Pyridine-2-thiol 1-oxide, sodium salt

Phototransformation in water

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

Test material information

Constituent 1

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-1λ⁵-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

% Degradation

% Degradation 1

% Degr.:

84

Sampling time:

10 min

Test condition:

pH5

% Degradation 2

% Degr.:

89

Sampling time:

15 min

Test condition:

pH5

% Degradation 3

% Degr.:

90

Sampling time:

20 min

Test condition:

pH5

% Degradation 4

% Degr.:

85

Sampling time:

10 min

Test condition:

pH7

% Degradation 5

% Degr.:

90

Sampling time:

15 min

Test condition:

pH7

% Degradation 6

% Degr.:

96

Sampling time:

20 min

Test condition:

pH7

% Degradation 7

% Degr.:

100

Sampling time:

5 min

Test condition:

pH9

% Degradation 8

% 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.