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Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

Additional information

A summary of physico-chemical properties of the dimerised fatty acids and their derivatives is provided in the tables below. Table 1 contains relevant endpoints from Sec. 4.1 (Appearance) to 4.7 (Partition coefficient) and Table 2 from Sec. 4.8 (Water solubility) to 4.22 (Viscosity). As UVCB substances are derived from natural sources with highly variable compositions, some measures of physico-chemical properties are inapplicable or not accurate enough for a trend analysis. A detailed justification for the grouping of chemicals and read-across is provided in the technical dossier (see IUCLID Section 13).

Table 1. Summary of physico-chemical endpoints for dimerised fatty acids (I) 

Chemical Name

CAS No.

Appearance

Melting / freezing point

Boiling point

Density

Vapour pressure

Partition coefficient (log Pow)

Fatty acids, C16-18 and C18-unsaturated, branched and linear

(monomer)

68955-98-6

Viscous liquid to solid

23 °C to 32 ° C (pour point)

decomposition

Experimental result:

0.90-0.91 g/mL at 19°C

Weight of Evidence:

<1 Pa at 25 °C

 

Experimental result:

Log Kow 4.9 at 25 °C

 

Judged to be >4

 

Octadecanoic acid, branched and linear

(hydrogenated monomer)

68201-37-6

Paste solid

49 °C

(pour point)

decomposition

Experimental result:

0.9 g/mL at 19 °C

Weight of Evidence:

<1 Pa at 25 °C

 

Experimental result:

Log Kow 5.6 — 6.1

 

Judged to be >4

Isooctadecanoic acid

30399-84-9

liquid

-21 °C

decomposition

Experimental result:

0.9 g/mL at 19 °C

(Q)SAR:

0.000445 Pa at 25°C

(Q)SAR:
Log Kow 7.87

The estimation refers to the isooctdecanoic acid in unique form.

Judged to be >4

Fatty acids, C16 -18 and C18-unsaturated, dimerized

71808-39-4

liquid

11 °C

decomposition

Experimental result:

0.92 to 0.94 g/mL at 19 °C

Weight of Evidence:

<1 Pa at 25 °C

Experimental result

Log Kow 2.4 — 7.5

 

Judged to be >4

Fatty acids, C18-unsaturated, dimers

61788-89-4

liquid

-18 °C to -12 °C

decomposition

Experimental result:

0.95-0.96 g/mL at 19°C

Weight of Evidence:

<1 Pa at 25 °C

Experimental result:

Log Kow 1 — 2.5

 

Judged to be >4

Fatty acids, C18-unsaturated, dimers, hydrogenated

68783-41-5

liquid

- 15 °C

decomposition

Experimental result:

0.95 g/mL at 19 °C

Weight of Evidence:

<1 Pa at 25 °C

Experimental result.

Log Kow 0.7 — 6.2

 

Judged to be >4

 

Fatty acids, C18-unsaturated, trimers

68937-90-6

Liquid

-3 °C

decomposition

Experimental result:

0.97 g/mL at 19 °C

Weight of Evidence:

<1 Pa at 25 °C

Experimental result:

Log Kow : 2.2->6 (8.9)

Judged to be >4

Table 2. Summary of physico-chemical endpoints for dimerised fatty acids (II) 

Chemical Name

CAS No.

Water solubility

Surface tension

Flash point

Dissociation constant

Viscosity

Fatty acids, C16-18 and C18-unsaturated, branched and linear

68955-98-6

Experimental result:

0.6 mg/L

Experimental result:

32.5 mN/m at 30 °C

Experimental result:

204 °C at 101.3 kPa

(Q)SAR:

pKa 4.72 — 4.75 at 25 °C

Experimental result: 21 to 27 mPa s at 40 °C

 

Octadecanoic acid, branched and linear

68201-37-6

Experimental result: 2.5 mg/L

Experimental result:

30 mN/m at 30 °C

Experimental result:

208 °C at 101.3 kPa

(Q)SAR:

pKa 4.72 — 4.75 at 25 °C

Experimental result:

24 mPas at 50 °C

Isooctadecanoic acid

30399-84-9

Experimental result:

0.24 mg/L

Experimental result:

32 mN/m at 23.7 °C

Experimental result:

208 °C at 101.3 kPa

(Q)SAR:

pKa 4.75 at 25 °C

Experimental result:

39 mPas at 40 °C

Fatty acids, C16-18 and C18-unsaturated, dimerized (crude dimer)

71808-39-4

Experimental result:

<0.41 mg/L

(water solubility below detection limit)

Experimental result:

30 mN/m at 30 °C

Experimental result:

226 °C at 101.3 kPa

Not required

Experimental result: 21 to 27 mPas at 40 °C

Fatty acids, C18-unsaturated, dimers

61788-89-4

Experimental result:

<0.12 mg/L

(water solubility below detection limit)

Experimental result:

33.3 mN/m at 24 °C

Experimental result:

304 °C at 101.3 kPa

Not required

Experimental result: 2255 to 1827mPas at 40°C

Fatty acids, C18-unsaturated, dimers, hydrogenated

68783-41-5

Experimental result:

< 0.52 mg/L

(water solubility below detection limit)

Experimental result:

32.3 mN/m at 24 °C

Experimental result:

300 °C at 101.3 kPa

Not required

Experimental result: 2671 mPas at 40 °C

Fatty acids, C18 -unsaturated, trimers

68937-90-6

Experimental result:

< 0.37 mg/L

(water solubility below detection limit)

Experimental result:

45 mN/m at 24.5 °C

Experimental result:

350 °C at 101.3 kPa

Not required

Experimental result: 7664 mPas at 40 °C

It can be concluded that the physico-chemical properties are similar or follow a regular pattern over the category. The patterns observed depend on whether the substance is predominantly monomer (CAS Nos. 68955-98-6, 68201-37-6, 30399-84-9), or it is predominantly oligomer (dimers: CAS Nos. 71808-39-4, 61788-89-4, 68783-41-5, or trimer: CAS No. 68937-90-6).

Endpoints demonstrating similarity: boiling point (decomposition), density (0.9-1.0 g/cm3), vapour pressure (low volatility), partition coefficient (log Kow > 4), surface tension (30-45 mN/m at room temperature), flash point (high: 200-350 °C).

Endpoints following regular trends/patterns: water solubility (for predominantly monomers: 0.2 - 15 mg/L, for predominantly oligomers below any detection limit under 1 mg/L), dissociation constant (calculated only for predominantly monomers, not required for predominantly oligomers), viscosity (low for monomers, considerably higher for dimers and the highest for trimer; exception: the value for crude dimer, CAS No. 71808-39-4, is in the range characteristic for predominantly monomers).