4'-chloro-2',5'-dimethoxyacetoacetanilide

Toxicity to microorganisms

Administrative data

Endpoint:

toxicity to microorganisms

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study report contained sufficient data for evaluation.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)

Version / remarks:

according to the draft of November 1978

Deviations:

yes

Remarks:

Difference to test standard: at the time of the test the use of a reference substance to control the sensitivity of the used Pseudomonas strain was not yet a standard procedure. To the final guideline: temperature

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

4'-chloro-2',5'-dimethoxyacetoacetanilide

EC Number:

224-638-6

EC Name:

4'-chloro-2',5'-dimethoxyacetoacetanilide

Cas Number:

4433-79-8

Molecular formula:

C12H14ClNO4

IUPAC Name:

N-(4-chloro-2,5-dimethoxyphenyl)-3-oxobutanamide

Details on test material:

- Name of test material (as cited in study report): Acetessig-2,5-dimethoxy-4-chloranilinide
- Analytical purity: > 99% (CoA, April 1988)

Sampling and analysis

Analytical monitoring:

not specified

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Preparation of stocksolution: not mnentioned in the alabaroty manuscript
- Addition of test substance: 0.5 g/ l in de-ionized water, following by stirring (24 h)
- pH-Adjustment: finally 7.3
- Filtration due to undissolved matter.
- DOC analysis stock solution: 105 mg C/l, according to 198 mg test substance / l (calculated from C-content 53.05% C in the formula)

- final dilution with bacterial suspension: 1+1, corresponds to approx. 100 - 110 mg/l test substance in the test solution
- (Use of) reference substance: no data

Test organisms

Test organisms (species):

Pseudomonas putida

Details on inoculum:

Origin strain: Pseudomonas putida MIGULA, DSM 50026, by Deutsche Sammlung Mikroorganismnen, Mascheroder Wer 1b, D-38124 Braunschweig.
- Laboratory pre culture: according to DIN standard cited
- Acclimitasation to test substance: no
- Initial biomass concentration: Diluted to a turbidity of 5 FAU (formazine attenuation units)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

16 h

Remarks on exposure duration:

+- 1 h

Post exposure observation period:

no

Test conditions

Test temperature:

21-22 ° C followed the DIN method cited. In the final ISO standard method a temperature of 25 - 30° C is required.

pH:

pH stock solution prior to dilution: 7.3

Dissolved oxygen:

Din standard medium

Salinity:

Din standard medium

Nominal and measured concentrations:

Measured concentration DOC stock solution: 105 mg C /l, corresponds to 198 mg test substance / l, after dilution with bacteria suspension approx. 100 - 110 mg/ l

Reference substance (positive control):

not specified

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

16 h

Dose descriptor:

EC10

Effect conc.:

> 110 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

other: DOC

Basis for effect:

growth inhibition

Remarks:

measured by absorption

Effect concentrations 2

Duration:

16 h

Dose descriptor:

EC50

Effect conc.:

> 110 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

other: DOC

Basis for effect:

growth inhibition

Remarks:

measured by absorption

Details on results:

Measures taken 16 h + - 1 h

Results with reference substance (positive control):

no data of use of reference substance in parallel to test substance

Any other information on results incl. tables

	Absorption at 436 nm		Dilution Factor (F)	Mean * F	Inhibition
Blank 1	0.247	0.221	10	2.434
Blank 2	0.247	0.231
Blank 3	0.271
test substance	0.252	0.260	10	2.560	0 %

where Inhibition = absorbance (blank) – absorbance (substance) / absorbance (blank) – absorbance (inoculum)

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

At the tested concentration of approx. 100 - 110 mg test substance / l bacterial suspension no significant inhibition could be observed.