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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Phototransformation in air

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Administrative data

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Description of key information

The half-life of hydroquinone in the atmosphere due to OH radical degradation is 16.58 hour (24-hr day; 0.5E6 OH/cm3) calculated using AopWin v1.92

Key value for chemical safety assessment

Half-life in air:
16.58 h

Additional information

No data is available. However, in order to be able to use CHESAR for the exposure assessment, a conclusion is provided for the CSA. So, the half-life of hydroquinone in the atmosphere due to OH radical degradation is calculated by QSAR model.


 


The EPISUITE model is relevant for this endpoint and therefore it is used to estimate the half-life value of hydroquinone as reported below.


Calculation using AopWin v.1.92 (via EPISUITE 4.00)


- Concentration of OH radicals: 500000 molecule/cm3, 24-hr day


- Degradation rate constant: 23.2235 E-12 cm3/molecule-sec


- Temperature for which rate constant was calculated: 25°C


According to this QSAR calculation, the half-life of hydroquinone in the atmosphere due to OH radical degradation is 16.58 hours (24-hr day; 0.5E6 OH/cm3).