Barium 4-dodecylphenolate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

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

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

JUSTIFICATION FOR READING ACROSS INFORMATION FOR PARTITION COEFFICIENT
A study does not need to be conducted for this substance, as it is considered to be neither scientifically necessary nor technically possible.
The octanol/water partition coefficient, Pow, is defined as the ratio of the equilibrium concentrations of a dissolved substance in each of the phases in a two-phase system consisting of octanol and water. It is a key parameter in studies of the environmental fate of organic substances, indicating the potential for bioaccumulation and soil absorption. Whereas this may also be applicable for organometallic substances, it does not pertain to barium 4-dodecylphenolate because of its inorganic nature. For inorganic substances, the determination of a partition coefficient is not considered to be required (ECHA Guidance on information requirements and chemical safety assessment, Chapter R.7a: Endpoint specific guidance, section R.7.1.8.4; July 2017); since barium 4-dodecylphenolate is an inorganic substance in accordance with the definitions of the International Union of Pure and Applied Chemistry (IUPAC) because of its ionic structure, waiving in accordance with Regulation (EC) No 1907/2006, Annex VII, Section 7.8, Column 2, is also justified. In conclusion, the conduct of further experimental verification is considered to be neither technically nor scientifically feasible, and for the reasons stated above derogation from testing is hereby applied for.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The environmental fate and distribution of the dissociation products of barium 4-dodecylphenolate in water are better assessed according to the dissociation products in water as follows:
(i) the mechanisms for partitioning of Ba2+ in environmental media, including the adsorption and/or absorption by organic matter and living cells, are understood to be different from those traditionally attributed to carbon-based substances (see IUCLID section 5.4 for information on the partitioning of barium in the environment). Thus, octanol/water partitioning has little relevance to ionic barium. In order to measure an octanol/water partition coefficient, it is necessary to determine the concentration in each phase (as in OECD method 107), or to conduct an HPLC assay (as in OECD method 117). However, barium is a metallic element that exists only in an ionic form in solution. The solubility of divalent barium cations in organic solvents such as octanol can be expected to be very low. Because of the unlikely partitioning of barium cations into the octanol phase, it is not appropriate to determine the partition coefficient by direct quantification of barium in both phases. Similarly, any aqueous HPLC mobile phase will cause dissociation of inorganic barium compounds, and thus not allow the determination of a Pow by this method.
(ii) regarding the partitioning behaviour of the organic constituent, the atom/fragment contribution method (KOWWIN™ Program Version 1.68; EPI Suite™) estimated the following LogKow of phenol, dodecyl-, branched (CAS # 121158-58-5): 6.2595.

An estimation of the log Pow of barium 4-dodecylphenolate is not possible with the KOWWIN™ Program. Thus, the conduct of experimental verification for the pure substance is considered to be scientifically unjustified and the experimental verification on the dissociation products neither technically or scientifically feasible.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Source: phenol, dodecyl-, branched (CAS # 121158-58-5) (see source study records; purity is not of relevance for this endpoint)
Target: barium 4-dodecylphenolate (purity is not of relevance for this endpoint)

3. ANALOGUE APPROACH JUSTIFICATION
see justification given above

4. DATA MATRIX
not required

Reason / purpose for cross-reference:

read-across: supporting information

GLP compliance:

not specified

Remarks on result:

other: please refer to the field `Justification for type of information´

Conclusions:

A study does not need to be conducted for this substance, as it is considered to be neither scientifically necessary nor technically possible.

The octanol/water partition coefficient, Pow, is defined as the ratio of the equilibrium concentrations of a dissolved substance in each of the phases in a two-phase system consisting of octanol and water. It is a key parameter in studies of the environmental fate of organic substances, indicating the potential for bioaccumulation and soil absorption. Whereas this may also be applicable for organometallic substances, it does not pertain to barium 4-dodecylphenolate because of its inorganic nature. For inorganic substances, the determination of a partition coefficient is not considered to be required (ECHA Guidance on information requirements and chemical safety assessment, Chapter R.7a: Endpoint specific guidance, section R.7.1.8.4; July 2017); since barium 4-dodecylphenolate is an inorganic substance in accordance with the definitions of the International Union of Pure and Applied Chemistry (IUPAC) because of its ionic structure, waiving in accordance with Regulation (EC) No 1907/2006, Annex VII, Section 7.8, Column 2, is also justified.

