Cyclohexane-1,2,4-triyltris(ethylene)

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Remarks:

The study used an in-house method, but is an GLP study and is sufficiently documented.

Qualifier:

no guideline followed

Qualifier:

according to guideline

Guideline:

other: O2 consumption method with Pseudomonas putida

Deviations:

no

Principles of method if other than guideline:

Method: O2 consumption test with Pseudomonas putida, developed by Hüls AG. The principle of the method is to determine the consumption of oxygen of Pseudomonas putida by measurement of the oxygen content in closed test vessels with test medium, bacteria and different concentration of the test substance during incubation time (5.5 hours). The dose-response of the test substance on oxygen consumption is determined by comparison of the oxygen consumption rate between the control and the test vessel with the substance. The principle is comparable to the method according to guideline OECD209, with the difference that a pure culture of Pseudomonas putida is tested instead of a mixture of organisms in activated sludge.

GLP compliance:

yes

Analytical monitoring:

not required

Details on sampling:

- Concentrations: 0.1 mL/L; 0.5 mL/L; 1 mL/L; and 2 mL/L were tested
- Sampling method: at the end of incubation time HgCl2 (end concentration 3 mg/L) was added to the test vessels to stopp the reaction. Subsequently the oxygen concentration was measured.

Vehicle:

yes

Remarks:

Emulsifier

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test substance was directly added to the test vessels with test medium in different concentrations. The test substance was dispersed in the test medium by addition of 1mL of the emulsifier nonylphenolethoxypropoxylate (stock solution 10 mL emulsifier in 190 mL water) into the test medium in the test vessels. After that the innoculate culture medium was added.
- Controls: test medium without test substance and test medium without test substance with HgCl2
- Chemical name of vehicle: nonylphenolethoxypropoxylate
- Concentration of vehicle in test medium: 1mL emulsifier per test vessel (stock solution 10 mL emulsifier in 190 mL water)
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): not specified. An interaction of the emulsifier and the test substance cannot be completely excluded.

Test organisms (species):

Pseudomonas putida

Details on inoculum:

- Laboratory culture: Test organism Pseudomonas putida
- Source of the strain: Intitute for water, soil, and air hygiene (Berlin), afterwards stock culture in the laboratory
- Method of cultivation: Cultivation in test medium (stock solution I (contains buffer, glucose and trace elements) and II (contains iron sulfate and magnesium sulfate)
- Preparation of inoculum for exposure: liquid preculture, 19 h incubation, cell count 10 x 10^5 cells/mL
- Initial biomass concentration: 80 mL inoculum with 10 x 10^5 cells/mL

Test type:

static

Water media type:

other: test medium

Limit test:

no

Total exposure duration:

5.5 h

Remarks on exposure duration:

At the end of exposure, oxygen consumption was stopped by addition of 1mL HgCl2-solution to each test vessel.

Test temperature:

25 +/- 2 °C
Preculture 24.9-25.1 °C, Incubation 24.0-26.8 °C

Nominal and measured concentrations:

0.1 mL/L; 0.5 mL/L; 1 mL/L and 2 mL/L (nominal) were tested

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL BSB-flask with magnetic stirrer
- Type: closed
- Material, size, headspace, fill volume: glass, 100 mL, closed with ground glass joint
- Aeration: no
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 5 (1 replicate is used to determine test end)
- No. of vessels per abiotic control (replicates): 4
- Nutrients provided for bacteria: glucose (in stock solution I)
- Incubation for 5.5 h at 25 °C +/-2 °C agitated in an incubator

Key result

Duration:

5.5 h

Dose descriptor:

EC10

Effect conc.:

0.89 other: mL/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: Corresponding to an EC10 of 754 mg/L.

Details on results:

The EC10 value was determined two times based on 4 replicates. The first test results in an EC10 of 0.97 mL/L, the second test resulted in an EC10 of 0.80 mL/L. The mean value of both tests is an EC10 of 0.89 mL/L.The EC10 is the concentration were 10% inhibition of the oxygen consumption in comparison to the control was observed.

Reported statistics and error estimates:

The EC10 was calculated based on linear regression and probit analysis with the program Multiplan

Validity criteria fulfilled:

not specified

Conclusions:

The effect of the test substance on Pseudomonas putida has been examined in an oxygen consumption test. An EC10 has been determined to 0.89 mL/L for 1,2,4-Trivinylcyclohexane in the oxygen consumption test.

Description of key information

An EC10 of 0.89 mL/L has been determined in an oxygen consumption test with Pseudomonas putida, corresponding to an EC10 of 754 mg/L of 1,2,4-Trivinylcyclohexane.

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

754 mg/L

Additional information

The inhibition of the oxygen respiration rate of Pseudomonas putida by 1,2,4 -Trivinylcyclohexane has been examined in an oxygen consumption test by an in house developed method. In the dose-response test, the effect of the test substance on the oxygen consumption of Pseudomonas putida after 5.5 h has been tested. An EC10 of 0.89 mL/L has been determined, corresponding to an EC10 of 754 mg/L of 1,2,4-Trivinylcyclohexane in the oxygen consumption test.