamine

Cas Number:

90506-47-1

Molecular formula:

complex substance

IUPAC Name:

Phosphoric acid, C8-16-alkyl esters, reaction products with (Z)-N-9-octadecenyl-1,3-propanediamine

Test material form:

liquid: viscous

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and batch No.of test material: PCAS Batch No 80555E094
- Expiration date of the lot/batch: 05/12/2018
- Date pf ma,ufacture: 05/12/2017
- Purity test date: 23/01/2018

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Between 0 and 50°C. Keep away from humidity in a cool, well-ventilated place.
- Stability under test conditions: Yes

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
Due to the properties of the test item (sticky substance), administration of the test item was accomplished with addition onto a solid support. For this purpose, an appropriate amount of test item was weighed onto a glass coverslip. The test item/support combination was then added to the respective test vessels. The vessels were thereafter completely filled with the inoculated mineral medium (300 mL of test medium) in order to obtain a nominal concentration of 5 mg test item/L, and were then closed. No small bubble was observed in the test vessels.

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

natural water: freshwater

Details on inoculum:

- Source of inoculum: River water was sampled from “La Mourachonne”, situated downstream of a plant treating domestic wastewater (Pegomas, France).
- Pretreatment: The river water was aerated for about 7 days before use as inoculum at the test temperature to reduce endogenous respiration.
- Concentration: A concentration of inoculum of approximately 104 cells.L-1 was used.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

5 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium:
The mineral medium was prepared by adding one mL of each of the following stock solutions (a to d) to each litre of ultrapure water:
Stock solutions (a):
KH2PO4 = 8.50 g.L-1
K2HPO4 = 21.75 g.L-1
NA2HPO4. 2H2O = 33.40g.L-1
NH4Cl = 0.50 g.L-1
Stock solutions (b):
CaCl2. 2H2O = 36.40 g.L-1
Stock solutions (c):
MgSO4. 7H2O = 22.50 g.L-1
Stock solutions (d):
FeCl3. 6H2O = 0.25 g.L-1
- Solubilising agent: not used. the test item was accomplished with addition onto a solid support.
- Test temperature: Temperatures were situated between 21.5 and 22.0°C throughout the test (average value: 21.7°C), and complied with the requirements as laid down in the study plan (22°C ± 2°C, constant within 1°C).
- pH: The pH of this solution was approximately 7.5.
- pH adjusted: no
- Continuous darkness: yes


TEST SYSTEM
- 10 bottles containing inoculum and mineral medium (inoculum blank)
- 10 bottles containing test item, inoculum, and mineral medium (test suspension)
- 6 bottles containing reference substance, inoculum and mineral medium (procedure control)
- 6 bottles containing test item, reference substance, inoculum and mineral medium (toxicity control)

Reference substance

Reference substance:

benzoic acid, sodium salt

Remarks:

Manufacturer: VWR. Batch No. 16E234106

Results and discussion

Preliminary study:

In this study, test item was biodegraded by 8% at day 28.

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

8

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

The biodegradation percentage of the reference substance, sodium benzoate, was 80% at day 14, confirming the suitability of the inoculum used.

Any other information on results incl. tables

In this study, test item was biodegraded by 8% at day 28.

The dissolved oxygen concentrations (mg.L-1) throughout the test is presented in the following table:

	Time (days)
	0	7	14	21	28
Inoculum Blank Mean	8.42	7.80	7.64	6.95	6.92
	8.38	7.79	7.49	6.94	7.09
	8.40	7.80	7.57	6.95	7.01
Test Suspension (5 mg test item.L^-1)	8.37	7.70	7.33	6.86	6.79
	8.43	7.78	7.36	6.72	7.00
Mean	8.40	7.74	7.35	6.79	6.90
Procedure Control (2 mg reference substance.L^-1)	8.35	5.25	4.89	N.A.	N.A.
	8.38	5.19	4.83	N.A.	N.A.
Mean	8.37	5.22	4.86	N.A.	N.A.
Toxicity Control (2 mg reference substance.L^-1 + 5 mg test item.L^-1)	8.31	5.02	4.81	N.A.	N.A.
	8.38	5.16	4.37	N.A.	N.A.
Mean	8.35	5.09	4.59	N.A.	N.A.

N.A. : Not applicable

The calculated ThOD of the reference substance sodium benzoate was calculated from its empirical formulae to be:

C7H5O2Na, MW = 144.10 g.mol-1

ThOD = 1.67 mgO2.mg-1

The chemical oxygen demand (COD) value determined by analysis was 240000 mg O2.L-1; since the density of the test item is 917 kg/m3 (CoA data), the recalculated COD value was: COD/density = 240000/917000 = 0.262 mg O2.mg-1.

The biodegradation after n days of the test was calculated as the ratio of the biochemical oxygen demand (BOD) to the theoretical oxygen demand (ThOD) as follows:

% degradation = [BOD (mg O2 .mg test chemical-1) / ThOD or COD (mg O2.mg test chemical-1)] x100

with BOD = [(a(o) - a(n)) - (mb(o) - mb(n))] / mg test chemical.L -1 in vessel

and where:

n = number of days after the start of the test

a(0) = test chemical value at day 0

a(n) = test chemical value at day n

mb(0) = mean inoculum blank value at day 0

mb(n) = mean inoculum blank value at day n.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

According to the OECD 301 guidelines, substances are considered to be readily biodegradable in the closed bottle test if the degradation of the test item is equal to or greater than 60% (based on ThOD) in the ten-day window within the 28-day period of the test (the 10-day window begins when the degree of biodegradation has reached 10% of the ThOD). In this study, test item was biodegraded by 8% at day 28.
Therefore, ARCOT 3135 cannot be considered as readily biodegradable under the experimental conditions.

Executive summary:

A study was performed to assess the biotic degradation of test item ARCOT 3135 by performing a ready biodegradability test. The method followed was designed to be compliant with OECD Guideline for Testing of Chemicals No. 301 D, "Ready biodegradability – Closed Bottle Test".

BOD bottles were filled with mineral medium inoculated with river water and test item added at a nominal concentration of 5 mg.L-1. In the meantime, blanks were filled with inoculated mineral medium. Furthermore, bottles containing reference substance sodium benzoate (2 mg.L-1) were tested in order to check the procedure. A toxicity control, containing both the test item and the reference substance, was also performed in order to check the absence of test item effect on the microbial inoculum. The concentrations of dissolved oxygen in duplicate bottles from each group incubated at 22°C ± 2°C in darkness were measured at the start of the test and thereafter once a week until the end of the test.

The validity of the test was demonstrated by an endogenous respiration <1.5 mgO2.L-1 and by a biodegradation of the reference substance of 80% of its ThOD after 14 days of incubation. Moreover, the differences of the replicate values at day 28 were less than 20% and oxygen concentrations were > 0.5 mg.L-1 in all bottles during the test period. Furthermore, the toxicity control showed that the test item had no inhibitory effect on the activity of the microbial inoculum.

In this study, test item was biodegraded by 8% at day 28. Therefore, ARCOT 3135 cannot be considered as readily biodegradable under the experimental conditions.

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