D-Glucitol, 1-deoxy-1-[methyl(1-oxononyl)amino]-

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:

2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

microbial inoculum concentration was 30 mg/L
Activated sludge was obtained from a sewage plant treating predominantly domestic sewage
(Nanjing Chengdong Sewage Treatment Plant).
The sludge was washed with basal mineral salt medium (BSM) by settling the sludge in a
graduated cylinder, decanting the supernatant liquid, replacing with fresh BSM, aerating, and
settling. The above washing process was repeated 3 times and was aerated until use.
Before use, the sludge was centrifuged one time (5000 r/min, 4 °C, 10 minutes) and the
supernatant liquid decanted. Thereafter, a small amount of the washed sludge was weighed and
then dried at 100°C until the weight of the dried sludge did not change significantly anymore.
Then the dry weight percentage of suspended solids (p) of the activated sludge was calculated to
be 8.97%. Finally 22.3 g wet sludge after centrifugation was mixed with 0.5 L BSM to obtain an activated sludge with a mixed liquor suspended solids level of 4
g/L. Cell density was determined to be 6.14x 108 CFU/L using microscope.

Duration of test (contact time):

28 d

Initial conc.:

31.8 mg/L

Based on:

test mat.

Initial conc.:

30.4 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance:

aniline

Parameter:

% degradation (O2 consumption)

Value:

71.5

Sampling time:

28 d

Parameter:

% degradation (O2 consumption)

Value:

66.8

Sampling time:

28 d

Remarks on result:

other: 10-day window

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The results show that under the experimental conditions, biodegradation of the test substance
(Glucamide 9 (GA9)) was71.5% at the end of test, and biodegradation was 66.8% within 10-day
window.

Executive summary:

Accordingto "Theguidelines forthe testing of chemicals",SEPA(HJ/T 153-2004),"The

Guidelines fortheTestingofChemicals, Degradation andAccumulation" (2ndedition), Beijing:

China EnvironmentalPress.2013, "Chemicals-Readybiodegradability-Manometric

respirometrytest" (GB/T21801-2008); andwith referenceto Procedure 301F ofthe"Guidelines

forTestingof Chemicals" ofthe OECD:"Manometric Respirometry Test"(1992),the ready

biodegradabilityofGlucamide9(GA9) was determined in a28-dayoxygen consumption test

(OECD301F)usingactivated sludge from adomestic waste watertreatmentplantas the source

of the microbialinoculum.

The initial concentration of the testsubstancein the reaction vessels was31.8mg/L and30.4

mg/L. The microbial inoculumconcentration(mixed liquorsuspendedsolids) was30mg/L.

During the test, the temperature was kept at (22±1)°C.The pH valueofthe content in the test

container was maintained between 6.84 and7.45.The totaloxygenuptake in the inoculum blank

was22.9mg O₂/Lattheendof thestudy,ranged20~30mg O₂/L.Biodegradationof the

referencesubstance, aniline,reached65.1%at 14 days (>60%).Thedifference between replicate

values was less than20%during thestudy.Biodegradation of inhibitioncontrolwas 40.7%at14

days(>25%), and the oxygen consumption by the testsubstanceisgreaterthan 60% of inoculum

blank during the test period, indicating that there was no inhibitioneffectto inoculum. Thus, the

test was considered valid.

Underthe valid conditions, biodegradation of the test substance (Glucamide 9 (GA9)) was 71.5%

at the end of the28-day study,and biodegradation was 66.8% within10-day window

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

May - June 2017

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)

Deviations:

yes

Remarks:

See Principles of method if other tahn guideline

Principles of method if other than guideline:

The second set of inoculum weights used to confirm the suspended solids concentration in the test vessels, as estimated by the first set of inoculum weights, were discarded prior to the final weights being completed. This did not impact the volume of inoculum added at test initiation.
On one day, the thermometer used for daily temperature monitoring displayed minimum and maximum temperatures outside the test temperatures range, due to loose batteries causing faulty readings. The thermometer continued to operate normally after being reset and batteries were secured. No facility issues occurred at this time to account for this temporary temperature fluctuation.

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

Activated sludge from the Joint Abbotsford Mission Environmental Systems (JAMES) wastewater treatment plant, Abbotsford, BC

Duration of test (contact time):

28 d

Initial conc.:

45 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Mean test Temperature: 21 °C
pH: 7.2 - 7.6
Photoperiod: 24-h dark (expect during daily readings)
Test vessels: 2L flat-bottomed glass media bottles fitted with stoppers
test volume: 1.5 L
2 replicates

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (O2 consumption)

Value:

57

Sampling time:

28 d

Parameter:

% degradation (O2 consumption)

Value:

52

Sampling time:

28 d

Remarks on result:

other: with Nitrification Correction

Results with reference substance:

86% after 28 days

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The test Item cannot be considered readily biodegradable under the test conditions as the Test Item did not surpass 60% biodegradation by the end of the 10-day windows (53%; 48% with nitrification correction). Due to the stringency of this test, test items which do not achieve pass levels may still be biodegradable in the environment.

Executive summary:

The Test Item was tested to asses its degree of ready biodegradability using the procedures outlined in the Maxxam Study Plan which is based on the Standard Operating Procedure (SOP) for Ready Biodegradability: manomentric Respirometry test (OECD, 1992).

Description of key information

Two studies according OECD Guideline 301F are available. In one Study a degradation of 57 % (52 after Nitrification Correction) was found. In the second (KEY Study) a degradation 71.5 % after 28 days and 66.8 % in 10 day window was found.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater