Registration Dossier

Administrative data

Endpoint:
adsorption / desorption, other
Type of information:
(Q)SAR
Adequacy of study:
key study
Study period:
Starting date: 19 December 2016 Completion date: 19 December 2016
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification
Justification for type of information:
No determination of the adsorption coefficient was possible by the HPLC screening method, using a procedure designed to be compatible with Method C19 Adsorption Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 121 of the OECD Guidelines for Testing of Chemicals, 22 January 2001. These methods are not valid for this class of substance.
In place of experimental data, estimates of the adsorption coefficients were obtained by calculations using Quantitative Structure Activity Relationships (QSAR’s), the details of which are provided in the Technical Guidance Document on Risk Assessment in support of Commission Directive 93/67/EEC on Risk Assessment for new notified substances, Commission Regulation (EC) No 1488/94 on Risk Assessment for existing substance and Directive 98/8/EC of the European Parliament and of the Council concerning the placing of biocidal products on the market, Part IV.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017
Report Date:
2017

Materials and methods

Test guideline
Qualifier:
no guideline required
Version / remarks:
Adsorption coefficient was obtained by calculation using Quantitative Structure Activity Relationships (QSAR’s). The details are provided in the Technical Guidance Document on Risk Assessment in support of Commission Directive 93/67/EEC on Risk Assessment for new notified substances, Commission Regulation (EC) No 1488/94 on Risk Assessment for existing substance and Directive 98/8/EC of the European Parliament and of the Council concerning the placing of biocidal products on the market, Part IV.
Principles of method if other than guideline:
Adsorption coefficient was obtained by calculation using Quantitative Structure Activity Relationships (QSAR’s). The details are provided in the Technical Guidance Document on Risk Assessment in support of Commission Directive 93/67/EEC on Risk Assessment for new notified substances, Commission Regulation (EC) No 1488/94 on Risk Assessment for existing substance and Directive 98/8/EC of the European Parliament and of the Council concerning the placing of biocidal products on the market, Part IV.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
liquid
Specific details on test material used for the study:
Information as provided by the Sponsor. The Certificate of Analysis provided by the Sponsor is presented as Annex 1 (Please see Attachment Section of this Summary).

Identification: X-19574
Appearance/Physical state: Amber colored viscous liquid
Batch: X-19574-00-00
Purity: 100% (UVCB)
Expiry date: 01 June 2017
Storage conditions: Room temperature, in the dark

Results and discussion

Adsorption coefficientopen allclose all
Key result
Type:
log Koc
Value:
ca. 2.51 dimensionless
Remarks on result:
other: This is for the Dibutylphosphorothioate component
Key result
Type:
log Koc
Value:
ca. 3.42 dimensionless
Remarks on result:
other: This is for the Amines, C16-18-(even numbered, saturated and unsaturated) alkyl component

Any other information on results incl. tables

Results

The adsorption coefficient (Koc) of the test item components are shown in the following table:

Table 2

Component

Adsorption coefficient

Log10Koc

Mobility class

Dibutylphosphorothioate

321

2.51

medium

C16 – C18 and C18 unsaturated alkyl amines*

2.62 x 10E3

3.42

slightly

* The adsorption coefficient of the C16 – C18 and C18 unsaturated alkyl amine was estimated to be 3.42. However, the guidance document cautioned that the adsorption coefficient of alkyl amines maybe systematically underestimated by the method by up to 1 to 2 log units. Therefore by application of this correction factor, an adsorption coefficient of approximately 2.6 x 10E4 to 2.6 x 10E5 (log10Koc 4.42 to 5.42) would be obtained, indicating that this species is immobile in soils.

Applicant's summary and conclusion

Conclusions:
Using a QSAR calculation, the adsorption coefficient (Koc) of the test item has been estimated to be as follows:

Table 3
Component Adsorption coefficient Log10 Koc
Dibutylphosphorothioate 321 2.51
C16 – C18 and C18 unsaturated alkyl amine 2.62 x 10E3 3.42

The adsorption coefficient for the dibutylphosphorothioate component was assessed to have medium mobility in soils.

The adsorption coefficient of the C16 – C18 and C18 unsaturated alkyl amine was estimated to be 3.42. However, the guidance document cautioned that the adsorption coefficient of alkyl amines maybe systematically underestimated by the method by up to 1 to 2 log units. Therefore by application of this correction factor, an adsorption coefficient of approximately 2.6 x 10E4 to 2.6 x 10E5 (log10 Koc 4.42 to 5.42) would be obtained, indicating that this species is immobile in soils.
Executive summary:

No determination of the adsorption coefficient was possible by the HPLC screening method, using a procedure designed to be compatible with Method C19 Adsorption Coefficient ofCommissionRegulation (EC) No 440/2008 of 30 May 2008 and Method 121 of the OECD Guidelines for Testing of Chemicals, 22 January 2001. These methods are not valid for this class of substance. 

In place of experimental data, estimates of the adsorption coefficients were obtained by calculations using Quantitative Structure Activity Relationships (QSAR’s), the details of which are provided in the Technical Guidance Document on Risk Assessment in support of Commission Directive 93/67/EEC on Risk Assessment for new notified substances, Commission Regulation (EC) No 1488/94 on Risk Assessment for existing substance and Directive 98/8/EC of the European Parliament and of the Council concerning the placing of biocidal products on the market, Part IV.

Conclusion

Using a QSAR calculation, the adsorption coefficient (Koc) of the test item has been estimated to be as follows:

Table 3

Component

Adsorption coefficient

Log10Koc

Dibutylphosphorothioate

321

2.51

C16 – C18 and C18 unsaturated alkyl amine

2.62 x 10E3

3.42

The adsorption coefficient for the dibutylphosphorothioate component was assessed to have medium mobility in soils. 

The adsorption coefficient of the C16 – C18 and C18 unsaturated alkyl amine was estimated to be 3.42. However, the guidance document cautioned that the adsorption coefficient of alkyl amines maybe systematically underestimated by the method by up to 1 to 2 log units. Therefore by application of this correction factor, an adsorption coefficient of approximately 2.6 x 10E4 to 2.6 x 10E5 (log10Koc 4.42 to 5.42) would be obtained, indicating that this species is immobile in soils.