N-[3-(dimethylamino)propyl]docosanamide

Endpoint summary

Additional information

DIMAPDO is a white solid at 20°C and 1013 hPa (EPA OPPTS 830.6303 (Physical State)).

The melting point of DIMAPDO was investigated in a study conducted according to OECD Guideline 102, adopted 27 July 1995, and ASTM E 537-86 using differential scanning calorimetry. The melting point was determined to be 79.4°C ± 0.5°C at atmospheric pressure.

The boiling point of DIMAPDO was investigated in a study conducted according to OECD Guideline 103, adopted 27 July 1995, and ASTM E537-86 using differential scanning calorimetry. Based on the results a boiling point could not be determined up to a temperature of 300°C at 101.325 kPa.

The relative density of DIMAPDO was investigated in a study conducted according to OECD Guideline 109 (Density of Liquids and Solids; adopted 27 July 1995) and UNE-EN ISO 1183 -1 using the pycnometer method. The relative density (D20/4) was determined to be 0.947 ± 0.001 at 20°C.

In accordance with column 2 of REACH Annex VII 7.14, a study on granulometry does not need to be conducted if the substance is marketed or used in a non solid or granular form: The substance is marketed as solid flakes.

According to REACH Annex XI, 2. the determination of the vapour pressure of DIMAPDO is not necessary, because it is technically not possible: the expected value of vapour pressure for the pure substance cannot be measured due to residual content of solvent which results in a higher solvent vapour pressure than test substance vapour pressure. The residual content of solvent cannot be reduced below the limit of measurement with reasonable effort. A supporting study is available, in which the vapour pressure was calculated via EPIWIN v4.00, MPBPVP v1.43 as 7.1E-009 Pa (Modified Grain Method) at 25°C.

The dissociation constant of DIMAPDO was calculated using the freely accessible online version of I-Lab 2.0 Algorithm Version: v5.0.0.184. The calculation yielded a pka (Base) of 9.2±0.4 at 25°C. Therefore test substance is present to a larger extent as protonated amine as well as to a minor extent as neutral form (free amine) at environmentally relevant pH in the range of pH 4-9. As this can have a marked effect on the partition coefficient, the log Kow was estimated from the solubilities of DIMAPDO hydrochloride.

Based on the pKa (Base) of 9.2 ± 0.4 the following distributions of free and protonated amine are present at different pH:

	free amine [%]	protonated amine [%]
pH 4	0	100
pH 7	0.5	99.5
pH 9	38.7	61.3

 

The water solubility of DIMAPDO hydrochloride is reported to be below 0.1 mg/L at 25°C. However, the registration substance is a surface active substance with very low water solubility and a strong base which is mostly protonated under environmental conditions therefore the determination of water solubility according to OECD guideline 105 using the flask method is not appropiate and the result should be treated with care.

Surfactants show a complex solubility behaviour due to aggregation. The single molecule concentration reaches a limiting value at the critical micelle concentration and remains approximately constant when the total concentration further increases. Therefore the critical micelle concentration (cmc) of DIMAPDO hydrochloride was determined according to OECD 115, adopted 25 July 1995, and ISO 304 -1985 via surface tension measurement. The cmc of DIMAPDO hydrochloride was 9 mg/L at 25°C.

The solubility of DIMAPDO hydrochloride in n-Octanol was determined according to OECD guideline 105, 27 July 1995, adapted for n-Octanol by flask method.The average solubility of DIMAPDO hydrochloride was 6.1 ± 0.2 g/L at 25.0 ± 0.2°C.

According to EU method A.8, 31 May 2008 the n-octanol/water partition coefficient (log Kow) of DIMAPDO was estimated by calculation based on the solubility of the test substance in n-Octanol and water. Therefore the log Kow of DIMAPDO hydrochloride is 2.85 at 25°C.

The surface tension of DIMAPDO hydrochloride was determined according to OECD Guideline 115 (adopted 27 July 1995) and ISO Standard 304-1985 using the plate method. The surface tension had a minimum of 38.47 mN/m at 10.21 mg/L. The substance is surface active.

The flash point of DIMAPDO could not be determined according to EU Method A.9 (Flash-Point; EC 440/2008) with a starting temperature of 50°C and a final temperature of 200°C (Continuously Closed Cup Method (CCCFP)). Therefore the flash point of DIMAPDO is >200ºC at 101.3 kPa.

According to REACH regulation Annex VII, 7.12, column II, a test on auto flammability does not need to be conducted for solids with a melting point below 160°C. The melting point of the test substance is 79.4°C ± 0.5°C.

The flammability of DIMAPDO was investigated in a study conducted according to EU-Method A.10. In a preliminary test, the test item did not propagate combustion either by burning with flame or smouldering along 200 mm of the powder train within the 10 minutes test period. Therefore the main test was not necessary to be conducted. The test substance is not highly flammable.

Explosive properties testing does not need to be conducted as there are no chemical groups associated with explosive properties in the molecule.

Oxidising properties testing does not need to be conducted on the basis of chemical structure.