Resinoid of Commiphora erythraea (Burseraceae) obtained from the gum by ethanol extraction

Endpoint summary

Description of key information

The substance belongs to a group of Natural Complex Substances (NCS) : UVCB sub-type 3, where the source is biological and the process is refinement (See ECHA Guidance on Identification and naming of substances under REACH); such as: exudates, resinoids and concretes that are well-known to be very difficult to analytically assess. These complex UVCB substances contain a large number of constituents with different volatility and solubility (mostly low solubility); the composition can be widely unknown and being (mostly) solid(ish) and/or extremely viscous resins their physical state leads to further difficulties for testing.

 

Considering the very complex nature of the test item (UVCB, very viscous, composed of about 80-90% of unknown constituents), physico-chemical properties of the registered substance were determined from experimental testing when possible. Some endpoints were waived, based on the experience in handling and use of the substance and on the chemical structure of the known constituents. We also considered waiving based on the technical issues due to the complex nature of such UVCB substance especially when the information obtained from testing was not relevant or of practical use, and irrelevant for subsequent assessments.

The substance is a brown red paste (solid) at ambient temperature. When the substance is heated, it is extremely viscous (see endpoint 4.2). The substance contains volatile constituents leading to a relatively high measured vapour pressure and low flash point. The substance has potential for surface activity and for bioaccumulation. No hazard was identified with regard to physical properties (flammability,explosivity, oxidising properties, self-heating substance) based on Regulation (EC) 1272/2008 (CLP regulation) and GHS.

Additional information

Summary of relevant physico-chemical properties:

Endpoint (method)	Data
Appearance at 20 °C and 1 atm. (visual)	brown red paste (solid)
Melting point (OECD 102/EU A1, pour point)	pour point : 53 ± 3 °C (326 ± 3 K).
Boiling point (OECD 103/EU A2, DSC)	partially boils over the range approximately 140 to 400 °C (413 to 673 K) at 97.9 to 99.4 kPa
Relative density (OECD 109/EU A3, pycnometer)	D20/4 = 1.555
Granulometry (data waiving)	study scientifically not necessary (not granular powder)
Vapour pressure (OECD 104/EU A4, static method)	1183 Pa at 20°C and 1504 Pa at 25°C (interpolation)  Note that the result obtained on this kind of substance should be largely influence by small amounts of volatile constituents and these values don't represent the major part of the substance. Therefore the result should be considered with caution when used for subsequent assessment (worst case).
Log Kow (data waiving)	Waiving based on technical unfeasibility. Calculated values were provided on known constituents of the substance, which represent a low part of the composition of the substance (about 11%).
Water solubility (data waiving)	Waiving considering the very complex nature of the test item, the information obtained from testing is considered as not relevant or of practical use for subsequent assessments.
Surface tension (OECD 115/EU A5, ring method)	The surface tension of an aqueous solution of the test item (using a 90% saturated solution obtained with a loading rate of 1g/L) was determined to be between 55.2 and 56.5mN/m at 21.3°C± 0.5 °C. As the result is below the threshold value of 60mN/m, the substance is considered to have surface active potential, under the experimental conditions, based on EU A5 criteria. However, considering that the structure of the known constituents of the substance are not characteristic of true surfactants, that the dissolved part of the substance is not representative of the whole substance and especially that it is not the intended use of the substance (i.e. not a desired property), this conclusion should be taken with caution.
Auto-ignition temperature (EU A15/IEC 79 -4)	296°C (99.7 - 100.7 kPa)
Flash-point (EU A9, ISO 3679, ASTM D3278, equilibrium closed cup) Flammability (N.1 readily combustible solids) Flammability water & air (data waiving) Self-heating substances/mixtures (data waiving)	Flash Point=98°C: not a flammable liquid under CLP and GHS  Note that the result obtained on this kind of substance should be largely influence by small amounts of volatile constituents and the result doesn't represent the major part of the substance. No ignition in contact with a flame: not a flammable solid (CLP/GHS).    Waived based on experience in handling, testing and use, and chemical structure of the known constituents.  Not flammable if contact with air or water   Waived based on low melting point. No self-heating substance anticipated
Explosive properties (data waiving)	Waiving based on experience on this type of substance and chemical structure of known constituents. Low potential for explosive properties
Oxidising properties (data waiving)	Waiving based on technical issue and chemical structure of known constituents. Low potential for oxidizing properties.

Slight variations are possible with composition (UVCB substance).