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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

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Environmental fate & pathways

Phototransformation in air

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Description of key information

QSAR estimations are available for the 3 main constituents of DAPD.
1) Supporting study (QSAR): EpiWeb estimation for R-59_12h (CAS 74-31-7) (0 methyl groups)
2) Supporting study (QSAR): EpiWeb estimation for R-1679_12h (CAS 27173-16-6) (1 methyl group)
3) Supporting study (QSAR): EpiWeb estimation for R-898_12h (CAS 15017-02-4) (2 methyl groups)

Key value for chemical safety assessment

Half-life in air:
0.64 h

Additional information

The phototransformation rate in air was estimated with the aid of a QSAR model (EpiWeb) since no actual data are available for the substance of concern. This model was run for the 3 main constituents of DAPD.

The Atmospheric Oxidation Program for Microsoft Windows (AOPWIN) estimates the rate constant for the atmospheric, gas-phase reaction between photochemically produced hydroxyl radicals and organic chemicals.The rate constants estimated by the program are then used to calculate atmospheric half-lives for organic compounds based upon average atmospheric concentrations of hydroxyl radicals.

The default settings for 12 -hour daylight hydroxyl radical concentration of 1.5 *106 radicals/cm3 was used.

The DT50 (at 25°C) was similar for all 3 constituents, namely 0.64 hrs, the overall degradation rate constant (OH) was 200.2720 * 10-12 cm3/molecule-sec.