Registration Dossier

Administrative data

Endpoint:
toxicity to terrestrial arthropods: long-term
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:
2009

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
ISO 11267 (Inhibition of Reproduction of Collembola by Soil Pollutants)
GLP compliance:
yes
Application method:
soil

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:
Batch No: AA270488EXA002
Purity: 40.7%
CoA ref: 495118
Physical state: dark yellow liquid
Density: 1.218g/ml

Sampling and analysis

Details on sampling:
After 28 days the content of test vessels was suspended in water. Adults were counted visually, juveniles were counted under a microscope.

Test substrate

Details on preparation and application of test substrate:
Artificial soil according to ISO 11267:
10% sphagnum peat
20% Kaolin clay
0.6% CaCO3
69.4% fine quartz sand
MWHC: 57%
Stock solution concentration: 13.335mg/g (2667mg sodium pyrion 40% made upt ot 200g with water)

Test organisms

Test organisms (species):
Folsomia candida
Animal group:
Collembola (soil-dwelling springtail)
Details on test organisms:
Source: In-house culture
Age: 10-12 days
Food: 2mg dry yeast on days 0 and 14

Study design

Study type:
laboratory study
Total exposure duration:
28 d

Test conditions

Test temperature:
19-21 degrees C
pH (if soil or dung study):
5.8-6.0
Humidity:
27.5-30.8%
Photoperiod and lighting:
Photoperiod: 16l:8d
Details on test conditions:
organisms/concentration: 50 (5 replicates of 10 organisms)
vessel: 100ml glass filled with approx 30g soil
Nominal and measured concentrations:
Nominal: 0, 250, 500, 1000, 2000, 4000 mg/kg dw
Reference substance (positive control):
yes
Remarks:
Betosip (phenmidipham 157g/l)

Results and discussion

Effect concentrationsopen allclose all
Duration:
28 h
Dose descriptor:
NOEC
Effect conc.:
500 mg/kg soil dw
Basis for effect:
mortality
Duration:
28 h
Dose descriptor:
LC50
Effect conc.:
822 mg/kg soil dw
Basis for effect:
mortality
Duration:
28 h
Dose descriptor:
NOEC
Effect conc.:
250 mg/kg soil dw
Basis for effect:
reproduction
Duration:
28 h
Dose descriptor:
EC50
Effect conc.:
670 mg/kg soil dw
Basis for effect:
reproduction
Details on results:
See table below
Results with reference substance (positive control):
Statistically significant effect on reproduction at >101 mg/ kg dw, mortality at > 180mg/kg dw

Any other information on results incl. tables

Mortality after 28 days

 Conc (mg/kg) Mean No. survivng adults  % mortality 
 control 8.6  14 
 250 8.4  16 
 500 7.4  26 
 1000  5.0 50 
 2000 1.8  8.2 
 4000 100 

Reproduction

 Conc (mg/kg)  Mean No. juveniles  % control
 control 452  n/a 
 250 466  103 
 500 361  80 
 1000 56  12       
 2000
 4000

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
A mortality of up to 100% was observed in the test item treated groups. Up to the concentration of 500 mg/kg dw the mortality was not statistically different compared to the control, where 14% of the Collembola died. Reproduct was not statistically significantly different compared to the control at the test concentration of 250 mg/kg dw. No behavioural abnormalities were observed in any treatment group. 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.
Executive summary:

In a 28 day reproduction test on Collembola (Folsomia candida), Sodium Pyrithione 40% caused no statistically signficant effects on mortality up to and including to the concentration of 500 mg/kg soil dry weight. The NOEC for mortality was determined to be 500 mg/kg soil dry weight. The LC50 was determined to be 822 mg/kg soil dry weight.

The reproduction values were not statistically different compared to the control at 250 mg/kg soil dry weight, which was therefore determined to be the NOEC for reproduction and to be the overall NOEC. The EC50 for reproduction was determined to be 670 mg/kg soil dry weight.