Dichloromethylbenzene

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1995 or before

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Justification for type of information:

The study was performed by the MITI, Japan and peer reviewed for NITE, Japan. The principles of the OECD Guideline 305 seem to have been followed.
The substance described in this dossier is an isomeric mixture of five position isomers of dichlorotoluene. The similarities concerning chemical structure and key intrinsic properties such as log Kow and water solubility lead to the assumption that the other intrinsic values and values for ecotoxicological endpoints will also be very similar for the individual isomers and the mixture of isomers and that therefore results obtained with isomers can be useful for the assessment of the mixture.

Reason / purpose for cross-reference:

reference to other study

Principles of method if other than guideline:

Not reported, but the principles of the OECD Guideline 305 seem to have been followed.

GLP compliance:

no

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
None

Details on sampling:

Not reported

Vehicle:

not specified

Details on preparation of test solutions, spiked fish food or sediment:

reported to be of "improved type for a volatile substance"

Test organisms (species):

Cyprinus carpio

Details on test organisms:

Not reported

Route of exposure:

aqueous

Test type:

not specified

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

8 wk

Hardness:

Not reported

Test temperature:

Not reported

pH:

Not reported

Dissolved oxygen:

Not reported

TOC:

Not reported

Salinity:

Not applicable

Details on test conditions:

Not reported

Nominal and measured concentrations:

2 and 20 µg/L (not specified if nominal or measured)

Reference substance (positive control):

not specified

Details on estimation of bioconcentration:

Not reported

Lipid content:

4.4 %

Type:

BCF

Value:

> 639 - < 939

Remarks on result:

other: Conc.in environment / dose:2 µg/L

Type:

BCF

Value:

> 606 - < 858

Remarks on result:

other: Conc.in environment / dose:20 µg/L

Details on kinetic parameters:

Not reported

Metabolites:

Not reported

Results with reference substance (positive control):

Not reported

Details on results:

Not reported

Reported statistics:

Not reported

Further information not provided

Validity criteria fulfilled:

not specified

Conclusions:

The BCF for 2,4 - dichlorotoluene was determined experimentally on carp (Cyprinus carpio) with a lipid content of 4.4%. The BCF was found to be 639 -939 at a concentration f 2 µg/L and 606 - 858 at 20 µg/L.

Executive summary:

The BCF for 2,4-dichlorotoluene was determined experimentally by MITI on carp (Cyprinus carpio) with a lipid content of 4.4%. The BCF was found to be 639 -939 at a concentration of 2 µg/L and 606 - 858 at 20 µg/L.

Reference: database NITE, <=1995

Reference 2

Endpoint:

bioaccumulation: aquatic / sediment

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

weight of evidence

Study period:

Not reported

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Justification for type of information:

Calculation, peer reviewed by HSDB and therefore only summarised data available.
The substance described in this dossier is an isomeric mixture of five position isomers of dichlorotoluene. The similarities concerning chemical structure and key intrinsic properties such as log Kow and water solubility lead to the assumption that the other intrinsic values and values for ecotoxicological endpoints will also be very similar for the individual isomers and the mixture of isomers and that therefore results obtained with isomers can be useful for the assessment of the mixture.

Reason / purpose for cross-reference:

reference to other study

Principles of method if other than guideline:

Calculation from a measured log Kow according to Hansch and Leo (1985, Medchem Project Claremont CA: Pomona College as cited in HSDB) and a regression-derived equation by Lyman Handbook of Chemical Property Estimation methods (1990, Amer. Chem. Soc. 995-4, 5-10) and Veith et al. (1980, An Evaluation of Using Partition Coefficients and Water Solubility to Estimate Bioconcentration Factors for Organic Chemicals in Fish, J. Fish. Res. Board Can. as cited in Lyman Handbook)

GLP compliance:

no

Specific details on test material used for the study:

Not reported

Details on sampling:

Not applicable, calculation

Vehicle:

not specified

Details on preparation of test solutions, spiked fish food or sediment:

Not applicable, calculation

Test organisms (species):

no data

Details on test organisms:

No data

Hardness:

Not applicable, calculation

Test temperature:

Not applicable, calculation

pH:

Not applicable, calculation

Dissolved oxygen:

Not applicable, calculation

TOC:

Not applicable, calculation

Salinity:

Not applicable

Details on test conditions:

Not applicable, calculation

Nominal and measured concentrations:

