Ethyl undec-10-enoate

Toxicity to microorganisms

Administrative data

Endpoint:

toxicity to microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Report date:

1988

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: Bewertung wassergefährdender Stoffe (III), Bestimmung der akuten Bakterientoxizität, Ad-hoc-Arbeitsgruppe 1, LTwS, Nr. 10, Sept 1979

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Isopropyl myristate

EC Number:

203-751-4

EC Name:

Isopropyl myristate

Cas Number:

110-27-0

Molecular formula:

C17H34O2

IUPAC Name:

isopropyl myristate

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 10 mg TS was dissolved in ethanol absolute and after complete evaporation of the organic solvent, a solution of 10 mg/L in sterile Mill-Q water was prepared; 20 mg/L solution prepared similarly; both diluted (1.25 times) in Milli-Q water and mixed for 15 min with magnetic stirrer; pH was adjusted with NaOH

Test organisms

Test organisms (species):

Pseudomonas putida

Details on inoculum:

- Laboratory culture: Stock culture obtained from RIVM, Bilthoven, The Netherlands
- Method of cultivation: New stock cultures started in 1-week intervals; incubated at 25°C
- Preparation of inoculum for exposure: Extinction of the cultures were measured and adjusted to the final test with sterile saline corresponded with the extinction of a Formazin standard suspension at the value 10

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

18 h

Remarks on exposure duration:

± 2 h

Post exposure observation period:

not relevant

Test conditions

Test temperature:

25 °C

pH:

adjusted to 7.0

Nominal and measured concentrations:

nominal: 0, 0.004, 0.008, 0.016, 0.031, 0.063, 0.125, 0.25, 0.5, 1.0, 2.0, 4.0, 8.0, 16.0 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 300 mL Erlenmeyer flasks
- Type (delete if not applicable): closed with aluminium caps
- Material, size, headspace, fill volume: 100 mL test solution
- No. of organisms per vessel: adjusted to an extinction of 10 at 436 nm
- No. of vessels per concentration (replicates): 3 inoculated, 1 without inoculum

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Milli-Q water

OTHER TEST CONDITIONS
- Adjustment of pH: 7.0 with NaOH

EFFECT PARAMETERS MEASURED: Growth inhibition, measured as extinction at 436 nm

Reference substance (positive control):

yes

Remarks:

methanol

Results and discussion

Effect concentrations

Duration:

18 h

Dose descriptor:

EC50

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: the toxicity threshold of methanol was determined as 7537 mg/L, while the literature TT value of methanol was cited as 6600 mg/L

Reported statistics and error estimates:

Since all the measured extinction values were very close to the reference, no real toxicity threshold could be determined.

Any other information on results incl. tables

The solubility limit of the test substance was cited as 10 mg/L in the study (calculated from three solubility limits of a C8, a C14 and a C18 substance - correspondingly 680 mg/L, 20 mg/L and 3 mg/L, values indicated by sponsor); Extinction at 436 nm of different TS concentrations:

Concentration in mg/L	Mean extinction at 436 nm
0.004	0.416
0.008	0.418
0.016	0.407
0.031	0.411
0.063	0.400
0.125	0.397
0.250	0.395
0.500	0.403
1.0	0.413
2.0	0.403
4.0	0.414
8.0	0.431
16.0	0.449