Reaction mass of 3-O-acetyl-1,5-anhydro-4-butyl-2,4-dideoxy-2-methyl-D-xylitol and (2R,3S)-2-methyloctane-1,3-diyl diacetate

Adsorption / desorption

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

adsorption / desorption: screening

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: read-across from a guideline study

Justification for type of information:

The read-across justification is presented in the Endpoint summary Adsorption / desorption. The accompanying files are also attached there.

Reason / purpose for cross-reference:

read-across source

Key result

Type:

Koc

Value:

760 L/kg

Remarks on result:

other: read-across from Jasmal

Type:

log Koc

Value:

2.88 dimensionless

Reference 2

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

07 May - 09 June 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

This information is used for read-across to Jessemal.

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))

Version / remarks:

(2001)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))

Version / remarks:

(2008)

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

other: soil adsorption reference data

Radiolabelling:

no

Test temperature:

35°C ± 1°C

Details on study design: HPLC method:

EQUIPMENT
- Instrument: Acquity UPLC system (Waters, Milford, MA, USA)
- Detector: Acquity UPLC TUV detector (Waters)
- Column: Acquity UPLC HSS Cyano, 100 mm x 2.1 mm i.d., dp = 1.8 μm (Waters)
- Flow: 0.4 mL/min
- Injection volume: 5 µL
- UV detection: 210 nm

MOBILE PHASE
- Type: 30/70 (v/v) methanol/water
- pH: neutral (no buffers used)
- Solutes for dissolving test and reference substances: stock solutions in methanol; end solutions in 30/70 (v/v) methanol/water

DETERMINATION OF DEAD TIME
- Method: by inert substance which is not retained by the column (formamide)

REFERENCE SUBSTANCES
- Identity: Acetanilide; Monuron; 2,5-Dichloroaniline; Naphthalene; Benzoic acid phenylester; Fenthion.
- The blank solution for the mixture of reference substances was 30/70 (v/v) methanol/water.

PREPARATION OF TEST SOLUTIONS
- A 2000 mg/L test substance stock solution in methanol was diluted to obtain a solution of 100 mg/L in 30/70 (v/v) methanol/water.
- The test substance blank solution was 30/70 (v/v) methanol/water.

REPETITIONS
- Number of determinations: 2 (for reference substances and test solutions); 1 (for blank solution)

EVALUATION
- Calculation of capacity factors k': k'= (tr-t0)/t0 where tr = reterntion time, t0 = mean column dead time
- Determination of the log Koc value: via linear regression; log k' = 0.728 x log Koc - 0.924 (r = 0.942, n = 12)

Key result

Type:

log Koc

Value:

2.88 dimensionless

Temp.:

35 °C

Remarks on result:

other: peak 5 in HPLC test; Peak area: 40%. Koc= 760.

Type:

log Koc

Value:

2.87 dimensionless

Temp.:

35 °C

Remarks on result:

other: peak 4 in HPLC test; Peak area: 16%. Koc= 730.

Type:

log Koc

Value:

2.51 dimensionless

Temp.:

35 °C

Remarks on result:

other: peak 3 in HPLC test; Peak area: 8.3%. Koc= 320.

Type:

log Koc

Value:

2.42 dimensionless

Temp.:

35 °C

Remarks on result:

other: peak 2 in HPLC test; Peak area: 33%. Koc= 260.

Type:

log Koc

Value:

2.37 dimensionless

Temp.:

35 °C

Remarks on result:

other: peak 1 in HPLC test; Peak area: 3.4%. Koc= 240.

Details on results (HPLC method):

In the HPLC chromatograms of the test substance solution, several test substance peaks were observed. Measurements and results are summarized in the table below.

The test was performed at 35°C (i.e. the temperature of the column), but the log Koc value(s) obtained can be considered to represent the value(s) at an unspecified, probably ambient temperature (ca. 20°C) since no mention is made in the guidelines of the temperature at which the reference substance’s log Koc values were determined. Adsorption coefficients of the test and reference substances are assumed to vary with temperature in the same way.

