Phenethyl butyrate

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 test chemical

Justification for type of information:

Experimental data is from 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 was prepared for the determination of toxicity of test chemical on the growth of microorganisms by involving WoE 2, WoE 3, WoE4

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

other: Tetrahymena pyriformis, Entosiphon sulcatum

Details on inoculum:

WoE 2: strain GL-C

WoE 3: To prepare feeding of the Entosiphon stock or preliminary cultures with bacteria, decant nutrient solution and suspend the bacterial centrifugate with a quantity of a 50% solution of stock solution I in sterile double-distilled water until the initial volume is reached again. Centrifuge and decant again this suspension as described above. Take up the centrifugate with a 50°/0 solution of stock solution I in sterile double-distilled water.

Test type:

static

Water media type:

freshwater

Total exposure duration:

48 h

Remarks on exposure duration:

72 hrs in WoE 3

Test temperature:

27 and 35 deg C
25°C

pH:

5-8.6
6.9

Details on test conditions:

WoE 2: 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.

WoE 3: For maintenance of the test strain of Entosiphon sulcatum continuously inoculate the expected required number of stock cultures at 72 h or 96 h intervals. For this, mix 8 ml of stock solution I and 8 ml of sterile double-distilled water in 300-ml Erlenmeyer flasks stoppered with metal caps and add 2 ml of a stock culture and 2 ml of the adjusted bacterial suspension for Entosiphon stock cultures. Store stock cultures at 25°C. Before inoculation control the flasks containing the stock cultures by means of an inverse microscope. Pretreatment of the bacteria used for feeding preliminary cultures of Entosiphon sulcatum does not differ from that of bacteria used for feeding the stock cultures. Keep preliminary cultures at 25°C over 72 h before using them for inoculation of the test cultures. Before inoculation control each flask containing the preliminary cultures by means of an inverse microscope.

Reference substance (positive control):

no

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: WoE 2

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

236 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Remarks on result:

other: WoE 3

Validity criteria fulfilled:

no

Conclusions:

WoE 2: 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.
WoE 3: The toxicity threshold (TT) of test material was determined to be 236 mg/l for Entosiphon sulcatum. Therefore LOEC was considered to be 236 mg/l for 72h in Entosiphon sulcatum.

Executive summary:

Various studies available for the test chemical from peer reviewed journals were reviewed to determine the toxic nature of the test chemical on the growth and other activity of of microorganism. The studies are as mention below:

In the first experimental study from peer reviewed journal 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.

First study was supported by the second study from peer reviewed journal. In toxicity to microorganism study for test material the biological effect was evaluated by using analogous methods of the cell multiplication inhibition test. For maintenance of the test strain of Entosiphon sulcatum continuously inoculate the expected required number of stock cultures at 72 h or 96 h intervals. For this, mix 8 ml of stock solution I and 8 ml of sterile double-distilled water in 300-ml Erlenmeyer flasks stoppered with metal caps and add 2 ml of a stock culture and 2 ml of the adjusted bacterial suspension for Entosiphon stock cultures. Store stock cultures at 25°C. Before inoculation control the flasks containing the stock cultures by means of an inverse microscope. Pretreatment of the bacteria used for feeding preliminary cultures of Entosiphon sulcatum does not differ from that of bacteria used for feeding the stock cultures. Keep preliminary cultures at 25°C over 72 h before using them for inoculation of the test cultures. Before inoculation control each flask containing the preliminary cultures by means of an inverse microscope. The toxicity threshold (TT) of test material was determined to be 236 mg/l for Entosiphon sulcatum. Therefore LOEC was considered to be 236 mg/l for 72h in Entosiphon sulcatum.

Thus on the basis of above both studies, toxicity of test chemical value ranges from 236 to 377 mg/l.

Description of key information

WoE 2: 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.

WoE 3: The toxicity threshold (TT) of test material was determined to be 236 mg/l for Entosiphon sulcatum. Therefore LOEC was considered to be 236 mg/l for 72h in Entosiphon sulcatum.

Key value for chemical safety assessment

EC50 for microorganisms:

377 mg/L

Additional information

Various studies available for the test chemical and structually and functionally similar read across chemical from peer reviewed journals were reviewed to determine the toxic nature of the test chemical on the growth and other activity of of microorganism. The studies are as mention below:

In the first experimental study from peer reviewed journal 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.

First study was supported by the second study from peer reviewed journal. In toxicity to microorganism study for test material the biological effect was evaluated by using analogous methods of the cell multiplication inhibition test. For maintenance of the test strain of Entosiphon sulcatum continuously inoculate the expected required number of stock cultures at 72 h or 96 h intervals. For this, mix 8 ml of stock solution I and 8 ml of sterile double-distilled water in 300-ml Erlenmeyer flasks stoppered with metal caps and add 2 ml of a stock culture and 2 ml of the adjusted bacterial suspension for Entosiphon stock cultures. Store stock cultures at 25°C. Before inoculation control the flasks containing the stock cultures by means of an inverse microscope. Pretreatment of the bacteria used for feeding preliminary cultures of Entosiphon sulcatum does not differ from that of bacteria used for feeding the stock cultures. Keep preliminary cultures at 25°C over 72 h before using them for inoculation of the test cultures. Before inoculation control each flask containing the preliminary cultures by means of an inverse microscope. The toxicity threshold (TT) of test material was determined to be 236 mg/l for Entosiphon sulcatum. Therefore LOEC was considered to be 236 mg/l for 72h in Entosiphon sulcatum.

Thus on the basis of above both studies, toxicity of test chemical value ranges from 236 to 377 mg/l.