Registration Dossier

Diss Factsheets

Administrative data

Endpoint:
bioaccumulation in aquatic species: fish
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
the study does not need to be conducted because the substance has a low potential for bioaccumulation based on log Kow <=3
Cross-reference
Reason / purpose for cross-reference:
data waiving: supporting information
Reference
Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 30 May 2012 to 11 January 2013
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
this study was reliable with restrictions because the validity criteria range < 0.1 was not fulfilled for the partition coefficient of neutral form of zinc methacrylate.
Qualifier:
according to guideline
Guideline:
OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)
Deviations:
not specified
Qualifier:
according to guideline
Guideline:
EU Method A.8 (Partition Coefficient)
Deviations:
not specified
GLP compliance:
yes (incl. QA statement)
Type of method:
HPLC method
Partition coefficient type:
octanol-water
Analytical method:
high-performance liquid chromatography
Key result
Type:
log Pow
Partition coefficient:
< 0.3
pH:
ca. 6
Remarks on result:
other: neutral pH
Key result
Type:
log Pow
Partition coefficient:
ca. 0.786
pH:
ca. 2.4
Remarks on result:
other: acidic pH
Details on results:
Using the correlation log K / log POW, the log POW of the peak of test item zinc methacrylate was calculated as <0.3
Using the correlation log K / log POW, the log POW of the peak of test item zinc methacrylate was calculated as 0.786 ± 0.002 (mean ± standard deviation).

Results:

Measurement Data Neutral pH

The retention times of the test item are presented in the following table:

Result, Measurements at Neutral pH Value

Measurement

RT

 

min.

Measurement 1

1.587

Measurement 2

1.586

Measurement 3

1.593

Mean

1.589

Standard deviation

0.004

The calculated values are presented in the following table:

Measurement

K

log K

log POW

Measurement 1

0.0052

-2.2863

-3.170

Measurement 2

0.0045

-2.3430

-3.288

Measurement 3

0.0090

-2.0471

-2.674

Mean

 

 

-3.044

Standard deviation

 

 

0.326

log POWwas calculated from the capacity factor as follows: log POW= (logK + 0.7571) / 0.4824

Test Item Zinc Methacrylate, Measurements at Acidic pH Value

The retention times of the test item are presented in the following table:

Measurement

RT

 

min.

Measurement 1

2.215

Measurement 2

2.213

Measurement 3

2.216

Mean

2.215

Standard deviation

0.002

The calculated values are presented in the following table:

Measurement

K

log K

log POW

Measurement 1

0.4264

-0.3702

0.786

Measurement 2

0.4251

-0.3715

0.783

Measurement 3

0.4271

-0.3695

0.787

Mean

 

 

0.786

Standard deviation

 

 

0.002

log POWwas calculated from the capacity factor as follows: log POW= (log K + 0.7478) / 0.4803

Using the correlation log K / log POW, the log POWof the peak of test item zinc methacrylate was calculated as -3.044 ± 0.326 (mean ± standard deviation). The peak lies in the dead time of the method and not within the range of log POWs of the reference items. Therefore, the corresponding log POWis stated as < 0.3.

Result, Measurements at Acidic pH Value

Using the correlation log K / log POW, the log POW of the peak of test item zinc methacrylate was calculated as 0.786 ± 0.002 (mean ± standard deviation).

Validity, Measurements at Neutral pH Value

The validity criteria and results (mean±sd) are presented in the following table:

Peak

Parameter

Criterion

Found

Assessment

1

Range (Max – Min. log POW)

< 0.1

0.614

not valid*

Value withinofItems

0.30 - 2.70

-3.044*

not valid*

*The peak of the test item lies in the dead time of the method at neutral pH and not within the range of log POWs of the reference items. Therefore, the corresponding log POW is stated as < 0.3.

Validity, Measurements at Acidic pH Value

The validity criteria and results (mean±sd) are presented in the following table:

Peak

Parameter

Criterion

Found

Assessment

1

Range (Max – Min. log POW)

< 0.1

0.004

valid

Value withinofItems

0.30 - 2.70

0.786

valid

Conclusions:
It is concluded that the test item has a log POW of < 0.3 at neutral conditions and a log POW of 0.786 at acidic conditions.
Executive summary:

This study was performed according to the OECD 117 and EU Method A.8 using a HPLC method with a C18 column under GLP. A test item injected on such a column partitions between the mobile solvent phase and the hydrocarbon stationary phase as it is transported along the column by the mobile phase. The test items are retained in proportion to their hydrocarbon-water partition coefficient, with hydrophilic chemicals eluted first and lipophilic chemicals last. The retention times of the peaks of the test item are compared with retention times of reference substances with known hydrocarbon-water partition coefficients. Two measurements were performed, one with neutral pH and one with acidic pH (new delivery test item). Six reference items with different retention times and thio urea for the determination of the dead time were used to produce a calibration curve, since retention time on hydrophobic columns and log POW are correlated. The reference items were chosen on behalf of the pre-tests. First, a solution of the reference items was analysed with HPLC, then a solution of the test item; and finally again the solution with the reference items. Each analysis was performed three times, totalling to nine runs. For each reference item, the capacity factor K was calculated from the retention time of thio urea and the retention time of the respective reference item. A calibration function (log K versus log POW, linear fit) was determined using the literature values for log POW of the reference items and the retention times in the six determinations. For the neutral pH, the chromatogram of the test item gave one peak at approx. 1.6 minutes, which lies within the dead time of the method and not within the range of log POWs of the reference items. Therefore, at neutral conditions the log POW is stated as < 0.3. At acidic measurement conditions, the peak of the test item has a retention time of approx. 2.2 minutes. The corresponding log POW of 0.786 lies within the range of log POWs of the reference items. Using the program EPI Suite (version 4.1), methacrylic acidhas a calculated log POW of 0.99. The estimated value, using the program EPI Suite is confirmed by this study.

It is thus concluded that the test item has a log POW of < 0.3 at neutral conditions and a log POW of 0.786 at acidic conditions. This study was reliable with restrictions because the validity criteria range < 0.1 was not fulfilled for the partition coefficient of neutral form of the test item (Brickmann, 2013).

Data source

Materials and methods

Results and discussion

Applicant's summary and conclusion