Propylidynetrimethanol

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1990

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study, GLP

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test)

Deviations:

not specified

Principles of method if other than guideline:

The method was reported to be on the basis of EG-Guideline 79/831 EWG annex V; OECD Guideline 301 E: Modified OECD-Screening

GLP compliance:

yes

Oxygen conditions:

not specified

Inoculum or test system:

activated sludge, industrial, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): STP for Laboratories, Wupperverband
- Concentration of inoculum: 0.5 mL/900mL.

Duration of test (contact time):

28 d

Initial conc.:

19 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Test temperature: 22+/-2°C
- Continuous darkness: yes

SAMPLING
- Sampling frequency: DOC-measurements were made on day 0, 7, 14, 21, 27 and 28.

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes

CALCULATION
Percentage DOC-removal = [DOC (start of the test) - DOC (end of the test)/DOC (start of the test)] x 100

Reference substance:

aniline

Parameter:

% degradation (DOC removal)

Value:

6

Sampling time:

28 d

Details on results:

Details were not provided

Results with reference substance:

DOC removal of reference substance (in %): 100 after 28 days.

Time [h]	DOC Inoculum blank	DOC test substance [mg/L]	DOCcorr.^* test substance [mg/L]	DOC removal   [%]
o	2	19	17	0
7	2	19	17	0
14	2	18	16	6
21	2	20	18	0
27	2	19	17	0
28	2	18	16	6

DOC_corr.^*= value for test substance - value for inoculum

Validity criteria fulfilled:

yes

Remarks:

Reference substance degraded by 100% within 28 days

Interpretation of results:

other: not readily biodegradable

Executive summary:

A 28-d Modified Screening Test was performed on the basis of the OECD guideline 301E with predominantly domestic sewage.

6% degradation was observed within 14 and 28 days.

Trimethylolpropane is not readily biodegradable.

Reference: Müller & Caspers, 1990

Description of key information

Trimethylolpropane was shown not to be readily biodegradable, but fulfilled the criterion for inherent, ultimative biodegradability (70% degradability within 7 days).

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable, fulfilling specific criteria

Type of water:

freshwater

Additional information

READY BIODEGRADABILITY

Key study:

A 28-d Modified Screening Test was performed on the basis of the OECD guideline 301E with predominantly domestic sewage. 6% degradation was observed within 14 and 28 days. Trimethylolpropane is not readily biodegradable.

Reference: Müller & Caspers, 1990

Supporting studies:

A 14-d Modified MITI Test (I) was performed on the basis of the OECD guideline 301C with activated sludge. 4% degradation was observed within 14 days on the basis of O2 consumption, 3 % when estimated by test material analysis by HPLC. Trimethylolpropane is not readily biodegradable.

Reference: MITI; <= 1994

The ready biodegradability of trimethylopropane was tested in a 14 -d MITI (I)-Test following a Japanese guideline, which corresponds to OECD 301C. The test substance was investigated at a concentration of 100 mg/L. 30 mg/L of activated sludge was used as inoculum. Degradation of trimethylopropane was recorded over a period of 14 days by analyzing BOD, TOC and the active substance. Trimethylopropane was degraded to 1.7 % (based on BOD) and 3 % (from test material analysis by GC) and is therefore considered not readily biodegradable.

Reference: CITI Japan, 1992

Further studies:

A 20-d Closed Bottle Test was performed with trimethylolpropan at a concentration of 2.4 mg/L.

0% degradation was observed within 5, 10 and 20 days.Trimethylolpropane is not readily biodegradable. As only a short abstract is available, the reliability is not assignable.

Reference: Müller & Caspers, 1973

A 20-d Closed Bottle Test was performed with trimethylolpropan at concentrations of 2.4, 8, 24 and 80 mg/L.

0% degradation was observed within 20 days.Trimethylolpropane is not readily biodegradable. As the used sludge population was adapted and the available information is too scarce, the study is not reliable.

Reference: Anonymous (Bayer), 1973

INHERENT BIODEGRADABILITY

Key study:

The inherent biodegradability of trimethylolpropane was tested in a 28-d- Zahn-Wellens test following the OECD Guideline 302B (draft from 1989) and GLP requirements. With an initial test substance concentration of 100 mg/L and an activated sludge concentration of 0.4 g dry weight/L 100% degradability of trimethylolpropane was determined by DOC-removal. 100% of the reference substance aniline degraded within the test period.

Trimethylolpropane was shown to be 100% inherently biodegradable after 28 days and fulfilled the criterion for inherent, ultimative biodegradability (70% degradability within 7 days).

Reference: Caspers & Müller, 1992

Supporting studies:

The inherent biodegradability was tested in a 17 d Zahn-Wellens-Test following the OECD Guideline 302B. A 0.1% aquatic solution of the test substance was exposed to activated sludge. 95% degradation was measured on day 15 and 98% on day 17 by DOC removal. The substance is inherently biodegradable.

As only a citation of a guideline test is available, the reliabiliy cannot be assigned.

Reference: BASF, Institute Kuhlmann, 1988

FURTHER STUDIES (BOD5, BOD10 and BOD15)

The BOD5 was estimated in the study to be > 5 mg O2/mg trimethylolpropane. For the dossier compilation, a ThOD of 1.908 mg/L was calculated according the formula given in OECD-Guideline 301, Annex IV. From these results, a degradation rate from BOD x 100/ThOD may not be calculated.

As only a short abstract is available, the reliability may not be assigned.

Reference: BASF, Institute Kuhlmann, 1988

The BOD5, BOD10 and BOD15 was estimated in the study to be 0.033, 0.269 and 0.428 mg O2/mg trimethylolpropane.

For the dossier compilation, a ThOD of 1.908 mg/L was calculated according the formula given in OECD-Guideline 301, Annex IV.

From these results, the following degradation rates are calculated: ca. 1.7 % on day 5, ca. 14.1 % on day 10 and ca. 22.4 % on day 15.

As only a short abstract is available, the reliability cannot be assigned.

Reference: Walton & Davis, 1980