Substance	tr,1 [min]	tr,2 [min]	mean tr [min] (n=2)	log Koc	Koc	Area %
Formamide (t0)	0.677	0.680	0.679
Acetanilide	1.512	1.575		1.26
Monuron	2.992	3.217		1.99
2,5-Dichloroaniline	3.692	3.940		2.55
Naphthalene	5.784	6.302		2.75
Benzoic acid phenylester	12.075	13.654		2.87
Fenthion	32.468	38.141		3.31
Test substance – peak 1	5.012	4.980	4.996	2.37	2.4 x 10^2	3.4
Test substance – peak 2	5.346	5.309	5.328	2.42	2.6 x 10^2	33
Test substance – peak 3	6.104	6.063	6.084	2.51	3.2 x 10^2	8.3
Test substance – peak 4	10.571	10.495	10.533	2.87	7.3 x 10^2	16
Test substance – peak 5	10.880	10.786	10.833	2.88	7.6 x 10^2	40

Remark: Log Koc values are based on soil adsorption reference data (according to OECD 121)

A typical chromatogram is presented in the 'attached backgorund material'.

Validity criteria fulfilled:

yes

Conclusions:

Based on the HPLC estimation method at neutral pH using soil-adsorption reference data, the log Koc for Jasmal was determined to be in the range 2.37-2.88 (covering 98.7% of the substance).

Executive summary:

The HPLC estimation method at neutral pH using soil-adsorption reference data was applied for the determination of the adsorption coefficient (Koc) of the substance. The study was performed according to EC C.19 and OECD 121 and in accordance with the principles of GLP.The mobile phase was 30/70 (v/v) methanol/water. The column temperature was 35°C. In the HPLC chromatogram of the test substance solution, three major peaks (16, 33 and 40% peak area) and 2 smaller peaks (3.4 and 8.3% peak area) were observed. The log Koc values of the major components range from 2.42 - 2.88 (Koc: 260 - 760).

Description of key information

Jessemal has a low to moderate adsorption potential based on read-across from Jasmal, for which a Koc value of 760 L/kg was determined in a study according to OECD TG 121.

Key value for chemical safety assessment

Koc at 20 °C:

760

Additional information

The adsorption/desorption potential of Jessemal is based on read-across from Jasmal. The executive summary of the Jasmal information is presented below, followed by the read-across rationale.

Jasmal Koc information

The Koc was tested in the HPLC estimation method at neutral pH using soil-adsorption reference data was applied for the determination of the adsorption coefficient (Koc) of the substance. The study was performed according to EC C.19 and OECD 121 and in accordance with the principles of GLP.The mobile phase was 30/70 (v/v) methanol/water. The column temperature was 35°C. In the HPLC chromatogram of the test substance solution, three major peaks (16, 33 and 40% peak area) and 2 smaller peaks (3.4 and 8.3% peak area) were observed. The log Koc values of the major components range from 2.42 - 2.88 (Koc: 260 - 760). The log Koc values of the minor components range from 2.37 - 2.51 (Koc ranges from 240 to 320). The Koc of 760 L/kg will be used for the risk assessment.

Adsorption potential of Jessemal using read across from data available for Jasmal (CAS# 18871-14-2).

 

Introduction and hypothesis for the analogue approach

For the multi-constituent substance Jessemal all constituents > 1% are identified. The substance consists mainly of two sub-groups of constituents, Tetrahydropyran acetate -like constituents, and Branched alkyl diacetates-type.For Jessemal no experimental adsorption/desorption data are available. In accordance with Article 13 of REACH, lacking information can be generated by means other than experimental testing, i.e. applying alternative methods such as QSARs, grouping and read-across. For assessing the (log) Koc of Jessemal the analogue approach is selected because for one of the constituents, Jasmal, an experimental (log) Koc is available, which can be used for read across.

Hypothesis: The sorption potential of Jasmal is considered to be representative for Jessemal.

Available information: For Jasmal an HPLC screening study was performed according to OECD 121 (HPLC method, Rel. 1). The log Koc selected is 2.88, Koc 760 L/kg based on the constituent with the higher Koc, covering the higher Koc constituents. The lower Koc’s are still within a factor of 3 compared to this higher Koc.

