3,7-dimethyl-1-octyl acetate

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 micro-organism studies as-
2. and 3.

GLP compliance:

not specified

Analytical monitoring:

not specified

Details on sampling:

2. and 3. - Sampling method: Test chemical of known concentration was prepared in sterile double distilled water.

Vehicle:

not specified

Details on test solutions:

2. and 3.
- Preparation of inoculum for exposure: Keep stock cultures of the test strain, Pseudomonas putida, on the nutrient for stock and preliminary cultures in agar slant tubes. Prepare, for onward culturing of the test strain, new stock cultures at intervals of 1 week each. Incubate the inoculated stock cultures at 25"C for 24 h and keep in stock. stock.
If needed, prepare preliminary cultures from stock cultures on the above mentioned nutrient medium in agar slant tubes and incubate at 25°C for 24 h. Then, wash off the cell material with sterile saline. Determine the extinction of the monochromatic radiation at 436nm for a 10ram layer of the bacterial suspension by photoelectric measurement.

Test organisms (species):

Pseudomonas putida

Test type:

not specified

Water media type:

freshwater

Total exposure duration:

16 h

Test temperature:

25°C

Details on test conditions:

2. and 3.
TEST SYSTEM
- Test vessel: Erlenmeyer flask
- Type (delete if not applicable): Erlenmeyer flask stoppered with cottoned lined plastic caps was used for the study.
- Material, size, headspace, fill volume: 300 ml Erlenmeyer flask

GROWTH MEDIUM
- Standard medium used: No
- Detailed composition if non-standard medium was used: Composition of test medium contains sodium nitrate (1.06 g), dipotassium hydrogen phosphate (0.6 g), magnesium sulphate (0.2 g), D (+) glucose (10 g), Difco bacto agar (18 g), ferrous sulphate (0.001 g), and 1.5 ml trace element solution.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: After termination of the test period measure the extinction of the monochromatic radiation at 436 nm in a 10-mm layer in the inoculated dilution series.

Reference substance (positive control):

not specified

Duration:

16 h

Dose descriptor:

EC0

Effect conc.:

115 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Remarks on result:

other: 2. No effect were observed on multiplication of bacterial cells.

Duration:

16 h

Dose descriptor:

EC0

Effect conc.:

83 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Remarks on result:

other: 3. No effect were observed on multiplication of bacterial cells.

Validity criteria fulfilled:

not specified

Conclusions:

On the basis of the experimental studies of the structurally and functionally similar read across chemical and applying the weight of evidence approach, the EC0 value the test chemical on the growth rate, i.e, multiplication of the test organism Pseudomonas putida can be expected to be ranges from 83 to 115 mg/l, respectively.

Executive summary:

Data available for the structurally and functionally similar read across chemicals has been reviewed to determine the toxic effect of the test chemical on micro-organisms.The studies are as mentioned below:

Short term toxicity to Pseudomonas putidastudy was carried out for 16 hr.The study was based on the effects of the test chemical on Pseudomonas putida at a temperature of 25ᵒC. Test chemical of known concentration was prepared in sterile double distilled water. Composition of test medium contains sodium nitrate (1.06 g), dipotassium hydrogen phosphate (0.6 g), magnesium sulphate (0.2 g), D (+) glucose (10 g), Difco bacto agar (18 g), ferrous sulphate (0.001 g), and 1.5 ml trace element solution. Pseudomonas putida was used as a test organism. Keep stock cultures of the test strain,Pseudomonas putida, on the nutrient for stock and preliminary culturesin agar slant tubes. Prepare, for onward culturingof the test strain, new stock cultures at intervals of1 week each. Incubate the inoculated stock cultures at 25"C for 24 h and keep in stock. stock. If needed, prepare preliminary cultures from stock cultures on the above mentioned nutrient medium in agar slant tubes and incubate at 25°C for 24 h. Then, wash off the cell material with sterile saline. Determine the extinction of the monochromatic radiation at 436nm for a 10 mm layer of the bacterial suspension by photoelectric measurement.Erlenmeyer flask of 300 ml stoppered with cottoned lined plastic caps was used for the study.Prepare dilution series in the test vessel.Each of the dilutions contains 1 part v/v of the pollutant solution in 20 to 214 parts v/v of mixture. Prepare the dilution series as follows: the first flask of each series contains 160ml of pollutant solution at the start. Starting from this flask prepare the subsequent dilution stein at a constant dilution ratio by consistently mixing 80ml of preliminary pollutant dilution and 8O 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 each of stock solution IIand 10 ml each ofthe preparedbacterial suspensionfrom the preliminary culture having a known adjusted extinction value. Leave both inoculated and non-inoculated dilutionseries at 25°C for 16 h. After termination of the test period measure the extinction of the monochromatic radiation at 436 nm in a 10-mm layer in the inoculated dilution series. On the basis of the effect of test chemical on growth rate, i.e, multiplication of the test organism Pseudomonas putida, the 16 h EC0 value was determined to be 115 mg/l.

