Sulfapyridine

Toxicity to aquatic plants other than algae

Administrative data

Endpoint:

toxicity to aquatic plants other than algae

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2011

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: This is a publication result with a scientific method.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2011

Report date:

2011

Materials and methods

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Sulfapyridine

EC Number:

205-642-7

EC Name:

Sulfapyridine

Cas Number:

144-83-2

Molecular formula:

C11H11N3O2S

IUPAC Name:

4-amino-N-pyridin-2-ylbenzenesulfonamide

Details on test material:

no data

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
no data

Sampling and analysis

Analytical monitoring:

no

Details on sampling:

no data

Test solutions

Vehicle:

no

Details on test solutions:

no data

Test organisms

Test organisms (species):

Lemna minor

Details on test organisms:

The plants were grown in open Erlenmeyer flasks in sterilized Steinberg medium (pH 5.5 ± 0.2) in a climate chamber with a constant temperature of 25 ± 2 °C.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Test conditions

Hardness:

no data

Test temperature:

25 ± 2 °C

pH:

5.5± 0.2

Dissolved oxygen:

no data

Salinity:

no data

Nominal and measured concentrations:

no data

Details on test conditions:

To exclude pH effects on plant growth, pH was checked at the beginning and end of the test. The chamber was illuminated continuously with a maximum of 6000 lx. The assays were performed on six-well cell culture plates (Greiner Bio-One GmbH, Frickenhausen, Germany). The study was tested at least twice, with a minimum of six controls (pure Steinberg medium). The test started with one plant consisting of three duckweed fronds (leaves), and the measured endpoint was the inhibition of the growth rate determined by the frond area (mm2), which was calculated for the treated plants in relation to the untreated controls. The frond area was detected using a Scanalyzer from Lemnatec GmbH.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Dose descriptor:

EC50

Effect conc.:

0.46 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

no data

Results with reference substance (positive control):

no data

Reported statistics and error estimates:

The confidence interval (a = 0.05) of the EC50 value was calculated using the R language. The dose-response curve parameters and plots were obtained using the drift package (version 0.05-92) for the R language and environment for statistical computing (www.r-pro- ject.org) as well as SigmaPlot Version 10.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The EC50 was 0.46 mg/l.

Executive summary:

The growth inhibition assay with Lemna minor was performed according to a modified version of the test protocol described in detail by Drost et al. (2007). The EC₅₀ was 0.46 mg/l.