Registration Dossier

Ecotoxicological information

Toxicity to microorganisms

Currently viewing:

Administrative data

Endpoint:
toxicity to microorganisms
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
1991-08-09
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP guideline study, tested with the source substance CAS 1318-02-1. According to the ECHA Guidance Document "Practical guide 6: How to report read-across and categories (March 2010)", the reliability was changed from RL1 to RL2.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report Date:
1992

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Wessalith P
- Related CAS number: 1318-02-1
- Chemical name: Natriumaluminiumsilikat
- Framework: monoclinic
- Physical state: white crystalline powder
- Analytical purity: 80.6% active ingredient, 19.4% crystal water (source TNO), 79.8% active ingredient (source Degussa), respectively - two information sheets are given in the study report

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no
Details on test solutions:
As the test substance contained water insoluble particles, the centrifuged supernatants of each concentration were used for testing.

Test organisms

Test organisms (species):
Pseudomonas putida

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
16 h

Test conditions

Hardness:
no data
Test temperature:
21+/-0.5 °C
pH:
pH in the control at test start was 7.1, at test end 6.9 to 7.4 for neutralized background samples, and 7.1 to 10.2 for alkaline background samples, increasing with concentration.
Dissolved oxygen:
no data
Nominal and measured concentrations:
0, 0.1, 0.3, 0.10, 0.33, 1.0, 3.3, 5.5 and 10 g/L of the test substance
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
16 h
Dose descriptor:
EC10
Effect conc.:
330 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Remarks:
eluate
Basis for effect:
growth inhibition
Duration:
16 h
Dose descriptor:
EC50
Effect conc.:
950 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Remarks:
eluate
Basis for effect:
growth inhibition
Duration:
16 h
Dose descriptor:
EC50
Effect conc.:
1 550 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Remarks:
eluate
Basis for effect:
growth inhibition
Remarks on result:
other: alkalic

Any other information on results incl. tables

The EC10 was estimated to 0.33 g/L for both samples. The EC50 value for neutralized samples was found to correspond to 0.95 g/L (95% confidence interval of 0.57-1.59 g/L), for alkaline samples 1.55 g/L (95% confidence interval of 0.53-4.54 g/L).

The bacterial growth generally resulted in a decrease of the pH of the medium. The highest decrease was found with a neutralized test substance (0.33 g/L, pH 4.9). The inhibition was also stronger after neutralization, indicating that at least a part of the inhibition was caused by this decrease.

Applicant's summary and conclusion