2-hydroxy-N-[(2S,3S,4R)-1,3,4-trihydroxyoctadecan-2-yl]benzamide

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:

2007-07-13 to 2007-08-16

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted 1992-07-17

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

2-hydroxy-N-[(2S,3S,4R)-1,3,4-trihydroxyoctadecan-2-yl]benzamide

EC Number:

855-895-8

Cas Number:

212908-67-3

Molecular formula:

C27H47NO5

IUPAC Name:

2-hydroxy-N-[(2S,3S,4R)-1,3,4-trihydroxyoctadecan-2-yl]benzamide

Test material form:

solid: bulk

Details on test material:

Purity: > 99.8%
Lot No.: C928/06/4/1

Specific details on test material used for the study:

As the test substance is not water soluble or homogeneously suspendable in water it was directly weighed into the 3 test vessels, so that the final concentration was 100 mg/L in inoculated mineral medium.

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

A fresh sample of activated sludge from the aeration basin of a municipal sewage treatment plant
(Moers, Germany) was collected and aerated until usage. The inoculum was not fed during the aeration period.
The duration of the aeration period was 1 day.
After determination of the suspended solids (dry wweight) a sample containing 1875 mg suspended solids was
filtered by means of a water jet was washed twice with mineral medium. Afterwards, it was suspended
in 250 mL mineral medium and stirred until it was homogeneous. 4 mL of this suspension were used to
inoculate 1 liter of mineral medium. This amount of inoculum corresponded to 30 mg/L suspended solids.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

100 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: Mineral salts medium according to OECD 301 F
- Test temperature: 22 °C
- pH: 6.0 - 8.5
- Continuous darkness: yes
TEST SYSTEM, CONTROL AND BLANK SYSTEM
- Culturing apparatus: vessels
- Number of culture flasks/concentration:
three for the blank control
two for the abiotic control (test substance + HgCl2)
two for the reference substance (sodium benzoate)
three for the test substance
two for the toxicity control (test substance + sodium benzoate)
- Method used to create aerobic conditions: aeration 1 days
- Inhibition of nitrification: addition of N-allylthiourea (N-ATH)
- Laboratory equipment:
Digital Respirometer System, Sensomat system, Liebherr, Aqualytic, Langen, Germany
pH-Meter, WTW, Weilheim Germany
heater device: CSB Thermostat, Ströhlein Instruments, Germany
titration device: 686 Titroprocessor, Metrohm, Herisau, Schwitzerland
normal laboratory equipment

For further details on test system, please see section “any other information on materials and methods incl. tables”.

Reference substance

Reference substance:

benzoic acid, sodium salt

Remarks:

100 mg/L

Results and discussion

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

80

Sampling time:

28 d

Remarks on result:

other: biodegradation rate as % BOD

Details on results:

For a detailed description of results, please see section "any other information on results incl. tables".

BOD5 / COD results

Results with reference substance:

The reference substance was biodegraded to 89% within 14 days.

Any other information on results incl. tables

The following biodegradation rates were reached:

Test vessel (No.)	Test compound	Degradation rate in [%] 14d	Degradation rate in [%] 10d window day 4 – day 14	Degradation rate in [%] 28d	Mean value±standard deviation [%]
4	100 mg/L test substance (abiotic control)	n.r.	n.r.	-1
5	100 mg/L test substance (abiotic control)	n.r.	n.r.	-1	-1 / 0
6	100 mg/L sodium benzoate	89	n.r.	99
7	100 mg/L sodium benzoate	89	n.r.	94	96 /±4
8	100 mg/L test substance	n.r.	52	72
9	100 mg/L test substance	n.r.	61	84
10	100 mg/L test substance	n.r.	63	84	80 /±7
11	100 mg/L test substance + 100 mg/L sodium benzoate	60	n.r.	77
12	100 mg/L test substance + 100 mg/L sodium benzoate	57	n.r.	71	74 /±4

n.r. = not relevant

Biodegradation rates of the test substance N-Salicyloyl-Phytosphingosine were calculated on the basis of its Chemical Oxygen Demand, which was 1663 mg Oxygen per gram (Study No. 17041, Work and Final Report No. 405/2007).

Biodegradation rates of the reference substance sodium benzoate were calculated on the basis of its Chemical Oxygen Demand, which was 1638 mg Oxygen per gram (Study No. 16350, Work and Final Report No. 71/2005).

Mean values of biodegradation for the test substance as determined in a manometric respiratory test:

	Biodegradation in % of COD
	10 day window / Biodegradation after 14 days	Biodegradation after 28 days
Test substance1	59	80
Reference Substance2	89	96
Toxicity Control2	58	74
Abiotic control	Not relevant	-1

1 = 10 day window applies, 2 = biodegradation after 14 days applies

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

N-Salicyloyl-Phytospingosine is classified as readily biodegradable within the 28 day period of the study, but failing the 10-day window.

Executive summary:

The ready biodegradability of N-Salicyloyl-Phytospingosine was determined with non-adapted activated

sludge in the Manometric Respirometry Test for a period of 28 days. The study was conducted

according to OECD guideline 301 F. The concentration of N-Salicyloyl-Phytospingosine selected as

appropriate was 100 mg/L. The oxygen was depleted by the respiration of bacteria

and the degradation was followed by measuring the oxygen concentration. The biodegradation

rate is therefore expressed as the percentage BOD (biological oxygen demand) and was

calculated for each study day.

Sodium benzoate was used as reference substance. The pass level > 60 % was reached.

The functional capability of the inoculum was sufficient, as the reference substance sodium

benzoate was biodegraded to an average of 89% within 14 days.

The test substance is not assumed to be inhibitory, because 58% degradation accured within

14 days in the toxicity control preparations containing 100 mg test substance and 100 mg sodium benzoate per liter.

The average degradation value of the test substance was 80% after 28 days. The test substance

was biodegraded to 59% in a 10-d window (day 4-14) within the 28-d period at the recommended concentration of 100 mg/L.

N-Salicyloyl-Phytospingosine is classified as readily biodegradable within the 28 day period of the study,

but failing the 10-day window.