Registration Dossier
Registration Dossier
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EC number: 203-398-6 | CAS number: 106-44-5
Phototransformation in water
Administrative data
Link to relevant study record(s)
- Endpoint:
- phototransformation in water
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Reliability:
- 2 (reliable with restrictions)
- Rationale for reliability incl. deficiencies:
- study well documented, meets generally accepted scientific principles, acceptable for assessment
- Study type:
- indirect photolysis
- Principles of method if other than guideline:
- rose bengal used as sensitizer for formation of singlet oxygen
- GLP compliance:
- not specified
- Analytical method:
- gas chromatography
- high-performance liquid chromatography
- Light source:
- other: Sylvania 650W Type DWY tungsten-halogen lamp
- Type of sensitiser:
- water with additives
- Details on sensitiser:
- rose bengal leading to formation of 1O2 at:
- Concentration of sensitiser:
- 4 other: 10E-14 molar
- Duration:
- 2 h
- Temp.:
- 19 °C
- % Degr.:
- 50
- Sampling time:
- 500 h
- Test condition:
- Indirect photolysis
- Validity criteria fulfilled:
- not specified
- Conclusions:
- In the hydrosphere the cresols are expected to undergo photolytical degradation because of the presence of the aromatic ring which acts as a chromophore. By irradiation of solutions of p-cresol in a merry-go-round reactor, with rose bengal as a sensitizer, a half-life of 21 d in surface water under noon summer sunlight and the latitude of Switzerland was estimated.
- Executive summary:
In the hydrosphere the cresols are expected to undergo photolytical degradation because of the presence of the aromatic ring which acts as a chromophore. By irradiation of solutions of p-cresol in a merry-go-round reactor, with rose bengal as a sensitizer, a half-life of 21 d in surface water under noon summer sunlight and the latitude of Switzerland was estimated.
Reference
INDIRECT PHOTOLYSIS due to 1O2 (singlet dioxygen)
- Rate constant: 1.1 E7 M-1 s-1 at pH 8.3
2.4 E7 M-1 s-1 at pH 8.8
1.6 E8 M-1 s-1 at pH 10
3.5 E8 M-1 s-1 at pH 11.5
- Half life t1/2: 500 h under noon summer sunlight(Switzerland) with 4E-14 M singlet oxygen
Description of key information
In the hydrosphere a half-life of 21 d in surface water under noon summer sunlight and the latitude of Switzerland was estimated for p-cresol.
Key value for chemical safety assessment
- Half-life in water:
- 21 d
Additional information
In the hydrosphere the cresols are expected to undergo photolytical degradation because of the presence of the aromatic ring which acts as a chromophore. By irradiation of solutions of p-cresol in a merry-go-round reactor, with rose bengal as a sensitizer, a half-life of 21 d in surface water under noon summer sunlight and the latitude of Switzerland was estimated.
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