Registration Dossier

Ecotoxicological information

Toxicity to microorganisms

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
toxicity to microorganisms, other
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
data from handbook or collection of data
Remarks:
Experimental data of test chemical
Justification for type of information:
Experimental data of test chemical is from collection of data
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Qualifier:
according to
Guideline:
other: Refer below principle
Principles of method if other than guideline:
WoE was prepared for the determination of toxicity range of chemical on the growth of different microorganisms.
GLP compliance:
no
Analytical monitoring:
no
Vehicle:
yes
Remarks:
<=0.75 % of Sulfinyl bis(methane)
Test organisms (species):
other: activated sludge, Tetrahymena pyriformis
Details on inoculum:
WoE 1: Type : mixed population of aquatic microorganism (activated sludge)
Origin :aeration tank of a waste water treatment plant treating predominantly domestic sewage
Pretreatment : aeration of the activated sludge;daily feed with synthetic medium

WoE 4: strain GL-C
Test type:
static
Water media type:
freshwater
Total exposure duration:
3 h
Remarks on exposure duration:
48 hrs in 3rd and 4th study
Post exposure observation period:
Incubation time : 3 hours with permanent aeration
Test temperature:
27 and 35 deg C
pH:
5.0 and 8.6
Nominal and measured concentrations:
WoE 2: Test concentration (mg/l) : 10,18,32,56,100
Test concentration of the activated sludge : 6 g/l
Test substance concentration in physico-chemical oxygen consumption control (mg/l) : 100
Type of application : solution :1 g/l
Details on test conditions:
WoE 2: The respiration rate of an activated sludge is measured after a contact time of 3 hours.The respiration rate of the same activated sludge in the presence of various concentration of the test substance under otherwise identical conditions is also measured.The inhibitory effect of the test substance at a particular concentration is expressed as a percetage of the mean respiration rates of two controls.An EC50 value is calculated from determinations at different concentrations.

WoE 3: - No. of vessels per concentration (replicates): >=3 Replicates

WoE 4: Cultures were reared in 50 mL of a semi defined medium in 250-mL Erlenmeyer flasks. Definitive test replicates consisted of a minimum of 5 different concentrations of each test material. Duplicate flasks were inoculated to an initial density of 2500 cells/ mL with log-growth phase ciliates. Following 40 h of incubation at 27 deg C, population density was measured spectrophotometrically and 50% effect levels were determined.
Reference substance (positive control):
yes
Remarks:
WoE 2: 3.5 -dichlorophenol
Key result
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
71 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
other: respiration inhibition
Remarks on result:
other: WoE 2
Duration:
48 h
Dose descriptor:
IC50
Effect conc.:
161.27 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
other: Population growth rate inhibition
Remarks on result:
other: WoE 3
Duration:
48 h
Dose descriptor:
other: IGC50
Effect conc.:
377 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
growth inhibition
Remarks on result:
other: WoE 4
Reported statistics and error estimates:
WoE 2: The EC values are determined by statistical methods (Probit analysis)
Validity criteria fulfilled:
not specified
Conclusions:
Test chemical has showed 50% respiration inhibition of activated sludge at a concentration of 71 mg/l.
The Inhibition concentration (IC50) of test material in tetrahymena pyriformis was observed to be 161.27 mg/L on the basis of population growth rate effect in a 48 hours of exposure.
The impairment growth concentration (IGC50) of test chemical in microorganism [Tetrahymena pyriformis] in a 48 hr study on the basis of growth inhibition effect using a short-term, static protocol was datarmine to be 377 mg/L.
Thus on the basis of above studies, chemical consider to be nontoxic.
Executive summary:

Various studies available for the test chemical were reviewed to determine the toxic nature of test chemical on the growth and other activity of microorganisms. The studies are as mentioned below:

 

In the first study from experimental report study performed to assess the toxicity of test chemical to bacteria.The study was conducted in accordance with ISO 8192. The activated sludge was exposed to test substance at different concentrations.The respiration rate of each mixture was determined after aeration period of 3 hours. Test chemical showed 50% respiration inhibition of activated sludge at a test substance concentration of 71 mg/l (EC50 =71 mg/l).

