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Environmental fate & pathways

Distribution modelling

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Administrative data

Endpoint:
distribution modelling
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)

Data source

Reference
Reference Type:
other: SIDS initial assessment report
Title:
SIDS initial assessment report for SIAM15 tetrahydromethyl -1,3-isobenzofuranedione
Author:
Katsuo K.
Year:
2002
Bibliographic source:
SIDS initial assessment report

Materials and methods

Model:
calculation according to Mackay, Level III
Calculation programme:
Mackay, level III
Release year:
2 001
Media:
air - biota - sediment(s) - soil - water

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Molecular formula (if other than submission substance): C9 H10 O3
- Molecular weight (if other than submission substance): 166.18
- Smiles notation (if other than submission substance): O=C(OC(=O)C1CC=C(C2)C)C12
- InChl (if other than submission substance): 1/C9H10O3/c1-5-2-3-6-7(4-5)9(11)12-8(6)10/h2,6-7H,3-4H2,1H3
- Structural formula attached as image file (if other than submission substance): see Fig. (11070-44-3 structure.png)

Study design

Test substance input data:
MTHPA dissociation substance
- Molar mass: 184.19
- Data temperature: 25 degree C
- Water solubility: 10500 g/m3
- Vapour pressure:1.75E-3
- log Pow: 1.28

- Reaction half-life estimates for
- Air: 10.04
- Water: 240000
- Soil: 240000
- Sediment: 240000
Environmental properties:
to water

Results and discussion

Percent distribution in media

Air (%):
0
Water (%):
99.5
Soil (%):
0
Sediment (%):
0.5
Susp. sediment (%):
0
Biota (%):
0
Aerosol (%):
0

Any other information on results incl. tables

Tetrahydromethyl-1,3-isobenzofuranedione is considered to be hydrolyzed to 3-methyl-4(or 3)-cyclohexene-1,2-dicarboxylic acid and/or 4-cyclohexene-1,2-dicarboxylic acid in environment. So, the potential environmental distribution of 4-methyl-4-cyclohexene-1,2-dicarboxylic acid (one of the hydrolysate of tetrahydromethyl-1,3-isobenzofuranedion) obtained from a generic level III fugacity model is shown below:

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Compartment  Release      Release       Release
            100% to air  100% to water 100% to soil

-------------------------------------------------------------------------

Air            0.0 %        0.0 %         0.0 %
Water        31.6 %       99.5 %        26.9 %
Soil          68.3 %        0.0 %        72.9 %
Sediment      0.2 %        0.5 %         0.1 %

For details on results see attachment.

Applicant's summary and conclusion

Executive summary:

It is confirmed that tetrahydromethyl-1,3-isobenzofuranedione hydrolyzes to the corresponding di-carboxylic acid in water.

Therefore, this substance is considered to be hydrolyzed to the corresponding di-carboxylic acids in the environment. These hydrolysis products are considered to be stable in the water phase. The potential environmental distribution of 4-methyl-4-cyclohexene-1,2-dicarboxylic acid (one of the representative hydrolysis product of tetrahydromethyl-1, 3-isobenzofuranedion) is obtained from a generic fugacity model level III relevant for the following figures:

-------------------------------------------------------------------------

Compartment  Release      Release       Release
            100% to air  100% to water 100% to soil

-------------------------------------------------------------------------

Air            0.0 %        0.0 %         0.0 %
Water        31.6 %       99.5 %        26.9 %
Soil          68.3 %        0.0 %        72.9 %
Sediment      0.2 %        0.5 %         0.1 %

For details on results see attachment.