Registration Dossier

Administrative data

Endpoint:
phototransformation in water
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996

Materials and methods

Study type:
direct photolysis
Test guideline
Qualifier:
according to guideline
Guideline:
other: US FDA Technical Assistance Document Guideline 3.10 Photodegrataion 1987
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
Pyridine-2-thiol 1-oxide, sodium salt
EC Number:
223-296-5
EC Name:
Pyridine-2-thiol 1-oxide, sodium salt
Cas Number:
3811-73-2
Molecular formula:
C5H5NOS.Na
IUPAC Name:
sodium (1-oxo-1lambda5-pyridin-2-yl)sulfanide
Details on test material:
- Analytical purity: 40% aqueous solution
- Lot/batch No.: 64/95

Study design

Radiolabelling:
no
Analytical method:
other: Micellar electrokinetic capillary chromatography with UV detector
Details on sampling:
5, 10, 15, 20 minutes for pH 5 and pH 7
15, 30, 45, 60 minutes for pH 9
Light source:
Xenon lamp
Details on light source:
Simulated sunlight by Heraeus Suntest CPS system. Xenon burner.
Details on test conditions:
Temperature: 16 to 21 °C.
pH: 5; 7; and 9
Duration of test at given test condition
Duration:
60 min
Temp.:
18 °C
Initial conc. measured:
10 mg/L
Reference substance:
yes
Remarks:
p-nitroanisole

Results and discussion

% Degradationopen allclose all
% Degr.:
84
Sampling time:
10 min
Test condition:
pH5
% Degr.:
89
Sampling time:
15 min
Test condition:
pH5
% Degr.:
90
Sampling time:
20 min
Test condition:
pH5
% Degr.:
85
Sampling time:
10 min
Test condition:
pH7
% Degr.:
90
Sampling time:
15 min
Test condition:
pH7
% Degr.:
96
Sampling time:
20 min
Test condition:
pH7
% Degr.:
100
Sampling time:
5 min
Test condition:
pH9
% Degr.:
100
Sampling time:
20 min
Test condition:
pH9
Predicted environmental photolytic half-life:
<10 minutes at pH 5 and pH 7
<15 minutes at pH 9
Transformation products:
not measured
Details on results:
Concentration of sodium pyrithione in pH9 samples was below the limit of detection at all time points
Kcp at pH5 0.12-0.18
Kcp at pH7 0.15-0.19

Applicant's summary and conclusion

Conclusions:
Fast photodegradation was detected so that only estimated of the half life could be obtained. Half lifes of <10 minutes for pH5 and pH7 and <15 minutes for pH 9 (corrected for UK midsummer sunlight) were determined. The information contained within this robust summary document comes from studies which are in the ownership of Arch Chemicals Inc. and which are protected in several regions globally. This information may not be used for any purpose other than in support of the Chemical safety Report submitted by Arch Chemicals Inc. under Regulation EC 1907/2006.