Exo-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl acrylate

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2017-05-23

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
Isobornyl acrylate and Isobornyl methacrylate are structurally very similar esters of the same alcohol moity (Isoborneol) and very similar acid moities (acrylic acid and methacrylic acid) with only difference is one additional methyl group in the structure of methacrylic acid in contrast to acrylic acid.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Purities of the target chemical Isobornyl acrylate and the read across substance Isobornylmethacrylate are in the same order:
The typical reactivee ster content of Isobornyl acrylate is > = 98.5 %
The analytical purity of the read across substance Isobornyl methacrylate in the adsorption/desorption test was 99.4 % (reactive ester content)

3. ANALOGUE APPROACH JUSTIFICATION
Adsorption/desorption correlates with log Kow of a substance.
Log Kow of the read across substance Isobornyl methacrylate is 5.09 and therefore higher than log Kow of the target substance Isobornyl acrylate (log Kow=4.52). A read across with Isobornyl methacrylate for the end point adsorptio/desorption would represent a worst case and is therefore justified.

4. DATA MATRIX
see attached justification

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))

Deviations:

no

Key result

Type:

log Koc

Value:

3.71 dimensionless

Temp.:

25 °C

Remarks on result:

other: HPLC-Merthod

Determination of the dead timet0

Dead time marker	tR/min 1 st Measurement	tR/ min 2 nd Measurement	tR/min Mean
Formamide	1.708	1.708	1.708

 

Dead time to = 1.71

Calibration data-1stmeasurement

Calibration substance	1st lnj. tR/min	k	log	logKoca
Acetanilide	2.168	0.27	-0.57	1.25
Atrazin	2.603	0.52	-0.28	1.81
Triadimenol	3.568	1.09	0.04	2.40
Linuron	4.115	1.41	0.15	2.59
Pyrazophos	7.325	3.29	0.52	3.65
Diclofop-methyl	10.279	5.02	0.70	4.20
4,4' DDT	34.548	19.23	1.28	5.63

Regression:1ogK0c=a+b·logk

Parameters:

a 2.444

b = 2.408

r2= 0.9919

logK0c ofthe test item-1stmeasurement

Testltem	1st lnj. tR/min	k	log	logKoca
Isobornyl methacylate	7.567	3.43	0.54	3.73

 

Calibration data-2 ndmeasurement

Calibration substance	1st lnj. tR/min	k	log	logKoca
Acetanilide	2.174	0.27	-0.56	1.25
Atrazin	2.609	0.53	-0.28	1.81
Triadimenol	3.566	1.09	0.04	2.40
Linuron	4.135	1.42	0.15	2.59
Pyrazophos	7.338	3.30	0.52	3.65
Diclofop-methyl	10.427	5.10	0.71	4.20
4,4' DDT	35.638	19.87	1.30	5.63

Regression:1ogK0c=a+b·log k

Parameters:

a =2.435

b = 2.397

r2= 0.9926

logK0c ofthe test item-2 ndmeasurement

Testltem	1st lnj. tR/min	k	log	logKoca
Isobornyl methacylate	7.510	3.40	0.53	3.71

 

Result: mean adsorption coefficient logKoc of 3.7.

Validity criteria fulfilled:

yes

Conclusions:

Log Koc of Isobornyl methacrylate was measuerd in OECD 121 Guideline , HPLC Method. Result. Log Koc=3.71

Executive summary:

Adsorption/desorption of Isobornyl acrylate was assessed based on read across with Isobornyl methacrylate for which test data are available.

As adsorption/desorption correlates with log Kow of a substance and log Kow of the read across substance Isobornyl methacrylate is 5.09 and therefore higher than log Kow of the target substance Isobornyl acrylate (log Kow=4.52), a read across with Isobornyl methacrylate for the end point adsorption/desorption would represent a worst case and is therefore be justified.

Log Koc of Isobornyl methacrylate was measured in OECD 121 Guideline test, HPLC Method. Result. Log Koc=3.71. Log Koc of Isobornyl acrylate is expected to be in the same order or slightly lower.

As the predicted log Koc is lower than the trigger value of 4, a high potential of adsorption to soil and sediment is not expected.

Description of key information

Adsorption/desorption of Isobornyl acrylate was assessed based on read across with Isobornyl methacrylate for which test data are available.

As adsorption/desorption correlates with log Kow of a substance and log Kow of the read across substance Isobornyl methacrylate is 5.09 and therefore higher than log Kow of the target substance Isobornyl acrylate (log Kow=4.52), a read across with Isobornyl methacrylate for the end point adsorption/desorption would represent a worst case and is therefore be justified.

Log Koc of Isobornyl methacrylate was measured in OECD 121 Guideline test, HPLC Method. Result. Log Koc=3.71. Log Koc of Isobornyl acrylate is expected to be in the same order or slightly lower.

As the predicted log Koc is lower than the trigger value of 4, a high potential of adsorption to soil and sediment is not expected.

Key value for chemical safety assessment

Koc at 20 °C:

3.71