For the test chemical, another toxicity study to micro-organisms was carried out according to the same procedure as mentioned above. In this study, on the basis of the effect of test chemical on growth rate, i.e, multiplication of the test organism Pseudomonas putida, the 16 h EC0 value was determined to be 83 mg/l.

On the basis of the experimental studies of the structurally and functionally similar read across chemical and applying the weight of evidence approach, the EC0 value the test chemical on the growth rate, i.e, multiplication of the test organism Pseudomonas putida can be expected to be ranges from 83 to 115 mg/l, respectively.

Description of key information

On the basis of the experimental studies of the structurally and functionally similar read across chemical and applying the weight of evidence approach, the EC0 value the test chemical on the growth rate, i.e, multiplication of the test organism Pseudomonas putida can be expected to be ranges from 83 to 115 mg/l, respectively.

Additional information

Data available for the structurally and functionally similar read across chemicals has been reviewed to determine the toxic effect of the test chemical on micro-organisms. The studies are as mentioned below:

 

Short term toxicity to Pseudomonas putida study was carried out for 16 hr. The study was based on the effects of the test chemical on Pseudomonas putida at a temperature of 25ᵒC. Test chemical of known concentration was prepared in sterile double distilled water. Composition of test medium contains sodium nitrate (1.06 g), dipotassium hydrogen phosphate (0.6 g), magnesium sulphate (0.2 g), D (+) glucose (10 g), Difco bacto agar (18 g), ferrous sulphate (0.001 g), and 1.5 ml trace element solution. Pseudomonas putida was used as a test organism. Keep stock cultures of the test strain, Pseudomonas putida, on the nutrient for stock and preliminary cultures in agar slant tubes. Prepare, for onward culturing of the test strain, new stock cultures at intervals of1 week each. Incubate the inoculated stock cultures at 25"C for 24 h and keep in stock. stock. If needed, prepare preliminary cultures from stock cultures on the above mentioned nutrient medium in agar slant tubes and incubate at 25°C for 24 h. Then, wash off the cell material with sterile saline. Determine the extinction of the monochromatic radiation at 436nm for a 10 mm layer of the bacterial suspension by photoelectric measurement. Erlenmeyer flask of 300 ml stoppered with cottoned lined plastic caps was used for the study. Prepare dilution series in the test vessel. Each of the dilutions contains 1 part v/v of the pollutant solution in 20 to 214 parts v/v of mixture. Prepare the dilution series as follows: the first flask of each series contains 160ml of pollutant solution at the start. Starting from this flask prepare the subsequent dilution stein at a constant dilution ratio by consistently mixing 80ml of preliminary pollutant dilution and 8O 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 each of stock solution II and 10 ml each of the prepared bacterial suspension from the preliminary culture having a known adjusted extinction value. Leave both inoculated and non-inoculated dilution series at 25°C for 16 h. After termination of the test period measure the extinction of the monochromatic radiation at 436 nm in a 10-mm layer in the inoculated dilution series. On the basis of the effect of test chemical on growth rate, i.e, multiplication of the test organism Pseudomonas putida, the 16 h EC0 value was determined to be 115 mg/l.

 

For the test chemical, another toxicity study to micro-organisms was carried out according to the same procedure as mentioned above. In this study, on the basis of the effect of test chemical on growth rate, i.e, multiplication of the test organism Pseudomonas putida, the 16 h EC0 value was determined to be 83 mg/l.

 

On the basis of the experimental studies of the structurally and functionally similar read across chemical and applying the weight of evidence approach, the EC0 value the test chemical on the growth rate, i.e, multiplication of the test organism Pseudomonas putida can be expected to be ranges from 83 to 115 mg/l, respectively.