Acetic acid, oxo-, sodium salt, reaction products with ethylenediamine and phenol, iron sodium salts

Phototransformation in water

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

phototransformation in water

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1996-05-20 to 1996-08-22

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Study type:

direct photolysis

Qualifier:

according to guideline

Guideline:

OECD Guideline draft (Phototransformation of Chemicals in Water - Direct and Indirect Photolysis)

Version / remarks:

1995

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report): FeEDDHMANa
- Physical state: red, brown powder
- Analytical purity: 65 % based of Certiface of Analysis
- Lot/batch No.: 954243
- Storage condition of test material: At room temperature, dry in the dark

Radiolabelling:

no

Analytical method:

high-performance liquid chromatography

Details on sampling:

Samples of <= 2 mL were taken. Each test solution was diluted 50 times with 15/85/0.4 (v/v/w) methanol/Milli-Q water/ammonium acetate, prior to analysis.

Buffers:

A 0.05 M phosphate buffer pH7 of potassium dihydrogenphosphate/sodium hydroxide was prepared in double distilled water. To exclude oxygen, nitrogen gas was bubbled through the buffer solution for approx. 10 min.

Light source:

Xenon lamp

Light spectrum: wavelength in nm:

> 290 - < 500

Details on light source:

The determination of the absolute distribution of the light intensity entering the reaction cell was based on an actinometric measurement using the potassium ferrioxalate actinometer. This actinometer system has a quantum yield of 1.211 molecules ferric(II) formed per photon absorbed, which can be considered to be constant in the wavelength range of 290 to 500 nm and independent of temperature and light intensity. The actinometric measurement was performed in the same reaction vessel and under the same conditions as the test solution. After a lightning period of exactiy 1 minute, the formed amount of ferrous(II) ion was determined via the spectrophotometric determination of its phenantroline complex at 510 nm. The ferric(III) ion apparently forms only a weak complex with phenantroline which is transparent at 510 nm. The formed ferrous(II) in the photo reactor (ΔN in molecules per second) gave the number of photons absorbed per second in the actinometer solution i.e. the number of photons emitted per second by the test apparatus in the wavelength range of 290 - 500 nm going through the quartz top and actually reaching the test sample.

Duration:

98.7 h

Temp.:

25 °C

Initial conc. measured:

0.87 g/L

Reference substance:

no

Dark controls:

yes

Key result

DT50:

40.66 h

Test condition:

for component A (retention time 6.5)

Key result

DT50:

35.4 h

Test condition:

for component B (retention time 19.9)

Transformation products:

no

Validity criteria fulfilled:

yes

Conclusions:

The half-life time for phototransformation of FeEDDHMANa at 25 +/- 3 °C is determined to be 40.66 and 35.4 hours for the two major compartments of this UVCB substance, at a light intensity of 4.86E20 photons/second in the wavelength range of 290 - 500 nm.

Executive summary:

The degradation of FeEDDHMANa in water as a result of direct photo-transformation (photolysis) was investigated according to the OECD Draft guidance document:"Direct Phototransformation of Chemicals in water". Chemical analysis of FeEDDHMANa resulted not in one peak, but in 4 peaks (2 major peaks at approximately t = 6.5 and t = 19.9 minutes, respectively and two minor peaks at approximately t = 5.5 and t = 18.9 minutes, respectively). So probably, the test substance consists of at least 4 components. For practical reasons, the photochemic degradation of the 2 major components (component A and B) was determined. The half-life time for phototransformation of FeEDDHMANa at 25 +/- 3 °C is determined to be 40.66 and 35.4 hours for the two major compartments of this UVCB substance, at a light intensity of 4.86E20 photons/second in the wavelength range of 290 - 500 nm.

Reference 2

Endpoint:

phototransformation in water

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

For justification of read across see section 13.

Reason / purpose for cross-reference:

read-across source

Key result

DT50:

40.66 h

Test condition:

for component A (retention time 6.5)

Key result

DT50:

35.4 h

Test condition:

for component B (retention time 19.9)

Description of key information

DT50 = 35.4 - 40.66 h at 25 °C and a light intensity of 4.86E20 photons/second in the wavelength range of 290 - 500 nm (read across)

Key value for chemical safety assessment

Half-life in water:

40.66 h

Additional information

Since no studies are available on phototransformation of Acetic acid, oxo-, sodium salt, reaction products with ethylenediamine and phenol, iron sodium salts (CAS No. 84539-55-9) in water, the assessment was based on a study conducted with source substance N,N'-Bis(2-hydroxy-4-methylphenyl)ethylenediamine diacetic acid, ferric-sodium complex (CAS No. 149057-66-9) in a read across approach. This is in accordance with Regulation (EC) No. 1907/2006, Annex XI, 1.5. Grouping of substance and read across approach. Further justification for suitability of read across between target and source substance is given in the read across justification document attached to chapter 13.

The key study was performed according to an OECD Guideline draft (Phototransformation of Chemicals in Water - Direct and Indirect Photolysis) from 1995 and GLP (Akzo 1996). The half-life time for phototransformation of FeEDDHMANa at 25 ±3 °C is determined to be 40.66 and 35.4 hours for the two major compartments of this UVCB substance, at a light intensity of 4.86E20 photons/second in the wavelength range of 290 - 500 nm. Thus, the substance is considered to be quickly phototranformed in the aqueous environment. Based on the suitability of the read across approach, this assumption is also considered to be true for Acetic acid, oxo-, sodium salt, reaction products with ethylenediamine and phenol, iron sodium salts.