4-sec-butyl-2,6-di-tert-butylphenol

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

3 August 2005 - 14 February 2006

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

abstract

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: “Biodegradation test of a chemical substance using a microorganism etc.” provided in “the Notice on the Test Method Concerning New Chemical Substances"

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4-sec-butyl-2,6-di-tert-butylphenol

EC Number:

241-533-0

EC Name:

4-sec-butyl-2,6-di-tert-butylphenol

Cas Number:

17540-75-9

Molecular formula:

C18H30O

IUPAC Name:

4-(butan-2-yl)-2,6-di-tert-butylphenol

Test material form:

not specified

Details on test material:

- Physical appearance: not indicated
- Storage conditions: not indicated

Study design

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Concentration of activated sludge: 30 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 1

Parameter followed for biodegradation estimation:

O2 consumption

Remarks:

BOD

Parameter followed for biodegradation estimation 2

Parameter followed for biodegradation estimation:

test mat. analysis

Remarks:

HPLC

Details on study design:

Test temperature: 25±1 °C

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

% Degradation 1

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Remarks on result:

other: % degradation for individual bottles were -1, -1 and -1%

Remarks:

Because the mean degradation was calculated as a negative value, the mean value was determined as 0

% Degradation 2

Key result

Parameter:

% degradation (test mat. analysis)

Value:

2

Sampling time:

28 d

Remarks on result:

other: % degradation for individual bottles were 3, 2 and 1%

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

Based on the results of a Modified MITI Test, performed according to OECD guideline 301C, 4-sec-Butyl-2,6-di-tert-butylphenol was determined to be not-readily biodegradable.

Executive summary:

A Modified MITI Test was performed, according to OECD guideline 301C and GLP principles, to assess the biodegradability of 4-sec-Butyl-2,6-di-tert-butylphenol. The O2 concumption of the test item (100 mg/L) was measured over a period of 28 days and the amount of remaining test material was analysed using HPLC. Activated sludge was used as inoculum at a concentration of 30 mg/L. Analine was included as the reference control. The biodegradation values were expressed based on the O2 consumption (BOD) and analysis of the test item (HPLC) and were 0% and 2%, respectively. Based on these results, 4-sec-Butyl-2,6-di-tert-butylphenol is determined to be not-readily biodegradable. Since unsufficient details were provided in the applicant's summary of the test report, the study cannot be fully assessed for its reliability and it is regarded as a K2 study (guideline study without detailed documentation).