O-isobutyl ethylthiocarbamate

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

other: published data

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Isobutyl alcohol is reagents used in the manufacture of O-isobutyl ethylthiocarbamate (IBETC). Therefore, the health effects of Isobutyl alcohol need to be considered in the assessment of O-isobutyl ethylthiocarbamate (IBETC) .

Qualifier:

equivalent or similar to guideline

Guideline:

DIN 38412-27 (Pseudomonas putida Zellvermehrungshemmtest)

Deviations:

not specified

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

Before preparing the test cultures neutralize the pollutant solution having a known content in sterile double-distilled water to be tested by using the minimum volume of acid or alkaline solution. The initial concentration of the pollutant solution was not reported.

From this pollutant solution, prepare four parallel dilution series in 300 ml Erlenmeyer flasks, stoppered with cotton-lined plastic caps. Each of the dilutions contains 1 part v/v of polutant solution in 2E0 to 2E14 parts v/v mixture. Prepare the dilution series as follows: the first flask of each series contains 160 ml of pollutant solution at the start. Starting from this flask prepare the subsequent dilution steps at a constant dilution ratio by consistently mixing 80 ml of preliminary pollutant dilution and 80 ml double distilled water. Consequently, each flask contains 80 ml of culture liquid at the start. Make up each flask of the three dilution series to be inoculated to 100 ml by adding 5 ml each of stock solution I, 5 ml of stock solution II and 10 ml each of the prepared bacterial suspension from the preliminary culture having a known adjusted extinction value.

Test organisms (species):

Pseudomonas putida

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

16 h

Hardness:

not reported

Test temperature:

25ºC

pH:

not reported

Dissolved oxygen:

not reported

Salinity:

freshwater

Nominal and measured concentrations:

2E0 to 2E14 parts v/v mixture

Details on test conditions:

Type: aquatic

Reference substance (positive control):

no

Duration:

16 h

Dose descriptor:

other: TGK

Effect conc.:

280 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Validity criteria fulfilled:

not applicable

Conclusions:

A 16h Toxicity threshold concentration of 280 mg/l has been determined for growth inhibition effects to Pseudomonas putida of the test substance.
Isobutyl alcohol is reagents used in the manufacture of O-isobutyl ethylthiocarbamate (IBETC). Therefore, the health effects of Isobutyl alcohol need to be considered in the assessment of O-isobutyl ethylthiocarbamate (IBETC) .

Executive summary:

According to the ECHA Guidance on information requirements and chemical safety assessment, Chapter R.7b: Endpoint specific guidance section R.7.8.17.1 Laboratory data on toxicity on STP microorganisms, results of the cell multiplication inhibition test with P. putida can be used for calculation of the PNECmicro-organisms.

Description of key information

A 16h  Toxicity threshold concentration of 280 mg/l has been determined for growth inhibition effects to Pseudomonas putida of the test substance.

Key value for chemical safety assessment

EC50 for microorganisms:

280 mg/L

EC10 or NOEC for microorganisms:

56 mg/L