Potassium nitrite

Toxicity to microorganisms

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 read across substances

Justification for type of information:

Data for the target chemical is summarized based on the structurally similar read across chemicals

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

WoE report is based on two toxicity to microorganism studies as-
WoE 2 and WoE 3.

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

other: WoE 2: activated sludge and WoE 3: Escherichia coli

Test type:

not specified

Water media type:

not specified

Total exposure duration:

96 h

Remarks on exposure duration:

WoE 2: 30 mins and WoE 3: 96 hr

Nominal and measured concentrations:

WoE 2: Highest tested concentration of 1800 mg/l
WoE 3: no data available

Reference substance (positive control):

not specified

Duration:

30 min

Dose descriptor:

EC0

Effect conc.:

1 800 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: WoE 2

Key result

Duration:

30 min

Dose descriptor:

EC50

Effect conc.:

> 1 800 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: WoE 2

Duration:

96 h

Dose descriptor:

other: growth inhibition threshold

Effect conc.:

180 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Remarks on result:

other: WoE 3

Key result

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

> 180 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Remarks on result:

other: WoE 3

Details on results:

WoE 2:
With proper introduction to adapted biological Purification plants are not disruptions to the dismantling activity of the activated sludge to be expected.
No respiratory inhibition of adapted activated sludge up to to the highest tested concentration of 1800 mg/l.

Validity criteria fulfilled:

not specified

Conclusions:

On the basis of the experimental studies of read across chemical and applying the weight of evidence approach and by evaluating the effect of test chemical on test organism, the EC50 value can be expected to be >180 mg/l.

Executive summary:

Data available of the read across chemicals has been reviewed to determine the effect of the test chemical on microorganisms. The studies are as mentioned below:

Toxicity to microorganisms study was carried out. Study was performed in accordance with the ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation) for 30 mins. Activated sludge (adapted) was used as a test inoculum. With proper introduction to adapted biological Purification plants are not disruptions to the dismantling activity of the activated sludge to be expected. No respiratory inhibition of adapted activated sludge up to to the highest tested concentration of 1800 mg/l. Thus, based on effect on total respiration of the test inoculum activated sludge, the 30 mins EC0 and EC50 value was determined to be 1800 and >1800 mg/l, respectively.

Another toxicity to microorganismsstudy was carried out. Study was performed using Escherichia coli as a test organism for a period of 96 hrs. Based on effect on growth inhibition of the test bacteria, growth inhibition threshold value was determined to be 180 mg/l. Thus, based on reviewer judgement, 96 hr EC50 value can be considered as >180 mg/l.

On the basis of the experimental studies of read across chemical and applying the weight of evidence approach and by evaluating the effect of test chemical on test organism, the EC50 value can be expected to be >180 mg/l.

Description of key information

On the basis of the experimental studies of read across chemical and applying the weight of evidence approach and by evaluating the effect of test chemical on test organism, the EC50 value can be expected to be >180 mg/l.

Key value for chemical safety assessment

EC50 for microorganisms:

180 mg/L

Additional information

Data available of the read across chemicals has been reviewed to determine the effect of the test chemical on microorganisms. The studies are as mentioned below:

 

Toxicity to microorganisms study was carried out. Study was performed in accordance with the ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation) for 30 mins. Activated sludge (adapted) was used as a test inoculum. With proper introduction to adapted biological Purification plants are not disruptions to the dismantling activity of the activated sludge to be expected. No respiratory inhibition of adapted activated sludge up to to the highest tested concentration of 1800 mg/l. Thus, based on effect on total respiration of the test inoculum activated sludge, the 30 mins EC0 and EC50 value was determined to be 1800 and >1800 mg/l, respectively.

 

Another toxicity to microorganisms study was carried out. Study was performed using Escherichia coli as a test organism for a period of 96 hrs. Based on effect on growth inhibition of the test bacteria, growth inhibition threshold value was determined to be 180 mg/l. Thus, based on reviewer judgement, 96 hr EC50 value can be considered as >180 mg/l.

 

On the basis of the experimental studies of read across chemical and applying the weight of evidence approach and by evaluating the effect of test chemical on test organism, the EC50 value can be expected to be >180 mg/l.