Registration Dossier

Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

Additional information

C16 Alkylamidopropyltrimethylammonium Chloride is a white waxy solid at 20°C and 1013 hPa (visual assessment).

 

The melting point of C16 Alkylamidopropyltrimethylammonium Chloride was determined in two experiments. In the melt microscope the test item changes at an onset-temperature of 80 °C, at 150 °C approximately half of the product is “melted”. In the DSC experiment reversible endothermic effects in the range of 89 °C (extrapolated onset) and 98 °C (extrapolated end) were recorded.

 

The boiling point of C16 Alkylamidopropyltrimethylammonium Chloride was determined according to OECD guideline 103 using the Differential Scanning Calorimetry (DSC) method. Above 80 °C no significant weight loss was recorded up to 221 °C (onset temperature). Then the weight continuously decreased and reached a loss of approx. 100 % at 410 °C.

At 205 °C (onset) the DSC test traces an endothermic signal which could be allocated to a boiling behaviour, however, from the visual inspection (“above 185 °C the sample becomes jellylike and started to fume”) this endotherm has to be allocated to a degradation process.

This assumption can also be deduced from the literature, as it is well known that quaternary components tend to degrade above temperatures of 120 °C (Hoffmann degradation; reversed Menshutkin reaction).

No boiling point could be detected. The substance decomposes at a temperature > 185 °C.

 

The density of C16 Alkylamidopropyltrimethylammonium Chloride was determined according to OECD guideline 109 by means of a gas displacement pycnometer. A value of 1.029 g/cm³ at 20 °C was obtained.

 

According to the REACH Regulation, Annex VII, column 2 the study does not need to be conducted if the substance is marketed or used in a non solid or granular form. The substance is exclusively marketed and used in solution.

 

The vapour pressure of C16 Alkylamidopropyltrimethylammonium Chloride was estimated by means of calculation on a structurally related substance (N-[3-(Dimethylamino)propyl]hexadecan-1-amide) . The software used for the calculation was ACD/Percepta 14.0.0 (Build 2726). A value of 0.00000027 Pa was obtained at 20 °C.

The vapour pressure of C16 Alkylamidopropyltrimethylammonium Chloride was calculated to be 2.77E-12 Pa at 25°C using the Modified Grain Method (EpiSuite v4.11, MPBVP v1.43).

The source substance N-[3-(Dimethylamino)propyl]hexadecan-1-amide used for calculation of the vapour pressure of the registration substance is non-quaternised and non-ionic but otherwise identical in head-group and carbon chain length and thus represents a worst case. Due to the ionic nature of the target substance, the vapour pressure is expected to be even lower.

 

The weighted log Kow was calculated for the quaternised ammonium constituents of the substance using the software ACD /Labs, Release 14.0.0 (Build 272627, Nov. 2014). A value of 2.49 was obtained.

Similar results were also obtained with the source substances Stearic acid 3-(dimethylaminopropyl) amide (2.01 at 20°C, pH7) and Cetrimonium chloride (3.08 at 25°C). The results are used for justification of the read-across approach.

 

The water solubility of C16 Alkylamidopropyltrimethylammonium Chloride was determined according to ASTM no. E 1148 -2, Method A2 by measurement of the critical micelle concentration (CMC) using the turbidimetric method. The turbidity was addressed by measurement of the light extinction at a wavelength of 620 nm. The water solubility, corresponding to the CMC of the substance was determined to be 203 mg at 20.1°C.

Similar results were also obtained with the source substances Stearic acid 3-(dimethylaminopropyl) amide (CMC: 220 mg/L at 25°C) and Cetrimonium chloride (CMC: 240 mg/L at 25°C). The results are used for justification of the read-across approach.

 

The surface tension of the substance was determined according to OECD guideline 115 using the ring method. At 25 °C the surface tension was determined to be 39.4 (± 0.28) mN/m.

Similar results were also obtained with the source substances Stearic acid 3-(dimethylaminopropyl) amide (37.86 mN/m at 0.22 g/L) and Cetrimonium chloride (33 mN/m at 1 g/L). The results are used for justification of the read-across approach.

 

The flash point of the substance was determined according to EU method A.9 (DIN EN ISO 2719 (Pensky-Martens, closed cup). The commercially available version of the substance containing 40% 1,2 -propylene glycol was used. The flashpoint was determined to be 108.0°C.

 

According to REACH, Annex VII, column 2 the study does not need to be conducted for solids, if the substance has a melting point ≤ 160°C. A melting point between 89 and 98°C was determined for the substance.

 

The substance is exclusively manufactured in solution. During the whole life cycle it is never being isolated from the solution. It is scientifically not justified to determine the flammability properties of the solution, because the solvent (not the substance) determines the flammability.

 

In accordance with column 2 of REACH regulation annex VII, explosive properties testing does not need to be conducted as there are no chemical groups associated with explosive properties in the molecule.

 

In accordance with column 2 of REACH regulation annex VII, oxidising properties testing does not need to be conducted as there are no chemical groups associated with oxidising properties in the molecule.