Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1991-05-22 to 1991-06-21
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
Study conducted to an appropriate guideline under GLP, measured endpoint (CO2 production) provides unambiguous evidence of mineralisation.
Reason / purpose:
read-across: supporting information
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Version / remarks:
(performed according to the original 1984 version of the guideline ("Modified Sturm Test"), current at the time of testing)
Deviations:
no
Remarks:
(The current OECD 301B (1992) recommends a single concentration and has introduced the concept of the 10-day window, but the test procedure is fundamentally the same as the 1984 version).
GLP compliance:
yes (incl. certificate)
Specific details on test material used for the study:
Trimellitic anhydride
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): Activated sludge (KA Frankfurt/Main - Niederrad)
- Preparation of inoculum for exposure: Washed twice and resuspended in mineral salts medium, aerated for 4 hours, homogenized, settled and filtered through coarse filter paper. The filtrate was used as the test inoculum added at a rate of 1% of the final test mixture volumes.
Duration of test (contact time):
28 d
Initial conc.:
10.19 mg/L
Based on:
test mat.
Initial conc.:
20.29 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation:
CO2 evolution
Reference substance:
benzoic acid, sodium salt
Key result
Parameter:
% degradation (CO2 evolution)
Value:
98.7
Sampling time:
28 d
Remarks on result:
other: at ca. 10 mg TMA/L. 65.3% degradation (first measurement >60%) was recorded on day 5.
Key result
Parameter:
% degradation (CO2 evolution)
Value:
77.4
Sampling time:
28 d
Remarks on result:
other: at ca. 20 mg TMA/L. 66.6% degradation (first measurement >60%) was recorded on day 7.
Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
Trimellitic anhydride is readily biodegradable.
Executive summary:

Trimellitic anhydride (TMA, source substance) was tested for ready biodegradability according to the 1984 OECD 301B (Sturm Test) procedure, at concentrations of approximately 10 and 20 mg/L. The measured CO2 yield from trimellitic anhydride exceeded 60% of theoretical at both concentrations and the 60% threshold was crossed within the 10 -day window, i.e. within 10 days of CO2 production reaching 10% of theoretical. Trimellitic anhydride is therefore considered to be readily biodegradable.

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
The read across justification is described in the document attached in section 13.
Reason / purpose:
read-across source
Specific details on test material used for the study:
Trimellitic anhydride-chloride
Key result
Parameter:
% degradation (CO2 evolution)
Value:
98.7
Sampling time:
28 d
Remarks on result:
other: at ca. 10 mg TMA/L. 65.3% degradation (first measurement >60%) was recorded on day 5.
Key result
Parameter:
% degradation (CO2 evolution)
Value:
77.4
Sampling time:
28 d
Remarks on result:
other: at ca. 20 mg TMA/L. 66.6% degradation (first measurement >60%) was recorded on day 7.
Validity criteria fulfilled:
not applicable
Interpretation of results:
readily biodegradable
Conclusions:
According to the results of the biodegradation study performed on trimellitic anhydride (TMA) : source substance and analogue of the target substance trimellitic anhydride mono-chloride (TMAC), it can be expected that the target substance will be readily biodegradable like the source substance regarding their close structural similarity.
Executive summary:

No biodegradation test is available on trimellitic anhydride mono-chloride (TMAC, target substance), but one study is available on its analogue trimellitic anhydride (TMA, source substance). They have a close structural similarity.

In Battelle Europe's study (Lebertz, 1991) on trimellitic anhydride (source substance), the ready biodegradability was tested according to the 1984 OECD 301B (Sturm Test) procedure, at concentrations of approximately 10 and 20 mg/L. The measured CO2 yield from trimellitic anhydride exceeded 60% of theoretical at both concentrations and the 60% threshold was crossed within the 10-day window, i.e. within 10 days of CO2 production reaching 10% of theoretical.

According to this study, the conclusion is that the source and target substances should be regarded as readily biodegradable.

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study.
Reason / purpose:
read-across: supporting information
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))
Principles of method if other than guideline:
Japanese MITI I test, adopted by OECD as Guideline 301C in 1984.
Ultimate biodegradability was determined during a 28-day incubation by measuring oxygen consumption and expressing measured biochemical oxygen demand (BOD) as a percentage of theoretical. Confirmatory measurements were made by analyses for total organic carbon (TOC).
GLP compliance:
not specified
Specific details on test material used for the study:
Trimellitic anhydride
Oxygen conditions:
aerobic
Inoculum or test system:
mixture of sewage, soil and natural water
Duration of test (contact time):
28 d
Initial conc.:
100 mg/L
Based on:
test mat.
Key result
Parameter:
% degradation (O2 consumption)
Value:
96
Sampling time:
28 d
Parameter:
% degradation (TOC removal)
Value:
99
Sampling time:
28 d
Validity criteria fulfilled:
not specified
Interpretation of results:
readily biodegradable
Conclusions:
Trimellitic anhydride (TMA) is readily biodegradable.
Executive summary:

Trimellitic anhydride (TMA), applied at 100 mg/L, was tested for biodegradability by the Chemicals Inspection and Testing Institute (CITI) of Japan to fulfil the requirements of the Japanese Chemical Substances Control Law. A composite inoculum (applied at 30 mg suspended solids/L) originating from ten specified locations around Japan, not deliberately adapted to the test substance, fed with peptone and glucose prior to use and renewed at regular intervals (see OECD Guideline 301C 1984 and 1992 for details) was employed as standard practice at CITI for these investigations. An automated respirometer was used to make continuous measurements of biochemical oxygen demand (BOD) and recorded BOD was compared to a theoretical oxygen uptake calculated the complete mineralisation of TMA to its terminal oxidation products. This comparison provides a measure of ultimate biodegradation. Measured BOD expressed as a percentage of theoretical oxygen demand ( %ThOD) was 96% within 14 days in this study. Confirmatory indications are provided by analyses of total organic carbon (TOC) - this technique showed 99% removal of organic carbon from the test system and is consistent with the figure of 96% ultimate biodegradation based on oxygen uptake.

