Zinc methacrylate

Bioaccumulation: aquatic / sediment

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

Using the correlation log K / log P_OW, the log P_OWof 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 P_OWs of the reference items. Therefore, the corresponding log P_OWis 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 P_OWs of the reference items. Therefore, the corresponding log P_OW 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 Kow 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 Kow, linear fit) was determined using the literature values for log Kow 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 Kow values of the reference items. Therefore, at neutral conditions the log Kow 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 Kow of 0.786 lies within the range of log Kow values of the reference items. Using the program EPI Suite (version 4.1), methacrylic acidhas a calculated log Kow 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 Kow of < 0.3 at neutral conditions and a log Kow 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).