Registration Dossier
Registration Dossier
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 204-616-2 | CAS number: 123-30-8
Phototransformation in air
Administrative data
Link to relevant study record(s)
Description of key information
The half-life of 4-aminophenol and its degradation rate constant in the presence of hydroxyl radicals were predicted by the use of quantitative structural activity relationship modeling, by the use of AOPWIN v1.92a, a model within the EPI Suite v4.00, validated QSAR model, part of OECD (Q)SAR Toolbox.
Key value for chemical safety assessment
- Half-life in air:
- 1.729 h
Additional information
The photolysis half-life and degradation rate constant of 4-aminophenol were estimated, based on QSAR modeling. The degradation constant with hydroxyl radicals was predicted to be74.2471 E-12cm3/molecule-1s-1. Assuming a hydroxyl radical concentration [-OH] of 1.5 x 106molecules/cm3and 12 hours of sunlight, the half-life was predicted as 1.729 hours (0.144 days).
The model User's Guide states that the 24-hour daylight average hydroxyl radical concentration may be more appropriate for chemicals that react more slowly (i. e.,> a few days). Since the modeling results indicate that 4-aminophenol is a fast-reacting chemical (with a half-life in the scale of hours), the estimated half-life associated with the default hydroxyl radical concentration with 12-hour daylight cycle (i. e., 1.729 hours) is considered the more appropriate of the two estimated half-life values.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
