REAKTIV-GELB F-68 072 FW

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:

05 April 2006 to 28 April 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

no

Principles of method if other than guideline:

The method is based on that described by ETAD (Ecological and Toxicological Association of the Dyestuffs Manufacturing Industry), in which activated sludge obtained from a sewage treatment plant is used as the microbial source.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Details on sampling:

The test item and reference substance concentrations are not confirmed by analytical methods; they are based on nominal concentrations.

Vehicle:

no

Details on test solutions:

Concentration reference substance (3.5-Dichlorophenol, mg/L): 5, 10, 20

Test organisms (species):

activated sludge

Details on inoculum:

Type: mixed population of aquatic microorganisms (activated sludge)
Origin: aeration tank of a domestic sewage treatment plant (Municipal STP Cologne-Stammheim)
Date of collection: 2006-04-18
Pretreatment: aeration of the activated sludge, daily fed with synthetic medium
pH of the suspension before application: 7.8
Synthetic sewage feed: A synthetic sewage feed is made by dissolving the following amounts of substance in 1 litre of water.
16.0 g peptone
11.0 g meat extract
3.0 g urea
0.7 g NaCl
0.4 g CaCl2 2H2O
0.2 g MgSO4 7H20
2.8 g K2HOP4
pH of the synthetic sewage feed: 7.1

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

3 h

Post exposure observation period:

No post exposure observation period

Hardness:

No data

Test temperature:

21.3-21.7 °C

pH:

7.8-8.1

Dissolved oxygen:

2.5-4.5 mg/L

Salinity:

Not applicable.

Nominal and measured concentrations:

Test concentrations (mg/L): 100, 1000, 10000 mg/L
Test item concentration in physico-chemical oxygen consumption control (mg/L) : 10000

Details on test conditions:

Type of application: direct weighing
Test concentration of the activated sludge: 1200 mg/L suspended solids
Test temperature: 20 + 2° C
Stirring period of test item before start of incubation time: 16 hours
Incubation time: 3 hours with permanent aeration

The physico-chemical oxygen consumption control is carried out, since some substances may consume oxygen by chemical reactivity, in order to be able to differentiate between physico-chemical oxygen consumption and biological oxygen consumption (respiration), at least the maximum concentration of the test item is additionally tested without activated sludge.

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Details on results:

The physico-chemical oxygen consumption has been determined at 10000 mg/l test substance concentration. As no physico-chemical oxygen consumption was observed at that test item concentration this observation also holds true for the lower test item concentrations.

Results with reference substance (positive control):

Reference substance : 3.5-Dichlorophenol

Test concentration [mg/1] Respiratory rate [mg/1 . h] Inhibition [%]
5 24.0 23.8
10 18.0 42.9
20 8.4 73.3


Reference compound

Reference compound name: 3.5 Dichlorophenol (Aldrich)
Purity: 97 %
Batch number: 15809KI-392

Comments: The reference substance concentrations result from the quantities used in the preparations and have not been confirmed by analytical methods

Reported statistics and error estimates:

None reported.

Test item       :     Reaktiv Gelb F68072 FW

 

Test concentration [mg/1]	Respiratory rate test item [mg/1 • h]	Phys.-chem. O2consumption [mg/1 • h]	Respiratory rate - phys.-chem. O2consumption [mg/1 • h]	Inhibition [%]
100	30.0	*0.0	30.0	4.8
1000	34.0	*0.0	34.0	0.0
10000	26.0	0.0	26.0	17.5
Control, mean	31.5
Control 1	30.0
Control 2	33.0

 

 

Comments relevant to result:

 

Test concentrations are given as nominal concentrations and have not been confirmed by analytical methods.

 

 

* The physico-chemical oxygen consumption has been determined at 10000 mg/l test substance concentration. As no physico-chemical oxygen consumption was observed at that test item concentration this observation also holds true for the lower test item concentrations

Validity criteria fulfilled:

yes

Conclusions:

Reaktiv Gelb F68072 FW showed 17.5 % respiration inhibition of activated sludge at a test item concentration of 10000 mg/L.

EC50 > 10000 mg/L

Executive summary:

A study was performed to assess the toxicity of Reaktiv Gelb F68072 FW to bacteria.

 

The study was in accordance with the Commission Directive 88/302/EEC Part C. 11.This test method is in most parts identical with OECD Guideline 209. Study conducted in compliance with the Principles of Good Laboratory Practice (GLP).

 

The activated sludge was exposed to Reaktiv Gelb F68072 FW at different concentrations. The respiration rate of each mixture was determined after aeration periods of 3 hours.

 

Reaktiv Gelb F68072 FW showed 17.5 % respiration inhibition of activated sludge at a test item concentration of 10000 mg/L.

 

The EC50 is higher than 10000 mg/L.

Description of key information

The EC50 is higher than 10000 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:

10 000 mg/L

Additional information

A study was performed to assess the toxicity of Reaktiv Gelb F68072 FW to bacteria.

 

The study was in accordance with the Commission Directive 88/302/EEC Part C. 11.This test method is in most parts identical with OECD Guideline 209. Study conducted in compliance with the Principles of Good Laboratory Practice (GLP).

 

The activated sludge was exposed to Reaktiv Gelb F68072 FW at different concentrations. The respiration rate of each mixture was determined after aeration periods of 3 hours.

 

Reaktiv Gelb F68072 FW showed 17.5 % respiration inhibition of activated sludge at a test item concentration of 10000 mg/L.