Potassium hydrogen -5-amino-4-hydroxybenzene-1,3-disulphonate

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

similar to OECD 209

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Potassium hydrogen -5-amino-4-hydroxybenzene-1,3-disulphonate

EC Number:

280-719-6

EC Name:

Potassium hydrogen -5-amino-4-hydroxybenzene-1,3-disulphonate

Cas Number:

83763-34-2

Molecular formula:

C6H7NO7S2.K

IUPAC Name:

potassium hydrogen -5-amino-4-hydroxybenzene-1,3-disulphonate

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION OF TEST SOLUTION

Preparation of the saturated solution: The test item was weighed out and directly dispersed in water.

Test organisms

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Origin: Severn Trent PLC Sewage Treatment Plant, Belper, Derbyshire.
- non-adapted activated sludge, receives predominatly municipal sewage and hardly industrial chemical waste
- Preatreatment: the sludge was maintained at 21°C with continuous aeration and used on the day of collection. The pH was buffered to pH 7.2 with sodium hydroxide solution and the suspended solids level adjusted to 3.8 g/L prior to use.

Study design

Test type:

static

Limit test:

yes

Total exposure duration:

3 h

Remarks on exposure duration:

A range-finding test was carried out with the concentrations: 1 - 10 - 100 - 1000 mg/L. Based on the results of the preliminary test the study the main study was conducted with the test concentration of 100 mg/L.

Test conditions

Test temperature:

21°C

pH:

7.2

Nominal and measured concentrations:

Nominal concentration: 100 mg/L

Details on test conditions:

TEST SYSTEM

- test item concentration (directly weighing)



TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 1 mg/L, 10 mg/L, 100 mg/L, 1000 mg/L
- Results used to determine the conditions for the definitive study: based on the results of the preliminary test the study was carried out with a test concentration of 100 mg/L with 3 replicates. Two control replicates without test item and two replicates with the reference substance were included.

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Results with reference substance (positive control):

In the reference test the EC50-value for 3,5-dichlorophenol was EC50 (3 h) = 12 mg/L
The two control respiration rates differ not more than 15 % in the study.

Any other information on results incl. tables

Results of the range finding test:

Table 1: Inhibitions of the range-finding test

Concentration [mg/L]	Inhibition [%]
1	8
10	5
100	5
1000	100

Table 2: Respiration rates and inhibition of respiration of test and reference item concentrations

	Concentration [mg/L]	Respiration Rate [mg/O2/L/ min]	Inhibition [%]
Control - R1	-	0.36	-
Control - R2	-	0.31	-
Test item - R1	100	0.31	7
Test item - R2	100	0.30	10
Test item - R3	100	0.31	7
Reference item	3.2	0.28	16
Reference item	32	0.02	94

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

The EC50-value for the reference item was 12 mg/L.

Conclusions:

The test item is not toxic at concentration

Executive summary:

A Respiration Inhibition Test with activated sludge similar to OECD Guideline No. 209 was performed with the test item. Test system was activated sludge of a municipal treatment plant. The test was performed under static conditions with the nominal concentration of 100 mg/L. The respiration rates of control, reference and test item concentrations were measured after a contact time of three hours, and the inhibitory effects of the test and reference concentrations were determined in comparison to the control respiration rates. No inhibition of the test item was observed at the tested concentration.

In order to check the activity of the test system and the test conditions a reference test was carried out with 3,5 -dichlorophenol as reference item and the reference toxicity was determined. The EC50- value for the reference item was 12 mg/L.

Validity criteria of the test guideline were fulfilled.

The test item is not toxic at concentrations ≤ 100 mg/L to activated sludge of a municipal sewage treatment plant.