First study was supported by the second study from peer reviewed journal. A test was developed using Tetrahymena pyriformis in order to determine the toxicity of test material. The concentration of the chemical, at which the inhibition of test organism i.e T. pyriformis was observed (IC50), was determined. The Inhibition concentration (IC50) of test material in tetrahymena pyriformis was observed to be 161.27 mg/L on the basis of population growth rate effect in a 48 hours of exposure.

Similarly a short-term, static protocol using the common freshwater ciliate Tetrahymena pyriformis (strain GL-C) was reported. The 50% impairment growth concentration (IGC 50) is the endpoint of choice. Cultures were reared in 50 mL of a semi defined medium in 250-mL Erlenmeyer flasks. Definitive test replicates consisted of a minimum of 5 different concentrations of each test material. Duplicate flasks were inoculated to an initial density of 2500 cells/ mL with log-growth phase ciliates. Following 40 h of incubation at 27 deg C, population density was measured spectrophotometrically and 50% effect levels were determined.The impairment growth concentration (IGC50) of test chemical in microorganism [Tetrahymena pyriformis] in a 48 hr study on the basis of growth inhibition effect using a short-term, static protocol was datarmine to be 377 mg/L.

Thus on the basis of above studies, chemical consider to be nontoxic.

Description of key information

WoE 2: Test chemical has showed 50% respiration inhibition of activated sludge at a concentration of 71 mg/l.

WoE 3: The Inhibition concentration (IC50) of test material in tetrahymena pyriformis was observed to be 161.27 mg/L on the basis of population growth rate effect in a 48 hours of exposure.

WoE 3: The impairment growth concentration (IGC50) of test chemical in microorganism [Tetrahymena pyriformis] in a 48 hr study on the basis of growth inhibition effect using a short-term, static protocol was datarmine to be 377 mg/L.

Thus on the basis of above studies, chemical consider to be nontoxic.

Key value for chemical safety assessment

EC50 for microorganisms:
71 mg/L

Additional information

Various studies available for the test chemical were reviewed to determine the toxic nature of test chemical on the growth and other activity of microorganisms. The studies are as mentioned below:

 

In the first study from experimental reportstudy performed to assess the toxicity of test chemical to bacteria.The study was conducted in accordance with ISO 8192. The activated sludge was exposed to test substance at different concentrations.The respiration rate of each mixture was determined after aeration period of 3 hours. Test chemical showed 50% respiration inhibition of activated sludge at a test substance concentration of 71 mg/l (EC50 =71 mg/l).

First study was supported by the second study from peer reviewed journal. A test was developed using Tetrahymena pyriformis in order to determine the toxicity of test material. The concentration of the chemical, at which the inhibition of test organism i.e T. pyriformis was observed (IC50), was determined. The Inhibition concentration (IC50) of test material in tetrahymena pyriformis was observed to be 161.27 mg/L on the basis of population growth rate effect in a 48 hours of exposure.

Similarly a short-term, static protocol using the common freshwater ciliate Tetrahymena pyriformis (strain GL-C) was reported. The 50% impairment growth concentration (IGC 50) is the endpoint of choice. Cultures were reared in 50 mL of a semi defined medium in 250-mL Erlenmeyer flasks. Definitive test replicates consisted of a minimum of 5 different concentrations of each test material. Duplicate flasks were inoculated to an initial density of 2500 cells/ mL with log-growth phase ciliates. Following 40 h of incubation at 27 deg C, population density was measured spectrophotometrically and 50% effect levels were determined.The impairment growth concentration (IGC50) of test chemical in microorganism [Tetrahymena pyriformis] in a 48 hr study on the basis of growth inhibition effect using a short-term, static protocol was datarmine to be 377 mg/L.

Thus on the basis of above studies, chemical consider to be nontoxic.