1,2,4-Benzenetricarboxylic acid, mixed lauryl and octyl triesters

Biodegradation in water and sediment: simulation tests

Administrative data

Endpoint:

biodegradation in water: sediment simulation testing

Type of information:

other: Literature weight of evidence

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Data source

Reference

Reference 1

Reference Type:

publication

Title:

High Production Volume (HPV) Chemical Challenge Program Test Plan for the Trimellitate Category

Author:

Exxon Biomedical Sciences.

Year:

2001

Bibliographic source:

Submitted to the US EPA on 13 Dec. 2001.

Report date:

2001

Reference 2

Reference Type:

publication

Title:

Measurement of Sorption Coefficients of Organic Chemicals and Their Use in Environmental Fate Analysis, Test Protocols for Environmental Fate and Movement of Toxicants, proceedings 94th Annual Meeting

Author:

McCall, P.J., Laskowski, D.A., Swann, R.L. and Dishburger, H.J.

Year:

1980

Bibliographic source:

94th Annual Meeting, Association of Official Analytical Chemists, Washington, D.C., October 21-22, 1980, pp. 89-109.

Report date:

1980

Reference 3

Reference Type:

publication

Title:

Biodegradation of mono-alkyl phthalate esters in natural sediments.

Author:

Otton, V., Sura, S., Blair, J., Ikonomou, M. and Gobas, F.

Year:

2008

Bibliographic source:

Chemosphere 71 (11): 2011-2016

Materials and methods

Test guideline

Qualifier:

no guideline required

Principles of method if other than guideline:

Literature data weight of evidence review

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

tris(mixed dodecyl and octyl)benzene-1,2,4-tricarboxylate

EC Number:

700-342-7

Cas Number:

1163775-81-2

Molecular formula:

C14H47O6 to C18H55O6

IUPAC Name:

tris(mixed dodecyl and octyl)benzene-1,2,4-tricarboxylate

Constituent 2

Reference substance name:

1,2,4-Benzenetricarboylic acid, mixed dodecyl and octyl triesters

IUPAC Name:

1,2,4-Benzenetricarboylic acid, mixed dodecyl and octyl triesters

Constituent 3

Reference substance name:

Linplast 812 TM

IUPAC Name:

Linplast 812 TM

Details on test material:

Smiles notation (if other than submission substance): O=C(c1ccc(cc1C(=O)OCCCCCCCC)C(=O)OCCCCCCCC)OCCCCCCCCCCCC

Study design

Inoculum or test system:

not specified

Results and discussion

Half-life of parent compound / 50% disappearance time (DT50)

Remarks on result:

not measured/tested

Transformation products:

not measured

Applicant's summary and conclusion

Conclusions:

Conclusion  The data requirement for sediment biodegradation is waived based on the weight of evidence supporting the conclusion that, while pathways exist for the degradation of 1,2,4-Benzenetricarboxylic acid, mixed decyl and octyl triesters, the degradation of substance will be limited due to limited bioavailability.  

Executive summary:

Sediment biodegradation studies are not needed due to the fact that, while microbial pathways exist for the degradation of 1,2,4-Benzenetricarboxylic acid, mixed dodecyl and octyl triesters, the degradation of substance will be limited due to limited bioavailability.  Biodegradation Pathway  A microbial pathway (ester hydrolysis) does exist in nature for degradation of esters (Otton et al., 2008).  According to the trimellitate category test plan for the US EPAs HPV Chemical Challenge Program, the degradation of the trimellitates is expected to precede through the step-wise hydrolysis of the ester groups to free alcohols and mellitic acid (ExxonMobil Biomedical Sciences, 2001). Further, the test plan states that these metabolites are known to rapidly degrade and not persist.  Evidence of the biodegradation potential for  1,2,4-Benzenetricarboxylic acid, mixed dodecyl and octyl triesters, can be observed with the results from two OECD 301B ready biodegradability studies of the structural related substance 1,2,4-Benzenetricarboxylic acid, mixed decyl and octyl triesters .  In both studies there is an extended time lag (14 to 24 days) before biodegradation begins to occur.  However, once biodegradation is initiated, the substance is significantly degraded (>70%) within 48 days.  Limited Bioavailablity  1,2,4-Benzenetricarboxylic acid, mixed dodecyl and octyl triesters is an extremely hydrophobic substance that will have limited bioavailability to microorganisms living in soil.  The limited bioavailability of the substance will also limit the amount of biodegradation that can occur in the soil.  The measured log Koc value of the structural related substance 1,2,4-Benzenetricarboxylic acid, mixed dodecyl and octyl triesters was greater than 5.67 (the log Koc of the most hydrophobic standard).  Using the KOCWIN Program v2.00 embedded in the US EPAs EPI Suite software (EPIWEB 4.0), the calculated log Koc values for 1,2,4-Benzenetricarboxylic acid, mixed dodecyl and octyl triesters ranged from 8.4 (estimated from the log Pow) to 8.98 (estimated from MCI).  The equivalent calculated Koc values were 260600000 L/kg to 9470000000 L/kg.  Based on these results, 1,2,4-Benzenetricarboxylic acid, mixed decyl and octyl triesters is expected to be immobile in soil (Koc >5000, classification according to McCall et al., 1980).  Conclusion  The data requirement for sediment biodegradation is waived based on the weight of evidence supporting the conclusion that, while pathways exist for the degradation of 1,2,4-Benzenetricarboxylic acid, mixed decyl and octyl triesters, the degradation of substance will be limited due to limited bioavailability.