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
supporting study
Justification for type of information:
The justification of the read across is described in the document attached in section 13.
Reason / purpose:
read-across source
Duration of test (contact time):
28 d
Key result
Parameter:
% degradation (O2 consumption)
Value:
96
Sampling time:
28 d
Remarks on result:
other: at 100 mg/L of TMA
Parameter:
% degradation (TOC removal)
Value:
99
Sampling time:
28 d
Remarks on result:
other: at 100 mg/L of TMA
Validity criteria fulfilled:
not applicable
Interpretation of results:
readily biodegradable
Conclusions:
According to the results of the biodegradation study performed on trimellitic anhydride (TMA,source substance), analogue of the target substance trimellitic anhydride chloride (TMAC), it can be expectecd that the target substance will be readily biodegradable, like the source substance, regarding the close structural similarity.
Executive summary:

No biodegradation test is available on trimellitic anhydride mono-chloride (target substance), but one study is available on its analogue trimellitic anhydride (source substance). They have a close structural similarity.

Trimellitic anhydride (TMA), applied at 100 mg/L, was tested for biodegradability by the Chemicals Inspection and Testing Institute (CITI) of Japan to fulfil the requirements of the Japanese Chemical Substances Control Law. A composite inoculum (applied at 30 mg suspended solids/L) originating from ten specified locations around Japan, not deliberately adapted to the test substance, fed with peptone and glucose prior to use and renewed at regular intervals (see OECD Guideline 301C 1984 and 1992 for details) was employed as standard practice at CITI for these investigations. An automated respirometer was used to make continuous measurements of biochemical oxygen demand (BOD) and recorded BOD was compared to a theoretical oxygen uptake calculated the complete mineralisation of TMA to its terminal oxidation products. This comparison provides a measure of ultimate biodegradation. Measured BOD expressed as a percentage of theoretical oxygen demand ( %ThOD) was 96% within 14 days in this study. Confirmatory indications are provided by analyses of total organic carbon (TOC) - this technique showed 99% removal of organic carbon from the test system and is consistent with the figure of 96% ultimate biodegradation based on oxygen uptake.

According to this study, the conclusion is that the source and target substances should be regarded as readily biodegradable.

Description of key information

One experimental GLP study (Lebertz, 1991) considered valid without restrictions performed on the source substance trimellitic anhydride (TMA) at two concentrations; one validity 2 experimental study performed on the source substance (CITI 1988) and one disregarded study (technically invalid as did no meet the validity criteria) performed on the registered substance (TMAC) are available.

Based on these results, the target substance, trimellitic anhydride mono chloride (TMAC), is considered as readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable

Additional information

One of the three available studies was performed on the registered substance trimellitic anhydride mono-chloride (TMAC,target substance), while the two others were performed in its analogue trimellitic anhydride (TMA,source substance).

The first disregarded study was performed on the registered substance trimellitic anhydride mono-chloride (TMAC), according to a test similar to MITI test.

The degradation of the substance after 28 days was found to be -11% while the degradation of the reference substance (Aniline) was 65% after 7 days of exposure. The blank inoculum control (containing only test medium) had greater oxygen consumption than the test substance throughout the study period. No toxicity test (with both test substance and reference substance) was performed and no sufficient data are available on the inoculum and flasks preparation, thus it is not possible to find the cause of these results. Moreover, no specific chemical analysis was performed to assess primary degradation while it is mandatory for the MITI test. Furthermore, one of the validity criteria is not fulfilled as the difference between extremes degradation values of replicates at the end of the test were more than 20%.

Thus the study is considered as not reliable and was disregarded.

Trimellitic anhydride (TMA) was tested for ready biodegradability by two respirometric methods where the degradation "pass" level that conventionally represents complete mineralisation is 60%:

In a GLP-compliant (Klimisch 1) study based on CO2 evolution (Lebertz, 1991), 98.7% and 77.4% degradation occurred within 28 days at concentrations of 10 and 20 mg TMA/L, respectively and the 60% pass level was exceeded within 7 days. Recovery of CO2 provides a direct and unambiguous indication of the mineralisation of the test substance.

Confirmatory data (Klimisch 2) are provided by a study performed in fulfilment of the requirements of the Chemical Substances Control Law of Japan (CITI, 1988). In this study, 96% degradation of TMA dosed at 100 mg/L was recorded in 28 days by the principal indicator of mineralisation based on oxygen uptake measurements, and further measurements performed in this study indicated 99% ultimate degradation based on TOC removal (the "pass" criterion that applies here is 70%).

These results show that trimellitic anhydride (rapidly hydrolysed into trimellitic acid under test conditions) is readily biodegradable.

Due to close structural similarity between trimellitic anhydride and trimellitic anhydride mono-chloride (target substance), trimellitic anhydride mono-chloride can be considered as readily biodegradable.