[No public or meaningful name is available]

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:

August 3-August 31, 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2021

Report date:

2021

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

6-Hydroxy-2,6-dimethylheptan-1-al

Cas Number:

62439-42-3

Molecular formula:

C9H18O2

IUPAC Name:

6-Hydroxy-2,6-dimethylheptan-1-al

Test material form:

liquid

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): aeration tank of sewage treatement plant in Kurume-shi, Fukuoka, Japan
- Storage conditions: aerated at 22 degrees C
- Storage length: 1 day
- Concentration of sludge: 30 mg/L
- Initial cell/biomass concentration: 2040 mg/L

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:

DOC removal

Details on study design:

TEST CONDITIONS
- Composition of medium: Mineral medium made according to test guidelines
- Test temperature: 22 +/- 1 degrees C
- pH: 7.4
- pH adjusted: yes
- Suspended solids concentration: 30 mg/L
- Continuous darkness: yes


TEST SYSTEM
- Culturing apparatus: glass vessel
- Number of culture flasks/concentration: 6
- Measuring equipment: TOC analyzer
- Test performed in closed vessels due to significant volatility of test substance: yes

SAMPLING
- Sampling frequency: at end of incubation (28 days)


CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Toxicity control: yes

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

Test performance:

All validity criteria were met.

% Degradation

Key result

Parameter:

% degradation (DOC removal)

Value:

96

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

The reference substance was biodegraded 90% in 28 days.

Any other information on results incl. tables

	Test Vessel 1	Test Vessel 2	Average
Percentage Biodegradation by BOD Day 7	43	32
Percentage Biodegradation by BOD Day 14	60	52
Percentage Biodegradation by BOD Day 28	79	74	77
Percentage Biodegradation by DOC Day 28	97	94	96

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

The test substance biodegraded 77% (BOD) in 28 days, but did not meet the 10-day window and thus is inherently biodegradable.

Executive summary:

The biodegradation of the test substance hydroxymelonal was determined in an OECD Guideline 301F experiment.  Activated sludge was exposed to 100 mg/L of test substance for 28 days.  Inoculum blanks, toxicity controls, and positive controls were also performed. The test substance biodegraded 57% in ten days after attaining 10% degradation, thus not meeting the 10-day window requirement.  The test substance biodegraded 77% (BOD) in 28 days.  The test substance is therefore inherently biodegradable.