Coumarin

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Data source

Reference

Reference Type:

other company data

Title:

Unnamed

Year:

1993

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Coumarin

EC Number:

202-086-7

EC Name:

Coumarin

Cas Number:

91-64-5

Molecular formula:

C9H6O2

IUPAC Name:

2H-chromen-2-one

Test material form:

other: solution

Details on test material:

-Material Source: Factory of Saint Fons Chemistry
-Substance type: pure substance
-Lot number 93 027 01

Sampling and analysis

Analytical monitoring:

not specified

Test solutions

Details on test solutions:

concentration tested (mg/l):463; 215; 100; 46.3; 21.5 and 10

Test organisms

Test organisms (species):

activated sludge

Study design

Test type:

static

Total exposure duration:

3 h

Test conditions

Test temperature:

20 degree

pH:

8.0

Nominal and measured concentrations:

concentration tested (mg/l):463; 215; 100; 46.3; 21.5 and 10(nominal)

Details on test conditions:

Temperature: 20 ℃
Aeration: Sintered n 1.
Flow: 50 l / h controlled
Test pictures containers test tubes 70 mm, round bottom
Total volume test: 500ml
For conditioning of sludge: the sludge is introduced into the test tube and placed under aeration 15 minutes before the introduction of the
product to the study. Their concentration in test is 1.5 g / l of dry matter
Cadence startup tests: Every 15 minutes
Time of sludge / product contact: 30 minutes and 3 hours.
The oxygen consumption speed is measured on mixtures transferred cells measure tight.
Concentrations tested: a range of concentrations geometric progression ∛5 is obtained by means of mother solution at 1 g / l in water redistilled
463, 215, 100, 46.3, 21.5 and 10 mg / l

Results and discussion

Effect concentrations

Duration:

3 h

Dose descriptor:

IC50

Effect conc.:

640 mg/L

Nominal / measured:

nominal

Conc. based on:

dissolved

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Details on results:

See "Any other information on results incl. tables

Any other information on results incl. tables

3- RESULTATS
Concentration en coumarine     en mg/L	blanc 463	463	215	100	46, 3	21, 5	10	témoin 0
incubation 30 mn
Activité respì-ratoire mg O2 . l/mn	0	0,412	0,515	0,604	0,651	0,666	0,692	0,637
inhibition% -30 m n		35	19	5	-2	-5	-9	/
incubation 3 h
Activité respì-ratoire mg O2 . l/mn	0	0,372	0,478	0,552	0,648	0,644	0,644	0,648
inhibition% -3 h		43	26	15	0	1	1	/

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In the test of ISO 8192-1986 (Méthod B) standard, COUMARIN inhibitory concentration of 50% of the oxygen consumption of activated sludge
conditions of urban origin is greater than 463 mg / l for a time incubation of 30 minutes.
For 3 hours of incubation, the EC50 is above 463 mg / l, which is approximately equal to 640 mg / l.

Executive summary:

Introduction: At the request of Christopher Gallet, SC /ORG, FINE/CF &PP(courierCG/DC-92106of12/07/1992) assessingbacterialtoxicityof coumarinwas studied inactivated sludgeusing astandard methodISO 8192, ed.of15/07/1986, entitled "Water Quality-inhibition testoxygen consumptionby activatedsludge"methodB.

Results:

The values corresponds to measured respiratory activity​ recorded in the laboratory. After 3 hours of incubation sludge still have a significant activity.

 The inhibition of respiration of the sludge product was estimated by exceeded 35% after 30 minutes of incubation.

 After 3 hours of incubation, the IC50 (inhibitory concentration 50% of the oxygen consumption) was extrapolated by projecting the results on log-probit graph trace of the regression line (see Annex No. l)

Conclusion: In the test of ISO 8192-1986 (Méthod B) standard, COUMARIN inhibitory concentration of 50% of the oxygen consumption of activated sludge conditions of urban origin is greater than 463 mg / l for a time incubation of 30 minutes.

For 3 hours of incubation, the EC50 is above 463 mg / l, which is approximately equal to 640 mg / l.