5-amino-2-chloro-N-(2,4-dimethylphenyl)benzenesulphonamide

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:

1991: May 14 to October 8

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Version / remarks:

(1984)

GLP compliance:

no

Analytical monitoring:

not specified

Test organisms (species):

activated sludge, domestic

Details on inoculum:

The tests were run with aerobic activated sludge from a domestlc waste-water treatment plant (ARA, Sissach/Switzerland).

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Post exposure observation period:

10 minutes

Hardness:

not specified

Test temperature:

21.5°C

pH:

initial pH: 8.2

Dissolved oxygen:

not specified

Salinity:

not specified

Conductivity:

not specified

Nominal and measured concentrations:

The following flasks were filled up to 500 mL final volume according to:

Flask 1 (control): 0 mg/L
Flask 12 (control): 0 mg/L
Flask 5 (ACDMA): 100 mg/L
Flask 6 (ACDMA): 10 mg/L
Flask 2 (3,5-dichlorophenol sodium salt): 50 mg/L
Flask 3 (3,5-dichlorophenol sodium salt): 10 mg/L
Flask 4 (3,5-dichlorophenol sodium salt): 3.2 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass-flask (>500 mL)
- Aeration: glass-flasks aerated with 0.5 L/minute of an air-flow of about 0.2 L/minute instead of 0.5L/minute to prevent possible foam development.
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 2
- No. of vessels per vehicle control (replicates): 0
- No. of vessels per abiotic control (replicates): 0
OTHER TEST CONDITIONS
- Adjustment of pH: not specified (initial pH of 8.2)
EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : oxygen consumption rate (per minute)
TEST CONCENTRATIONS
- Test concentrations: 10 and 100 mg/L

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Duration:

3 h

Dose descriptor:

IC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Results with reference substance (positive control):

IC50 of 3,5-dichlorophenol has been measured as 9.0 mg/L

Influence of ACDMA on oxygen consumption of activated sludge

Flask N°	Chemical	Concentration of test chemical (mg/L)	Oxygen consumption (mg O2/L min.)		Inhibition (%)	Starting pH
1	Control	-	0.69	Mean: 0.73 Deviation: 11.6%	-	8.2
12	Control	-	0.77		-	8.2
5	ACDMA	100	0.59		19.2	8.2
6	ACDMA	10	0.60		17.8	8.2

 

Influence of 3,5-dichlorophenol sodium salt on oxygen consumption of activated sludge

Flask N°	Chemical	Concentration of test chemical (mg/L)	Oxygen consumption (mg O2/L min.)		Inhibition (%)	Starting pH
1	Control	-	0.69	Mean: 0.73 Deviation: 11.6%	-	8.2
12	Control	-	0.77		-	8.2
2	3,5-dichlorophenol	50	0.06		91.8*	8.2
3	3,5-dichlorophenol	10	0.32		56.2*	8.2
4	3,5-dichlorophenol	3.2	0.57		21.9*	8.2

*: values used for the calculation of linear regression.Y = 58.048 x log(dose)-5.364 (R=0.996) -> IC50 : 9.0 mg/L

Validity criteria fulfilled:

yes

Remarks:

IC50 of positive control is in the range of 5-30 mg/L. The variation between the two control samples (start, end) is not >15%.

Conclusions:

Influence of ACDMA on oxygen consumption of activated sludge has been determined in test performed according to OECD TG 209 to derive an IC50 >100 mg/L.

Executive summary:

Influence of ACDMA on oxygen consumption of activated sludge has been determined in test performed according to OECD TG 209 to derive an IC50 >100 mg/L.

Description of key information

Influence of ACDMA on oxygen consumption of activated sludge has been determined in test performed according to OECD TG 209 to derive an IC50 >100 mg/L.