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Ecotoxicological information

Toxicity to microorganisms

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Administrative data

Endpoint:
toxicity to microorganisms
Type of information:
experimental study
Adequacy of study:
key study
Study period:
22 June 1992 - 01 July 1992
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study meets generally accepted scientific principles

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report Date:
1992

Materials and methods

Principles of method if other than guideline:
Determination of the biological toxicity of substances hazardous in water to Pseudomonas putida according to Bringmann and Kühn (Bringmann, G. and Kühn, R.: Zeitschrift für Wasser- und Abwasser-Forschung 10 (1977) p. 87-98).

Principles:
The test organism (Pseudomonas putida) was incubated in a defined liquid growth medium with different concentrations of test substance over multiple generations at 24.8 - 25 °C during 18 ± 1 hours. The cell density was determined photometrically as the extinction of the cell suspension at 436 nm. The inhibition of cell growth in presence of test substance compared to that of the control was derived grahically from the extinction values measured at the end of the incubation period.
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid
Details on test material:
- Name of test material (as cited in study report): MARLOPON AT 50
- Physical state: yellow-brown liquid
- Analytical purity: 56.2% Benzenesulfonic acid, C10-13-alkyl derivs., compds. with triethanolamine (CAS no. 68411-31-4) (of which 92% alkylbenzolsulfonate-triethanolamine salt)
- CAS no.: 68411-31-4
- Lot/batch No.: 621
- Production date of the lot/batch:1/92
- Expiration date of the lot/batch:1/93

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Pseudomonas putida
Details on inoculum:
The extinction of bacterial inoculum was measured using a Zeiss-Photometer PM 6 at a wavelength of 436 nm, and diluted with NaCl-solution to a extinction value of 0.300 (± 5%) before inoculation of the test solutions.

Study design

Test type:
static
Water media type:
not specified
Limit test:
no
Total exposure duration:
18 h
Post exposure observation period:
None

Test conditions

Test temperature:
24.8 - 25.0 °C
pH:
pH of the different test substance control dilutions (no bacteria added) without the nutrient solutions: 6-6.8
pH of the different test substance control dilutions (no bacteria added) with the nutrient solutions after 18 hours of incubation: 6.8
Nominal and measured concentrations:
0, 50, 100, 200 and 400 mg MARLOPON AT 50/L
which is equal to: 0, 28, 56, 112 and 225 mg Benzenesulfonic acid, C10-13-alkyl derivs., compds. with triethanolamine (CAS no. 68411-31-4)/L
Details on test conditions:
TEST SYSTEM
- Test vessel: 250 mL Erlymeyer flasks
- Type (delete if not applicable): closed with cellulose plugs
- Fill volume: 100 mL
- Aeration: not reported
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 5
- Biomass loading rate: The extiction (at 436 nm) of the bacterial inoculum was corrected with NaCl solution to 0.300 (± 5%) before addition to the test solutions

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: the test substance was diluted in bidest.

OTHER TEST CONDITIONS
- Adjustment of pH: no

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Cell density by measurement of extinction at 436 nm after 18 hours of incubation

TEST CONCENTRATIONS
- Spacing factor for test concentrations: factor 2
- Range finding study
- Test concentrations: 0, 100, 200, 400 and 800 mg MARLOPON AT 50/ml
- Results used to determine the conditions for the definitive study: the lowest tested concentration gave a 20% reduction compared to the control, all higher test concentrations gave a 85% reduction compared to the control. As the ojective was to derive a EC10, it was decide to repeat the test in which one more lower concentration (50 mg MARLOPON AT 50/L) was tested in the main test. This main test was done in duplicate.
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
18 h
Dose descriptor:
EC10
Effect conc.:
97 mg/L
Nominal / measured:
nominal
Conc. based on:
other: product (MARLOPON AT 50)
Basis for effect:
growth inhibition
Key result
Duration:
18 h
Dose descriptor:
EC10
Effect conc.:
55 mg/L
Nominal / measured:
nominal
Conc. based on:
other: CAS no. 68411-31-4
Basis for effect:
growth inhibition
Details on results:
The results for the pilot and two main experiments are given in the section 'any other information on results incl. tables' below. The EC10 derived grahpically from the extinction values obtained in the main experiment A and B were 110 and 84 mg MARLOPON AT 50/L, giving an average EC10 of 92 mg MARLOPON AT 50/L. This can be recalculated to 92 * 0.562 = 55 mg Benzenesulfonic acid, C10-13-alkyl derivs., compds. with triethanolamine (CAS no. 68411-31-4)/L.

Any other information on results incl. tables

Table 1. Pilot experiment: Effect of MARLOPON AT 50 on the growth of Pseudomonas putida after 18 hours of incubation, measured photometrical as extinction at 436 nm.

Concentration MARLOPON AT 50 (mg/L)

Extinction (436 nm)

Replica 1

Replica 2

Replica 3

Replica 4

Replica 5

Mean

0

480

470

487

467

492

479

100

380

382

388

 

 

383

200

60

63

61

 

 

61

400

69

66

63

 

 

66

800

65

67

67

 

 

66

 

Table 2. Main experiment A: Effect of MARLOPON AT 50 on the growth of Pseudomonas putida after 18 hours of incubation, measured photometrical as extinction at 436 nm.

Concentration MARLOPON AT 50 (mg/L)

Extinction (436 nm)

Replica 1

Replica 2

Replica 3

Replica 4

Replica 5

Mean

0

478

405

404

407

387

416

50

486

485

465

 

 

479

100

400

394

399

 

 

398

200

61

61

62

 

 

61

400

66

70

68

 

 

68

 

Table 3. Main experiment B: Effect of MARLOPON AT 50 on the growth of Pseudomonas putida after 18 hours of incubation, measured photometrical as extinction at 436 nm.

Concentration MARLOPON AT 50 (mg/L)

Extinction (436 nm)

Replica 1

Replica 2

Replica 3

Replica 4

Replica 5

Mean

0

512

571

476

517

492

514

50

508

502

536

 

 

515

100

421

436

439

 

 

432

200

68

70

68

 

 

69

400

74

77

76

 

 

76

Applicant's summary and conclusion

Validity criteria fulfilled:
not applicable
Conclusions:
The 18 h EC10 for Pseudomonas putida was 55 mg/L, based on growth inhibition.
Executive summary:

The test organism (Pseudomonas putida) was incubated in a defined liquid growth medium with different concentrations of test substance over multiple generations at 24.8 - 25 °C during 18 ± 1 hours. The following concentrations were tested: 0, 50, 100, 200 and 400 mg MARLOPON AT 50/L which is equal to: 0, 28, 56, 112 and 225 mg Benzenesulfonic acid, C10-13-alkyl derivs., compds. with triethanolamine (CAS no. 68411-31-4)/L.

After 18 hours, the cell density was determined photometrically as the extinction of the cell suspension at 436 nm. The inhibition of cell growth in presence of test substance compared to that of the control was derived grahically from the extinction values measured at the end of the incubation period.

The 18 h EC10 for Pseudomonas putida was 92 mg MARLOPON AT 50/ ml which is equal to 55 mg Benzenesulfonic acid, C10-13-alkyl derivs., compds. with triethanolamine (CAS no. 68411-31-4)/L based on growth inhibition.