Reaction mass of 1,2,3,4,4a,5,6,7-octahydro-2,5,5-trimethyl-2-naphthol and 4-(2,6,6-trimethyl-1-cyclohexen-1-yl)butan-2-one and 4-(2,6,6-trimethyl-2-cyclohexen-1-yl)butan-2-one

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:

supporting study

Study period:

June 16 2017 - December 22 2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

other: "Method fo Testing the biodegradability of Chemical substances by Microorganisms"

Version / remarks:

stipulated in the "Testing Methods for New Chemical Substances" (March 31, 201 1, No. 0331-7, Pharmaceutical and Food Safety Bureau, Ministry of Health, Labour and Welfare; March 29,201 1, No. 5, Manufacturing Industries Bureau, Ministry of Economy, Trade and Industry; No. 1 1033 1009, Environmental Policy Bureau, Ministry of the Environment, Japan; latest revision, December 21, 2015, No. 1221-1, Pharmaceutical and Food Safety Bureau, Ministry of Health, Labour and
Welfare; December 9,201 5, No. 1, Manufacturing Industries Bureau, Ministry of Economy, Trade and Industry; No. 15 1221 1, Environmental Policy Bureau, Ministry of the Environment, Japan)

GLP compliance:

not specified

Remarks:

Study conducted outside of the EU.

Specific details on test material used for the study:

Name: 2,5,5-Trimethyl-1,2,3,4,4a,5,6,7-octahydronaphthalen-2-ol

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, domestic, non-adapted

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:

Concentration of activated sludge 30 mg/L(as concentration of suspended solid)
Volume of test solution 300 rnL
Incubation conditions 25±2°C, under dark conditions
Incubation duration: 28 days

Reference substance:

aniline

Key result

Parameter:

other: % biodegradation by BOD

Value:

>= 49 - <= 50

Sampling time:

28 d

Parameter:

other: % biodegradation of the test item by GC

Value:

>= 62 - <= 77

Sampling time:

28 d

Details on results:

In the test solutions (sludge + test item)-1, -2 and -3, BOD measured. The percentage biodegradation by BOD was 49-50% and the BOD chart reached plateau after 14 days. The percentage residue of the test item by GC was 23-39% on the basis of the total peak area. The percentage residue of each peak of the test item was also calculated. As a result, the percentage residue of the peak 1 to 3 was disappeatd, that of the peak 4-9 was decreased (19-92%) and the degree of the decrease varied depending on the test solutions. On the other hand, the percentage residue of the peak 10 was 101%. The percentage residue of the peak 11 was 113-146%. The increase of BOD suggested that biodegradation of the peak 1 to 3 of which content ratio was 53% on the basis of the peak area on GC chromatograms. Four peaks in addition to the
test item peaks were detected on GC chromatogram. Therefore, the result indicated that the degradation products were produced by microorganisms in the test solution (sludge + test item).

Validity criteria fulfilled:

not specified

Interpretation of results:

not readily biodegradable

Conclusions:

Under the test conditions of this preliminary test, some of the test item was disappeared and plural degradation products were produced by bidegradaton. The residual test item and the degradation products were remained in the test solution.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1st August 2018 - 29th August 2018

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:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Activated sludge was obtained from an aeration tank of a sewage treatment plant treating predominantly domestic sewage in Kurume-shi Fukuoka, Japan
The activated sludge was aerated at about 22°C until use for the test.

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Details on study design:

Concentration of test item 100 mgL
Concentration of activated sludge 30 mg/L (as concentration of suspended solid)
Volume of test solution 300 mL
Incubation temperature 22+/-1°C
Incubation duration 28 days (under dark conditions)
Observation of test solutions: At the start and the end of the incubation
Measurement of biochemical oxygen demand (BOD): During the incubation period

Reference substance:

benzoic acid, sodium salt

Test performance:

The difference between the maximum value and the minimum value of the percentage biodegradtion by BOD in the test solutions (sludge + test item) did not meet one of the validity criteria (less than 20%). However, it was judged that there was no impacts on quality and integrity of the study and the biodegradebility of the test item can be evaluated on the basis of the results of the test because the difference could be considered not to be caused by mishandling andlor malfhction of the instruments, but by characteristics of the test item. (Table1)

Key result

Parameter:

other: % degradation by BOD

Value:

55

Sampling time:

28 d

Table 1:

 

		Value in this test	Value of criterion
Difference between extremes of replicate values of percentage biodegradation in test solution (sludge + test item) on day 28	BOD	24%	<20%
	Test item	7%
Percentage biodegradation by BOD in test solution (sludge + sodium benzoate on day 14		91%	>=60%
Percentage biodegradation by BOD in test solution (sludge +test item + sodium benzoate) on Day 14		37%	>=25%
Biochemical oxygen demand in test solution (control blank) on Day 28		25 and 27mg/L	<=60 mg/L

Validity criteria fulfilled:

no

Remarks:

but no impacts on quality and integrity of the study

Interpretation of results:

inherently biodegradable, not fulfilling specific criteria

Conclusions:

The averages of percentage biodegradation were 55% by BOD and 77% by GC. In addition, growth of the sludge was observed at the end of the incubation.
The test item underwent biodegradation under the test conditions of this study. According to OECD test guideline 301F, the pass level for ready biodegradability is 60% biodegradation by BOD on Day 28 and in the 10-day window. In the study, the percentage
biodegradation by BOD on Day 28 in the test vessel No. 1 (43%) and that in the loday window in the test vessels Nos. 1 and 2 (34% and 50%) did not reach the pass level although that by BOD in the test vessel No. 2 on Day 28 (67%) reached the pass level. The GC analysis showed that all of the test item components underwent primary degradation and 6 components of the 14 components disappeared completely. In addition , 11 degradation products were detected by LC-MS. Therefore, it was concluded that the test item was considered not a ready biodegradable substance although it seemed to have inherent biodegradability because the percentage biodegradation by BOD was 67% in one of the test solutions and the BOD curves of the test solutions were rising on Day 28.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable, not fulfilling specific criteria

Type of water:

freshwater

Additional information

The substance is considered rapidly degradable in the environment as follows:

- Substance reached>70% biodegradation by GC examination.

- One of the test vessel almost reached 70% biodegradation on basis of BOD within 28 days. It is highly possible that the substance would reach >70% if the test was reconducted.

- CLP paragraph 4.1.2.9.3 "Many degradation data are available in the form of degradation half-lives and these can be used in defining rapid degradation provided that ultimate biodegradation of the substance, i.e. full mineralisation, is achieved. Primary biodegradation does not normally suffice in the assessment of rapid degradability unless it can be demonstrated that the degradation products do not fulfil the criteria for classification as hazardous to the aquatic environment."

Several degradants were identified and 60.2% of the components achieved complete mineralisation within the scope of the test, with other major degradants showing significant onwards degradation.

The available information seems to indicate that the substance would be considered to be "rapidly degradable", provisionally as being inherently biodegradable. With the absence of an actual inherent biodegradation test, it is not possible to state definitively that this is the case, however, there is significant evidence from the OECD 301F study that mineralisation within the environment would occur under relevant conditions.