EQC Level I Modelling

EQC Level I modelling has been performed for the 22 phthalate esters listed in Table 1 for which physical-chemical properties have previously been estimated (Table 3). Level I EQC model results indicate that under equilibrium, steady state conditions, with no reaction, the vast majority of phthalates released will reside in soil, sediment or water with over 99% being distributed to these three media (Table 6). The low vapour pressures ensure that only small percentages partition to air. Phthalate esters with alkyl chains containing greater than five carbons partition almost exclusively to the organic carbon component of soil and sediment, whereas those with short alkyl chains (< 4 carbons), and hence lower hydropho-bicities, partition readily to water.

Table 6. Summary of results of Level I and II simulations using the EQC model

Phthalate

Level I distribution

Level II distribution

ester

Air

Water

Soil

Sediment

Persistence

Loss by reaction

(%)

(%)

(%)

(%)

(days)

(%)

DMP

0.2

96.3

3.5

0.1

8.4

80

DEP

0.4

75.8

23.3

0.5

9.9

81

DAP

0.4

46.0

52.4

1.2

-

-

DPP

0.4

30.4

67.7

1.5

-

-

DnBP

0.2

5.6

92.2

2.1

28

95

DIBP

0.2

5.6

92.2

2.1

-

-

DnPP

0.1

0.8

96.9

2.2

-

-

BBP

0.1

2.2

95.6

2.1

27

98

DHP

<0.1

0.1

97.6

2.2

-

-

DnHP

<0.1

0.1

97.6

2.2

-

-

DIHpP

<0.1

< 0.1

97.7

2.2

-

-

DnOP

<0.1

< 0.1

97.8

2.2

-

-

BOP

<0.1

0.3

97.5

2.2

-

-

610P

<0.1

< 0.1

97.8

2.2

-

-

DEHP

<0.1

< 0.1

97.8

2.2

34

100

DIOP

<0.1

< 0.1

97.8

2.2

-

-

DnNP

<0.1

< 0.1

97.8

2.2

-

-

DINP

<0.1

< 0.1

97.8

2.2

-

-

DnDP

< 0.1

< 0.1

97.8

2.2

-

-

DIDP

< 0.1

< 0.1

97.8

2.2

-

-

D711P

<0.1

< 0.1

97.8

2.2

-

-

DUP

< 0.1

< 0.1

97.8

2.2

-

-

DTDP

< 0.1

< 0.1

97.8

2.2

-

-

Continue reading here: EQC Level II Modelling

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