Edetic acid

Phototransformation in air

Link to relevant study record(s)

Reference

Endpoint:

phototransformation in air

Type of information:

(Q)SAR

Adequacy of study:

key study

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

Justification for type of information:

QSAR prediction

Principles of method if other than guideline:

Calculation based on AOPWIN v1.92, Estimation Programs Interface Suite™ for Microsoft® Windows v 4.10. US EPA, United States Environmental Protection Agency, Washington, DC, USA.

GLP compliance:

no

Estimation method (if used):

PHOTOCHEMICAL REACTION WITH OH RADICALS
- Concentration of OH radicals: 0.5E+06 OH/cm3
- Degradation rate constant: 181E-12 cm3/mol*sec
- Temperature for which rate constant was calculated: 25 °C
- Computer programme: SRC AOP v1.92

Details on test conditions:

Sensitiser (for indirect photolysis): OH
Sensitiser concentration: 500000 molecule/cm³

Key result

DT50:

2.12 h

Test condition:

24-hr day; 0.5E6 OH/cm3

Transformation products:

not specified

For detailed description on the model and its applicability, see "Any other information on materials and methods incl. tables". The estimation is based on a 24 hour day.

Validity criteria fulfilled:

yes

Description of key information

After evaporation or exposure to the air, edetic acid will be rapidly degraded by photochemical processes.

Key value for chemical safety assessment

Half-life in air:

2.12 h

Degradation rate constant with OH radicals:

0 cm³ molecule-1 s-1

Additional information

No experimental studies investigating the phototransformation of edetic acid (CAS 60-00-4, EDTA) in air is available. A QSAR calculation using AOPWIN v1.92 indicates, that EDTA is susceptile to indirect photodegradation in air. The estimated half time for the reaction with OH-radicals is calculated to be 2.12 h (24h day; OH-concentration: 0.5E+06 OH/cm3). However, photodegradation is not considered to be an important environmental fate process since the substance is not expected to evaporate into the atmosphere due to the low vapor pressure of 2E-12 hPa at 20 °C.