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Environmental fate & pathways

Phototransformation in soil

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Administrative data

Endpoint:
phototransformation in soil
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Data are from several peer reviewed sources.
Justification for type of information:
A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.
Cross-reference
Reason / purpose for cross-reference:
read-across source
Reference
Endpoint:
phototransformation in soil
Type of information:
other: Technical Discussion
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Data are from several peer reviewed sources.
Justification for type of information:
A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.
Reason / purpose for cross-reference:
read-across: supporting information
Qualifier:
no guideline followed
Principles of method if other than guideline:
Technical discussion
GLP compliance:
not specified
Conclusions:
The available weight of evidence demonstrate that "Hydrocarbons, C14-C20, aliphatics (<=2% aromatics)" do not absorb light within a range of 290 to 750 nm, the range in which photolysis ocurs. Therefore, direct photolysis will not contribute to the degradation of the substance in the terrestrial environment. Further testing is not required under Annex XI, section 1.2.
Executive summary:

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. This substance 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 soil, and this fate process will not contribute to a measurable degradative loss of this substance from the environment.

Data source

Referenceopen allclose all

Reference Type:
review article or handbook
Title:
Unnamed
Year:
1982
Reference Type:
publication
Title:
Unnamed
Year:
1977
Reference Type:
review article or handbook
Title:
Unnamed
Year:
2000

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Technical discussion
GLP compliance:
not specified

Test material

Constituent 1
Reference substance name:
C14-16 (even numbered) and C16 (branched) saturated and unsaturated aliphatic hydrocarbons
EC Number:
700-762-0
Molecular formula:
All molecules present in the mixture have the general molecular formula CnH2n for olefins or CnH2n+2 for the paraffin’s with n being an even number
IUPAC Name:
C14-16 (even numbered) and C16 (branched) saturated and unsaturated aliphatic hydrocarbons
Test material form:
liquid: viscous

Results and discussion

Applicant's summary and conclusion

Conclusions:
The available weight of evidence demonstrate that "Hydrocarbons, C14-C20, aliphatics (<=2% aromatics)" do not absorb light within a range of 290 to 750 nm, the range in which photolysis ocurs. Therefore, direct photolysis will not contribute to the degradation of the substance in the terrestrial environment. Further testing is not required under Annex XI, section 1.2.
Executive summary:

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. This substance 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 soil, and this fate process will not contribute to a measurable degradative loss of this substance from the environment.