Target chemical and source chemical(s)

Chemical structures of the target chemical and the source chemical(s) are shown in the data matrix, including physico-chemical properties.

Purity / Impurities             

The major and minor constituents of Jessemal are presented in the Data matrix. The impurities < 10% are grouped based on their resemblance with Tetrahydropyran acetate -like constituents, and Branched alkyl diacetates-type.

Analogue approach justification

According to Annex XI section 1.5, read across can be used to replace testing when the similarity can be based on a common backbone and a common functional group. When using read across the result derived should be applicable for C&L and/or risk assessment and it should be presented with adequate and reliable documentation, which is presented below.

Analogue selection: For Jessemal the substance Jasmal was selected as source chemical for read-across because Jessemal ‘s constituents are the same or very similar to Jasmal’s but are present in different concentrations and for Jasmal experimental sorption information is available.

Structural similarities and differences:Jessemal andJasmal are both reaction masses containing similar Tetrahydropyran acetate-like constituents with molecular weight of 214. Jessemal also contains constituent of Branched alkyl diacetates with molecular weights of 244. These diacetates have one additional acetic ester and have an open ring structure not present in Jasmal. Jessemal hastwo minor impurities just exceeding the 1% level, one being the alcohol derivative of the Tetrahydropyran acetates and the other one of the Branched alkyl diacetates, which will not be addressed further being only very minor constituents.

Koc value selection: For the multi-constituent Jessemal the higher Koc value of Jasmal was used, because this higher Jasmal value reflects at least the Branched alkyl diacetates and is still within a factor of 3 difference of the Tetrahydropyran acetate like group.

Conversion of the effect values to Jessemal from Jasmal: A conversion is not considered necessary because both Jessemal and Jasmal have the same and/or similar constituents but in different concentrations. The Tetrahydropyran acetates and Branched alkyl diacetates present ca 50% and almost 40% of the constituents, respectively. By using the higher Koc value for Jessemal from Jasmal all constituents are sufficiently covered and the values are within a factor of 3 (< log 0.5).

Uncertainty of the prediction: There are no remaining uncertainties other than those already addressed above.

Data matrix

The relevant information on physico-chemical properties and environmental fate characteristics are presented in the data matrix below.

Conclusions on adsorption for hazard and risk assessment

For Jessemalno adsorption information is available. Read-across from Jasmal is used to fill this data gap. When using read-across, the result derived should be applicable for C&L and/or risk assessment, and be presented with adequate and reliable documentation. This documentation is presented in the current text. For the analogueJasmal, an experimentalKoc value of 760 L/kg is available from a study according to OECD TG 121, which can be used for read across to Jessemal.

Final conclusion: For Jessemal the Koc is 760 L/kg (log Koc = 2.88).

 

Data matrix to support the read across for Jessemal from Jasmal for adsorption / desorption potential

	Jessemal	Tetrahydropyran acetates	Jasmal + 3 other similar impurities	Branched alkyl diacetates	Other branched alkyl diacetates (4 impurities)
Read-across	Target	Target Major constituent	Source (and impurity)	Target Minor constituent:	Target Impurities
Chemical structures	Not applicable
Typical conc. (%)	Not applicable	20-40	<23	10-20	<22
CAS #	Not applicable	38285-49-3	18871-14-2	67634-09-7	Not applicable
Einecs	945-946-3		242-640-5
REACH registration	2018		Registered
MW	Not applicable	214	214	244	244
Phys-chem*
Log Kow	3.5# (exp.)	3.2 (est.)	3.2 - 3.7 (exp.)	3.7 (est.)	3.7 (est.)
Ws (mg/L)	714.1 (exp.)	67.8 (est.)	214.9 (exp.)	17.8 (est.)	17.8 (est.)
Environmental fate
Koc (log Koc)	760 (2.88) (Read across)	760 (2.88) (Read across)	760 L/kg (2.88) (OECD TG 121)	760 (2.88) (Read across)	760 (2.88) (Read across)

* Episuite v4.11 unless stated otherwise (i.e. ‘exp.’); # Log Kow relates to the main constituent, the range is 3.5 to 4.2.