Hydrocarbons, C12-C15, n-alkanes, isoalkanes, cyclics, < 2% aromatics

Endpoint summary

Description of key information

Hydrolysis:

Hydrolysis is a reaction in which a water molecule or hydroxide ion substitutes for another atom or group of atoms present in a chemical resulting in a structural change of that chemical. Potentially hydrolysable groups include alkyl halides, amides, carbamates, carboxylic acid esters and lactones, epoxides, phosphate esters, and sulfonic acid esters (Neely, 1985). The lack of a suitable leaving group renders compounds resistant to hydrolysis.

The chemical constituents that comprise Hydrocarbons, C12-C15, n-alkanes, isoalkanes, cyclics, < 2% aromatics (D90) consist entirely of carbon and hydrogen and do not contain hydrolysable groups. As such, it has a very low potential to hydrolyse. Therefore, this degradative process will not contribute to its removal from the environment.

Phototransformation in air

Standard tests for atmospheric oxidation half-lives are intended for single substances and are not appropriate for this complex substance. However, this endpoint is characterized using quantitative structure property relationships for representative hydrocarbon structures that comprise the hydrocarbon blocks used to assess the environmental risk of this substance with the PETRORISK model (see library tab in PETRORISK spreadsheet attached to Section 13).

Phototransformation in water

The direct photolysis of an organic molecule occurs when it absorbs sufficient light energy to result in a structural transformation. The absorption of light in the ultra violet (UV)-visible range, 110-750 nm, can result in the electronic excitation of an organic molecule. The stratospheric ozone layer prevents UV light of less than 290 nm from reaching the earth's surface. Therefore, only light at wavelengths between 290 and 750 nm can result in photochemical transformations in the environment. A conservative approach to estimating a photochemical degradation rate is to assume that degradation will occur in proportion to the amount of light wavelengths >290 nm absorbed by the molecule.

Hydrocarbons, C12-C15, n-alkanes, isoalkanes, cyclics < 2% aromatics (D90) contains hydrocarbon molecules that absorb UV light below 290 nm, a range of UV light that does not reach the earth's surface. Therefore, this substance does not have the potential to undergo photolysis in water and soil, and this fate process will not contribute to a measurable degradative loss of this substance from the environment.

Phototransformation in soil

The direct photolysis of an organic molecule occurs when it absorbs sufficient light energy to result in a structural transformation. The absorption of light in the ultra violet (UV)-visible range, 110-750 nm, can result in the electronic excitation of an organic molecule. The stratospheric ozone layer prevents UV light of less than 290 nm from reaching the earth's surface. Therefore, only light at wavelengths between 290 and 750 nm can result in photochemical transformations in the environment.

A conservative approach to estimating a photochemical degradation rate is to assume that degradation will occur in proportion to the amount of light wavelengths >290 nm absorbed by the molecule. Hydrocarbons, C12-C15, n-alkanes, isoalkanes, cyclics, < 2% aromatics (D90) contains hydrocarbon molecules that absorb UV light below 290 nm, a range of UV light that does not reach the earth's surface. Therefore, this substance does not have the potential to undergo photolysis in water and soil, and this fate process will not contribute to a measurable degradative loss of this substance from the environment.

Biodegradation in water: screening tests

No studies have been performed to determine the biodegradation in water of Hydrocarbons, C12-C15, n-alkanes, isoalkanes, cyclics, < 2% aromatics, however data are available for substances in the same carbon range.

Hydrocarbons, C12-C16, n-alkanes, isoalkanes, cyclics <2% aromatics, biodegraded to an extent of 68% after 28 days and 69% after 31 days in an OECD 301F test. The data indicate that Hydrocarbons, C12-C16, n-alkanes, isoalkanes, cyclics, <2% aromatics is rapidly biodegradable, readily biodegradable, and not expected to persist in the environment under aerobic conditions.

Hydrocarbons, C12-C16, n-alkanes, isoalkanes, cyclics, <2% aromatics (source) is a structural analogue of the registered substance Hydrocarbon C12-C15 n-alkanes, isoalkanes, cyclics, < 2% aromatics (D90) (target). The conclusion of readily biodegradable is read across from the source substance to the target substance.

Biodegradation in water and sediment: simulation tests

In accordance with REACH Annex IX column 2 exemption, the simulation testing in water and sediment does not need to be conducted as Hydrocarbons, C12-C15, n-alkanes, isoalkanes, cyclics, < 2% aromatics (D90) is considered to be readily biodegradable based on read across of reliable data from another hydrocarbon substances in the relevant carbon number range (structural analogue).

Biodegradation in soil

In accordance with REACH Annex IX column 2 exemption, the simulation testing in water and sediment does not need to be conducted as Hydrocarbons, C12-C15, n-alkanes, isoalkanes, cyclics, < 2% aromatics (D90) is considered to be readily biodegradable based on read across of reliable data from another hydrocarbon substances in the relevant carbon number range (structural analogue).

Bioaccumulation: aquatic/sediment

This endpoint has been calculated for representative hydrocarbon structures including the constituents of Hydrocarbons, C12-C15, n-alkanes, isoalkanes, cyclics, < 2% aromatics using the BCFWIN v2.16 model within EPISuite 3.12 as input to the hydrocarbon block method incorporated into the PETRORISK model. The predicted BCFs for hydrocarbons are generally overly conservative since biotransformation is not quantitatively taken into account. Therefore, indirect exposure and resulting risk estimates predicted by PETRORISK are likely to be overestimated.

Bioaccumulation: terrestrial

The substance is a hydrocarbon UVCB. Standard bioaccumulation studies for this endpoint are intended for monoconstituent substances and are not applicable for this complex substance.

Adsorption / desorption:

Hydrocarbons, C12-C15, n-alkanes, isoalkanes, cyclics, < 2% aromatics (D90) is a petroleum UVCB. Standard tests for this endpoint are intended for single substances and are not appropriate for this complex substance. However, this endpoint is characterized using quantitative structure property relationships for representative hydrocarbon structures that comprise the hydrocarbon blocks used to assess the environmental risk of these substances with the PETRORISK model (see Product Library  in PETRORISK spreadsheet attached to Section 13).

Volatilisation:

Volatilisation is dependent on Henry's Constant (HC) which is not applicable to complex substances. However, HC values for representative structures are included in the PETRORISK spreadsheet attached to IUCLID Section 13. The HC of the constituents of Hydrocarbons, C12-C15, n-alkanes, isoalkanes, cyclics, < 2% aromatics ranges from 0.02 to 53.15.

Distribution modelling:

The distribution of Hydrocarbons, C12-C15, n-alkanes, isoalkanes, cyclics, < 2% aromatics in the environmental compartments, air, water, soil, and sediment, has been calculated using the PETRORISK Model, version 7.04.Computer modelling is an accepted method for estimating the environmental distribution of chemicals. Distribution modelling results are included in the 'Multimedia distribution modelling results' tab in the PETRORISK spreadsheet attached to IUCLID section 13.

Based on the regional scale exposure assessment, the multimedia distribution of Hydrocarbons, C12-C15, n-alkanes, isoalkanes, cyclics, < 2% aromatics is 2.5% to air, 1.6% to water, 11 % to soil and 85 % to sediment.