Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional 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 hydrolyzable 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 C14-C20 Aliphatics (2-30% Aromatics) consist entirely of carbon and hydrogen and do not contain hydrolyzable groups. As such, they have a very low potential to hydrolyze. Therefore, this degradative process will not contribute to their removal from the environment.

Phototransformation in air:

Standard tests for atmospheric oxidation half-lives are intended for single substances and are not appropriate for these complex substances. 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 of the dossier).

Phototransformation in water and 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. C14-C20 Aliphatics (2-30% Aromatics) contain hydrocarbon molecules that absorb UV light below 290 nm, a range of UV light that does not reach the earth's surface. Therefore, these substances do not have the potential to undergo photolysis in water and soil, and this fate process will not contribute to a measurable degradative loss of these substances from the environment.

Biodegradation:

C14-C20 Aliphatics (2-30% Aromatics), multi-component substances, biodegraded to an extent of 61% after 28 days. The data support characterizing the test substance as rapidly biodegradable, readily biodegradable, not expected to persist in the environment under aerobic conditions. Although it did not meet the 10 -day window requirement, it is characterized as readily biodegradable because the criteria is not applied to multi-component substances when assessing their ready biodegradability.

Adsorption / desorption:

C14-C20 Aliphatics (2-30% Aromatics) are hydrocarbon UVCBs. Standard tests for this endpoint are intended for single substances and are not appropriate for these complex substances. 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 of the dossier).

Distribution:

The distribution of C14-C20 Aliphatics (2-30% Aromatics) in the environmental compartments, air, water, soil, and sediment, has been calculated using the PETRORISK Model, version 5.2. Computer modeling is an accepted method for estimating the environmental distribution of chemicals. Distribution modeling results are included in the 'Multimedia distribution modeling results' tab in the PETRORISK spreadsheet attached to Section 13 of the dossier.