pymetrozine (ISO); (E)-4,5-dihydro-6-methyl-4-(3-pyridylmethyleneamino)-1,2,4-triazin-3(2H)-one

Phototransformation in air

Link to relevant study record(s)

Reference

Endpoint:

phototransformation in air

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

08 May 1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

DT50:

27.35 h

Test condition:

calculated with 1.5E6 OH-radicals/cm3 and a 12-hour day

Remarks on result:

other: recalculated oxidation rate for triazinone fragment

DT50:

4.14 h

Test condition:

calculated with 1.5E6 OH-radicals/cm3 and a 12-hour day

Reaction with:

OH radicals

Rate constant:

0 cm³ molecule-1 s-1

Remarks on result:

other: recalculated oxidation rate for triazinone fragment

Reaction with:

OH radicals

Rate constant:

0 cm³ molecule-1 s-1

In the case of unknown structural elements, the estimation accuracy decreases in the same way as the chemical similarity of the used fragments in comparison with the real structure decreases. For the chemical class of triazinones, where the substance belongs to, so far no measured rate values are known. Based on the well experienced chemical reactivity in the sequence amine - amide - urea it is supposed, that the fragments taken to represent these functional groups overestimate the reactivity against an OH radical reaction.

The estimated halflife (Atkinson method) of the test substance in the atmosphere (by hydroxyl radical oxidation) is between 4 and 28 hours.

Conclusions:

The estimated halflife (Atkinson method) of the test substance in the atmosphere (by hydroxyl radical oxidation) is between 4 and 28 hours.

Executive summary:

In a calculation using the Atmospheric Oxidation Program v 1.55a based on the Atkinson method, the estimated halflife (Atkinson method) of the test substance in the atmosphere (by hydroxyl radical oxidation) was estimated to be between 4 and 28 hours. The latter value was derived using a recalculated rate for the oxidation rate of the triazinone, which was not included in the known fragments of the software used.

Description of key information

The estimated half-life of the test substance in the atmosphere is between 4 and 28 hours (AOPWIN QSAR prediction), Stamm 1998.

Information on this endpoint is not part of Annex VIII data requirements; all included studies are marked as supporting information and considered in the CSA.