Zeolite, silica rich, without aluminium, crystalline, synthetic, non fibrous

Toxicity to microorganisms

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. 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

Guideline:

DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Automatically generated during migration to IUCLID 6, no data available

IUPAC Name:

Automatically generated during migration to IUCLID 6, no data available

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 concentrations

Effect concentrations 1

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

Effect concentrations 2

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

Effect concentrations 3

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.