2,3,5-trimethylhydroquinone

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:

19.05.2003 - 17.06.2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 A (Ready Biodegradability: DOC Die Away Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,3,5-trimethylhydroquinone

EC Number:

211-838-3

EC Name:

2,3,5-trimethylhydroquinone

Cas Number:

700-13-0

Molecular formula:

C9H12O2

IUPAC Name:

2,3,5-trimethylhydroquinone

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study report): 2,3,5-Trimethylhydrochinone
- Lot/batch No.: T5600/4703/04/25
- Analytical purity: >= 99.5 %;
water solubility: not indicated.

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

Concentration of sludge: 30 mg/I (dry substance)

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

20 mg/L

Based on:

DOC

Initial test substance concentration 2

Initial conc.:

29 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

DOC removal

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

Key result

Parameter:

% degradation (DOC removal)

Value:

ca. 65

Sampling time:

28 d

Details on results:

Kinetic of test substance (in %):
ca. 18 after 3 day(s)
ca. 32 after 7 day(s)
ca. 41 after 14 day(s)
ca. 52 after 21 day(s)
ca. 65 after 28 day(s)

BOD5 / COD results

Results with reference substance:

Kinetic of control substance (in %):
= 10 after 3 day(s)
= 96 after 5 day(s)
Degradation products: not measured

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

The reference sample biodegraded within 5 days to a degree of 96%. The difference of extremes of replicate values of the removal of the test chemical at the end of the test is less than 20%.

Interpretation of results:

not readily biodegradable

Conclusions:

Trimethylhydroquinone is not rapidly biodegradable as determined in a DOC Die-away test.

Executive summary:

As a criterion for the classification as rapidly biodegradable a DOC-elimination of 70% of the test item within a 10 day-window during a total test duration of 28 days is considered. The test samples of trimethylhydroquinone do not meet this criterion since only 65% DOC-elimination during the total test duration were attained. Hence, trimethylhydroquinone is classified as not rapidly biodegradable.