Benzyl isovalerate

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 of test chemical 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:

Aim of this study was to determine the effect of test chemical on the growth of microorganism. WoE was prepared.

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

other: Entosiphon sulcatum and Photobacterium phosphoreum

Details on inoculum:

WoE 2: 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:

72 h

Remarks on exposure duration:

30 min

Test temperature:

15 - 25°C

pH:

WoE 2: 6.9
WoE 3: 5-9

Details on test conditions:

WoE 2: 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

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

236 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Remarks on result:

other: WoE 2

Key result

Duration:

5 min

Dose descriptor:

EC50

Effect conc.:

3.02 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Viability and sensitivity of the bacteria

Remarks on result:

other: WoE3

Validity criteria fulfilled:

no

Conclusions:

WoE 2: Based on the growth inhibition of microorganisms, LOEC was determine to be 236 mg/l for test material in Entosiphon sulcatum when it was exposed for 72 h.
WoE 3: The 50% Effective concentration of test chemical to Photobacterium phosphoreum was determined to be 3.02 mg/l based on viability and sensitivity of bacteria.

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 experimental study from peer reviewed journal 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.

 

In the second study toxicity were measured. Photobacterium phosphoreum was test organism used to determine the toxicity of test material done by Microtox test method. The time period was 5 to 30 minute at 15 degree C and pH range from 5 to 9. After exposure, the 50% Effective concentration value for 1 test chemical to Photobacterium phosphoreum was determined to be 3.02 mg/l based on viability and sensitivity of bacteria. As the chemical were readily biodegradable thus degraded faster and consider to be nontoxic.

Description of key information

WoE 2: Based on the growth inhibition of microorganisms, LOEC was determine to be 236 mg/l for test material in Entosiphon sulcatum when it was exposed for 72 h.

WoE 3: The 50% Effective concentration of test chemical to Photobacterium phosphoreum was determined to be 3.02 mg/l based on viability and sensitivity of bacteria.

Key value for chemical safety assessment

EC50 for microorganisms:

236 mg/L

Additional information

Various studies available for the test chemical and structually and functionally similar read across chemicals 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 experimental study from peer reviewed journal 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.

 

In the second study toxicity were measured. Photobacterium phosphoreum was test organism used to determine the toxicity of test material done by Microtox test method. The time period was 5 to 30 minute at 15 degree C and pH range from 5 to 9. After exposure, the 50% Effective concentration value for 1 test chemical to Photobacterium phosphoreum was determined to be 3.02 mg/l based on viability and sensitivity of bacteria. As the chemical were readily biodegradable thus degraded faster and consider to be nontoxic.