Not applicable, calculation

Reference substance (positive control):

not required

Details on estimation of bioconcentration:

The equation given by Lymann (1990) is: log BCF = 0.76 log Kow - 0.23 and was referenced to be from Veith et al. (1980, see the references in "principle of method if other than guideline")

Type:

BCF

Value:

1 000 dimensionless

Basis:

other: measured log Kow of 4.24

Details on kinetic parameters:

Not applicable, calculation

Metabolites:

Not applicable, calculation

Results with reference substance (positive control):

Not applicable, calculation

Details on results:

Not reported

Reported statistics:

Not reported

Other information not reported

Validity criteria fulfilled:

not specified

Conclusions:

The BCF value was calculated for 2,4-dichlorotoluene using a measured log kow of 4.24 according to Hansch and Leo (1985) and a regression-based equation by Lyman (1990) / Veith et al (1980, all references given in "principle of method if other than guideline")

Executive summary:

The BCF value was calculated for 2,4-dichlorotoluene using a measured log kow of 4.24 according to Hansch and Leo (1985) and a regression-based equation by Lyman (1990) / Veith et al (1980, all references given in "principle of method if other than guideline") to be 1000.

Reference: HSDB, 2009

Reference 3

Endpoint:

bioaccumulation in aquatic species, other

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Study period:

2010

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with limited documentation / justification

Justification for type of information:

Generally accepted calculation method, based on experimental log kow.
The substance described in this dossier is an isomeric mixture of five position isomers of dichlorotoluene. The similarities concerning chemical structure and key intrinsic properties such as log Kow and water solubility lead to the assumption that the other intrinsic values and values for ecotoxicological endpoints will also be very similar for the individual isomers and the mixture of isomers and that therefore results obtained with isomers can be useful for the assessment of the mixture.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Principles of method if other than guideline:

The Bioconcentration factor BCF was calculated with the programme BCFBAF v.3.00 by using the experimental result of log Kow = 4.2 - 4.3 obtained with the HPLC method according to OECD Guideline 117 (Neuland, 2010).

Details on estimation of bioconcentration:

Estimation software: BCFBAF v.3.00
Equation used: log BCF = 0.6598 log Kow - 0.333

Type:

BCF

Value:

274.3 dimensionless

Remarks on result:

other: based on log Kow = 4.2

Type:

BCF

Value:

319.3 dimensionless

Remarks on result:

other: based on log Kow = 4.3

Further information not provided

Validity criteria fulfilled:

not applicable

Conclusions:

The BCF was calculated to be 274.3 - 319.3.

Executive summary:

The bioconcentration factor BCF was calculated to be 274.3 - 319.3. The programme BCFBAF v.3.00 and the experimental result of log Kow = 4.2 - 4.3 obtained with the HPLC method according to OECD Guideline 117 (Neuland, 2010) were used.

Reference: Keller, 2010

Description of key information

For one of the main isomers, 2,4-DCT, in a study in fish, the BCF was determined to be 606 – 939. (Reference: Database NITE, <=1995)
For the risk assessment, the value of 939 is chosen for the DCT-mixture. It is concluded that DCT mixture has a moderate bioaccumulation potential. 

Key value for chemical safety assessment

BCF (aquatic species):

939 dimensionless

Additional information

Weight of evidence:

The BCF for 2,4-dichlorotoluene was determined experimentally by MITI on carp (Cyprinus carpio) with a lipid content of 4.4%. The BCF was found to be 639 - 939 at a concentration of 2 µg/L and 606 - 858 at 20 µg/L. The principles of the OECD Guideline 305 seem to have been followed.

Reference: Database NITE, <=1995

The bioconcentration factor was calculated for dichloromethylbenzene mixture to be 274.3 - 319.3. The programme BCFBAF v.3.00 and the experimental result of log kow = 4.2 - 4.3 obtained with the HPLC method according to OECD Guideline 117 (Neuland, 2010) were used.

Reference: Keller, 2010

The BCF value was calculated for 2,4-dichlorotoluene to be 1000 by using a regression-based equation by Lyman (1990) / Veith et al (1980) based on a measured log kow of 4.24 according to Hansch and Leo (1985) .

Reference: Database HSDB, 2009

For the risk assessment, the experimentally determined value of 939 is chosen. It is concluded that DCT mixture has a moderate bioaccumulation potential.