Reaction Mass of Cyclohexanepropanol, 2,2,6-trimethyl-a-propyl-, (alpha.R,1R,6S)- and Cyclohexanepropanol, 2,2,6-trimethyl-a-propyl-, (alpha.S,1R,6S)-

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental phase from 2014-09-19 to 2014-09-29

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was conducted according to an internationally recognised method, and under GLP. No deviation was reported. The test substance is considered to be adequately characterised. Therefore full validation applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 123 (Partition Coefficient (1-Octanol / Water), Slow-Stirring Method)

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

inspected on June 3 to 5, 2013 / signed on November 5, 2013

Type of method:

slow-stirring method

Partition coefficient type:

octanol-water

Analytical method:

gas chromatography

Type:

log Pow

Partition coefficient:

5.79

Temp.:

25 °C

pH:

5.85

Remarks on result:

other: isomer 1, (alpha.R,1R,6S)-

Type:

log Pow

Partition coefficient:

5.59

Temp.:

25 °C

pH:

5.85

Remarks on result:

other: isomer 2, [1a(S*),6b]- (9Cl)

Method Validation:

The analytical method on test substance was validated with satisfactory results regarding linearity, limit of quantification, accuracy, precision and specificity.

 

Table 4.7/1: Partition coefficient – results (Isomer1)

Replicate	Test	Measured concentration		Pow	Log Pow
number	duration [h]	in n-octanol [mg/L]	in aq. Phase [mg/L]		Single	Mean	SD ±	CV
1	91.34	5920	0.00852	694836	5.84	5.76	0.07	1.19
	96.52	5420	0.00964	562241	5.75
	115.63	5280	0.00882	598639	5.78
	120.64	4700	0.00990	474747	5.68
2	91.34	6300	0.00816	772059	5.89	5.80	0.06	1.00
	96.52	5100	0.00892	571749	5.76
	115.63	5640	0.00918	614379	5.79
	120.64	5140	0.00860	597674	5.78
3	91.34	6560	0.00848	773585	5.89	5.80	0.06	1.09
	96.52	4900	0.00802	610973	5.79
	115.63	5340	0.00926	576674	5.76
	120.64	5160	0.00916	563319	5.75
				log POW,Av		5.789
				slog POW,Av		0.007

 

Table 4.7/2: Partition coefficient – results (Isomer2)

Replicate	Test	Measured concentration		Pow	Log Pow
number	duration [h]	in n-octanol [mg/L]	in aq. Phase [mg/L]		Single	Mean	SD ±	CV
1	91.34	12078	0.0318	380290	5.58	5.56	0.02	0.35
	96.52	10700	0.0308	347854	5.54
	115.63	11612	0.0326	356634	5.55
	120.64	11556	0.0304	379882	5.58
2	91.34	12332	0.0302	408615	5.61	5.61	0.03	0.62
	96.52	11876	0.0269	441487	5.64
	115.63	12478	0.0296	421554	5.62
	120.64	11570	0.0316	365676	5.56
3	91.34	12494	0.0289	432318	5.64	5.62	0.03	0.47
	96.52	12416	0.0280	442796	5.65
	115.63	11580	0.0300	386515	5.59
	120.64	11942	0.0291	410660	5.61
				log POW,Av		5.589
				slog POW,Av		0.042

 

Regression analysis demonstrated that the slope of the regression line of the log Pow of the four successive samples was not significantly different from zero.Therefore equilibrium was considered to be achieved.

The recovery rates for stock solution range between 68 and 92 %.

The mass balance for isomer 1 ranges between 69 – 96 %.

The mass balance for isomer 2 ranges between 79 – 92 %.

Conclusions:

The test substance has potential to bioaccumulate in the environment, according to CLP classification criteria for aquatic chronic toxicity (log Kow > 4).

Executive summary:

The partition coefficient of the test substance was measured under GLP according to the OECD 123 guideline, slow stirring method.

The partition coefficient (n-octanol/water) (log Pow) was determined for the individual isomers of the test item at test temperature of 25 ± 1 °C and at a pH value of 5.85 from three independent replicates (test vessels) with 4 sub-replicates (samples).

Quantification was performed using validated GC-MS analytical method.

The partition coefficient was determined as:

log Pow = 5.789 ± 0.007 for isomer 1 Cyclohexanepropanol,2,2,6‑trimethyl‑a‑propyl‑, (alpha.R,1R,6S)‑and

log Pow = 5.589 ± 0.042 for isomer 2 Cyclohexanepropanol,2,2,6‑trimethyl‑a‑propyl‑, [1a(S*),6b]‑ (9Cl)

Reference 2

Endpoint:

partition coefficient

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

Based on structural similarity (diastereoisomers), no high difference is anticipated between the constituents.
Moreover, in a supporting HPLC study conducted on the source substance (Firmenich 2008), a single peak was observed, showing no significant difference between the isomers.
Therefore the result of the study will be considered for the target substance.

Further information is included in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across: supporting information

Key result

Type:

log Pow

Partition coefficient:

5.79

Temp.:

25 °C

pH:

5.85

Conclusions:

(from analogue) The substance has potential to bioaccumulate in the environment, according to CLP classification criteria for aquatic chronic toxicity (log Kow > 4).

Executive summary:

The partition coefficient of the test substance was measured under GLP according to the OECD 123 guideline, slow stirring method.

The partition coefficient (n-octanol/water) (log Pow) was determined for the individual isomers of the test item at test temperature of 25 ± 1 °C and at a pH value of 5.85 from three independent replicates (test vessels) with 4 sub-replicates (samples).

Quantification was performed using validated GC-MS analytical method.

The partition coefficient was determined as:

log Pow = 5.789 ± 0.007 for isomer 1 Cyclohexanepropanol,2,2,6‑trimethyl‑a‑propyl‑, (alpha.R,1R,6S).

A similar logKow is anticipated for the second isomer of the target substance.

Description of key information

Isomers expected to range between ca 5.59 and 5.79 (from analogue).

The substance has potential for bioaccumulation; the data is relevant for classification in aquatic chronic toxicity hazard class according to Regulation (EC) No.1272/2008 (CLP) criteria (log Kow>4).

Key value for chemical safety assessment

Log Kow (Log Pow):

5.79

at the temperature of:

25 °C

Additional information

No data is available on the substance itself.

However, a fully reliable experimental study, conducted according to a recognized OECD/EC method and under GLP, is available on an analogue (stereoisomers). Based on structural similarity, minor difference is anticipated with the present dossier substance, the read-across is considered justified for a key study, and the higher result is retained as key data (both worst-case and isomer common between source and target substances).

Despite the substance was considered as surface-active (please refer to IUCLID section 4.10), in the tests conditions, no surface-active behaviour is supposed to affect the validity of the study.