Cyclohexanemethanol, 4-(1-methylethyl)-

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:

October 23, 2012 to November 22, 2012

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)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Inspected on February 22 and 23, 2011 and signed on September 19, 2011.

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Secondary treatment stage of the sewage treatment plant at Villette (STEP Villette, av. de Thônex 105, 1226 Thonex (Geneva, Switzerland)).
- Storage conditions: maintained on continuous aeration upon receipt
- Preparation of inoculum for exposure: a sample was washed three times by settlement (centrifuge: Heittich rotenta 460 RS) and suspension in culture medium.
- Concentration of sludge: 30 mg/L dry weight activated sludge

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Additional substrate: None
- Solubilising agent (type and concentration if used): None
- Test temperature: 22±1°C

TEST SYSTEM
- Culturing apparatus: 1000 mL glass culture vessels
- Number of culture flasks/concentration: control: 2, test material: 3, reference material: 1, toxicity control: 1

SAMPLING
- Sampling frequency: daily BOD values for the control, test material, reference material, and toxicity control
- Sampling method: sample flask sealed by a sensor head/CO2 trap attached to WTW oxitopC to automatically calculate the consumption of oxygen

CONTROL AND BLANK SYSTEM
- Inoculum blank: in duplicate, consisting of inoculated culture medium
- Toxicity control: the test material and the reference material in inoculated culture medium

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (O2 consumption)

Value:

91

Sampling time:

28 d

Remarks on result:

other: test 1

Key result

Parameter:

% degradation (O2 consumption)

Value:

72

Sampling time:

28 d

Remarks on result:

other: test 2

Key result

Parameter:

% degradation (O2 consumption)

Value:

74

Sampling time:

28 d

Remarks on result:

other: test 3

Details on results:

The toxicity test attained 65% degradation after 28 days thereby confirming that the test material was not toxic to the sewage treatment micro-organisms used in the study.

Results with reference substance:

Sodium benzoate attained 91% degradation after 28 days.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The test material (test 1, 2, 3) attained respectively 91%, 72%, and 74% degradation (average 79%) after 28 days and all of them reached the 10d window.
Therefore as all validation criteria are fulfilled, the test material can be considered to be readily biodegradable under the strict terms and conditions of OECD 301F.

Executive summary:

A ready biodegradability was tested according to OECD 301F (Manometric Respirometry) in 2012 (Firmenich Biodegradation Laboratory, 2012).  The initial test substance concentration was 100 mg/L, and the test was performed with activated sludge, non-adapted. Oxygen consumption was monitored over a time period of 28 days. Standard test results showed that the test material (test 1, 2, 3) attained respectively 91%, 72%, and 74% degradation after 28 days and all of them reached the 10d window. As all validation criteria were fulfilled, the test material can be considered to be readily biodegradable under the strict terms and conditions of OECD 301F.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

Feb. 2, 1981 - June 10, 1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Standard test using a method similar to MITI

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Deviations:

not specified

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

natural water / sediment

Details on inoculum:

- Initial cell/biomass concentration: 30 ppm

Duration of test (contact time):

28 d

Initial conc.:

100 other: ppm

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation:

DOC removal

Parameter followed for biodegradation estimation:

test mat. analysis

Remarks:

GC method

Details on study design:

TEST CONDITIONS
- Composition of medium: Test substance as the sole carbon source
- Additional substrate: None
- Test temperature: 25 Centigrade
- pH: At end of test: water phase: 5.4; Sludge phase: 6.7
- pH adjusted: no

TEST SYSTEM
- Culturing apparatus: Flasks
- Number of culture flasks/concentration: 3 (100 ppm)
- Measuring equipment: Shimadzu TOC- 10B; Hitachi GC with FID detector;
- Test performed in closed vessels: Yes

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes
- Abiotic sterile control: Yes
- Toxicity control: No
- Positive control: YES (aniline)

Reference substance:

aniline

Preliminary study:

not applicable.

Test performance:

Any deviation from the test procedure applied has been identified.

Key result

Parameter:

% degradation (O2 consumption)

Value:

57

Sampling time:

28 d

Remarks on result:

other: non-enchanced test: 30 ppm sludge, 100 ppm test substance

Parameter:

% degradation (DOC removal)

Value:

55

Sampling time:

28 d

Remarks on result:

other: non-enhanced test: 30 ppm sludge, 100 ppm test substance

Parameter:

% degradation (test mat. analysis)

Value:

100

Sampling time:

28 d

Remarks on result:

other: non-enhanced test: 30 ppm sludge, 100 ppm test substance

Key result

Parameter:

% degradation (DOC removal)

Value:

95

Sampling time:

14 d

Remarks on result:

other: Enhanced test: 100 ppm sludge, 30 ppm test substance

Parameter:

% degradation (test mat. analysis)

Value:

100

Sampling time:

14 d

Remarks on result:

other: Enhanced test: 100 ppm sludge, 30 ppm test substance

Details on results:

Non-enchanged test:
32% degradation by O2 conumption after 14 days
57% degradation by O2 consumpiton after 28 days
55% degradation by DOC removal after 28 days
100% degradation by test material analysis (TOC) after 28 days

Enhanced test:
95% degradation by DOC removal after 14 days
100% degradation by test material analysis (TOC) after 14 days

Results with reference substance:

63% DOC die away

Validity criteria fulfilled:

not applicable

Interpretation of results:

inherently biodegradable

Conclusions:

The test results showed the substance was not readily biodegraded, under the non-enhanced test conditions. However, the enhanced biodegradation test showed the test substance degraded fast at the end (14 d). Thus the substance is regarded as inherently biodegradable.

Executive summary:

This study was conducting following a methodology similar to OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I)) using natural water/sediment. The non-enhanced test results showed the substance was not readily biodegradable. However, the enhanced biodegradation test showed the test substance degraded fast at the end (14 d). Thus the substance is regarded as inherently biodegradable.

 

As this study was conducted using an inoculum derived solely from natural water and sediment, with no activated sewage sludge component, the conditions are considered to have been excessively severe.

Description of key information

OECD 301F (Manometric Respirometry) test was conducted to characterize the biodegradation potential of the substance. The test material (test 1, 2, 3) attained respectively 91%, 72%, and 74% degradation (average 79%) after 28 days and all of them reached the 10d window.

Therefore as all validation criteria are fulfilled, the test material can be considered to be readily biodegradable under the strict terms and conditions of OECD 301F.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

A ready biodegradability was tested according to OECD 301F (Manometric Respirometry) in 2012 (Firmenich Biodegradation Laboratory, 2012).  The initial test substance concentration was 100 mg/L, and the test was performed with activated sludge, non-adapted. Oxygen consumption was monitored over a time period of 28 days. Standard test results showed that the test material (test 1, 2, 3) attained respectively 91%, 72%, and 74% degradation after 28 days and all of them reached the 10d window.

In a supporting study, conducted following a methodology similar to OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I)) in 1981 by the Chemical Inspection and Testing Institute, the substance was shown to reach only 55% degradation in 28 days. However, the inoculum used was derived solely from natural water and sediment, with no activated sewage sludge component, so the test conditions are considered to have been excessively severe.

As all of the validation criteria are fulfilled following a GLP OECD 301F compliant study using non-adapted activated sludge, the test material can be considered to be readily biodegradable under the strict terms and conditions of OECD 301F.