Instead of the determination of a Pow value, the environmental fate and distribution of the dissociation products of barium 4-dodecylphenolate in water are better assessed according to the dissociation products in water as follows:

(i) the mechanisms for partitioning of Ba2+ in environmental media, including the adsorption and/or absorption by organic matter and living cells, are understood to be different from those traditionally attributed to carbon-based substances (see IUCLID section 5.4 for information on the partitioning of barium in the environment). Thus, octanol/water partitioning has little relevance to ionic barium. In order to measure an octanol/water partition coefficient, it is necessary to determine the concentration in each phase (as in OECD method 107), or to conduct an HPLC assay (as in OECD method 117). However, barium is a metallic element that exists only in an ionic form in solution. The solubility of divalent barium cations in organic solvents such as octanol can be expected to be very low. Because of the unlikely partitioning of barium cations into the octanol phase, it is not appropriate to determine the partition coefficient by direct quantification of barium in both phases. Similarly, any aqueous HPLC mobile phase will cause dissociation of inorganic barium compounds, and thus not allow the determination of a Pow by this method.

(ii) regarding the partitioning behaviour of the organic constituent, the atom/fragment contribution method (KOWWIN™ Program Version 1.68; EPI Suite™) estimated the following LogKow of phenol, dodecyl-, branched (CAS # 121158-58-5): 6.2595.

An estimation of the log Pow of barium 4-dodecylphenolate is not possible with the KOWWIN™ Program. Thus, the conduct of experimental verification for the pure substance is considered to be scientifically unjustified and the experimental verification on the dissociation products neither technically or scientifically feasible.
In conclusion, the conduct of further experimental verification is considered to be neither technically nor scientifically feasible, and for the reasons stated above derogation from testing is hereby applied for.

Description of key information

The partition coefficient of the substance barium 4-dodecylphenolate is not considered to be relevant.

Additional information

A study does not need to be conducted for this substance, as it is considered to be neither scientifically necessary nor technically possible.

 

The octanol/water partition coefficient, Pow, is defined as the ratio of the equilibrium concentrations of a dissolved substance in each of the phases in a two-phase system consisting of octanol and water. It is a key parameter in studies of the environmental fate of organic substances, indicating the potential for bioaccumulation and soil absorption. Whereas this may also be applicable for organometallic substances, it does not pertain to barium 4-dodecylphenolate because of its inorganic nature. For inorganic substances, the determination of a partition coefficient is not considered to be required (ECHA Guidance on information requirements and chemical safety assessment, Chapter R.7a: Endpoint specific guidance, section R.7.1.8.4; July 2017); since barium 4-dodecylphenolate is an inorganic substance in accordance with the definitions of the International Union of Pure and Applied Chemistry (IUPAC) because of its ionic structure, waiving in accordance with Regulation (EC) No 1907/2006, Annex VII, Section 7.8, Column 2, is also justified.

 

Instead of the determination of a Pow value, the environmental fate and distribution of the dissociation products of barium 4-dodecylphenolate in water are better assessed according to the dissociation products in water as follows:

 

(i) the mechanisms for partitioning of Ba2+ in environmental media, including the adsorption and/or absorption by organic matter and living cells, are understood to be different from those traditionally attributed to carbon-based substances (see IUCLID section 5.4 for information on the partitioning of barium in the environment). Thus, octanol/water partitioning has little relevance to ionic barium. In order to measure an octanol/water partition coefficient, it is necessary to determine the concentration in each phase (as in OECD method 107), or to conduct an HPLC assay (as in OECD method 117). However, barium is a metallic element that exists only in an ionic form in solution. The solubility of divalent barium cations in organic solvents such as octanol can be expected to be very low. Because of the unlikely partitioning of barium cations into the octanol phase, it is not appropriate to determine the partition coefficient by direct quantification of barium in both phases. Similarly, any aqueous HPLC mobile phase will cause dissociation of inorganic barium compounds, and thus not allow the determination of a Pow by this method.

 

(ii) regarding the partitioning behaviour of the organic constituent, the atom/fragment contribution method (KOWWIN™ Program Version 1.68; EPI Suite™) estimated the following LogKow of phenol, dodecyl-, branched (CAS # 121158-58-5): 6.2595.

 

An estimation of the log Pow of barium 4-dodecylphenolate is not possible with the KOWWIN™ Program. Thus, the conduct of experimental verification for the pure substance is considered to be scientifically unjustified and the experimental verification on the dissociation products neither technically or scientifically feasible.

In conclusion, the conduct of further experimental verification is considered to be neither technically nor scientifically feasible, and for the reasons stated above derogation from testing is hereby applied for.