N-methylformanilide

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 from various test chemicals

Justification for type of information:

Experimental data of test chemical is from data from handbook or collection of data

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: Refer below principle

Principles of method if other than guideline:

WoE report is prepared based on toxicity to microorganisms study:
1 and 2nd

GLP compliance:

no

Analytical monitoring:

yes

Vehicle:

not specified

Test organisms (species):

other: 1. Tetrahymena pyriformis, 2. Pseudomonas putida

Details on inoculum:

1: strain GL-C

Test type:

static

Water media type:

freshwater

Total exposure duration:

48 h

Remarks on exposure duration:

16 hrs study was carried out in 2nd study

Test temperature:

1. 27 and 35 deg C
2. 26 degC

Details on test conditions:

1. 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.

2. The carrier of fluoranthene and its metabolites was a recommended mineral medium, composed for the test as follows (mg/l): NaNO3 ¼ 500; K2HPO4 ¼ 120; KH2PO4 ¼ 60; D(+) glucose monohydrate ¼ 2000; MgSO4 7H2O ¼ 200 and Iron(III) citrate ¼ 0.5. The pH was adjusted to 7.40.3.
In mineral medium; bacterial cultures incubated with title comp. in 26 deg C for ca. 16 h;turbidity of samples measured with spectrophotometer at 436 nm

Reference substance (positive control):

not specified

Key result

Duration:

48 h

Dose descriptor:

other: IGC50

Effect conc.:

377 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Remarks on result:

other: 1st study

Duration:

16 h

Dose descriptor:

EC50

Effect conc.:

223 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Remarks on result:

other: 2nd study

Validity criteria fulfilled:

no

Conclusions:

1. 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 determine to be 377 mg/L.
2. The effective concentration (EC50) value of test chemical in Pseudomonas putida in a 16 hr study on the basis of growth inhibition effect was observed to be 223 mg/L.
Thus based on the above effect observation, toxicity ranges from 223 mg/l to 377 mg/l.

Executive summary:

In different studies, the given test chemical, has been investigated for toxicity to microorganisms to a greater or lesser extent. The studies are summarized as below –

 

In the first key study a short -term, static protocol using the Tetrahymena pyriformis was reported for the test compound. 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 determine to be 377 mg/L.

 

Similar 16 hrs hrs toxicity study to microorganism was carried out for the test compound. Test conducted for 16 hrs under the static system. The effective concentration (EC50) value of test chemical in Pseudomonas putida in a 16 hr study on the basis of growth inhibition effect was observed to be 223 mg/L.

Thus based on the above effect observation, toxicity ranges from 223 mg/l to 377 mg/l.

Description of key information

1. 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 determine to be 377 mg/L.

2. The effective concentration (EC50) value of test chemical in Pseudomonas putida in a 16 hr study on the basis of growth inhibition effect was observed to be 223 mg/L.

Thus based on the above effect observation, toxicity ranges from 223 mg/l to 377 mg/l.

Key value for chemical safety assessment

EC50 for microorganisms:

377 mg/L

Additional information

In different studies, the given test chemical and structurally and functionally similar read across chemical, has been investigated for toxicity to microorganisms to a greater or lesser extent. The studies are summarized as below –

 

In the first key study a short -term, static protocol using the Tetrahymena pyriformis was reported for the test compound. 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 determine to be 377 mg/L.

 

Similar 16 hrs hrs toxicity study to microorganism was carried out for the test compound. Test conducted for 16 hrs under the static system. The effective concentration (EC50) value of test chemical in Pseudomonas putida in a 16 hr study on the basis of growth inhibition effect was observed to be 223 mg/L.

Thus based on the above effect observation, toxicity ranges from 223 mg/l to 377 mg/l.