1-amino-4-hydroxy-2-phenoxyanthraquinone

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:

from July 25th to July 28th, 1997

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Basic data are provided in the report.

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Deviations:

no

GLP compliance:

no

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

activated sludge

Details on inoculum:

- pH of the sludge: 6.8
- Sludge dry mass: 1.62 g/l

Test type:

static

Water media type:

not specified

Limit test:

no

Total exposure duration:

3 h

pH:

7.7 - 7.9

Nominal and measured concentrations:

Nominal: 1000 mg/l, 400 mg/l, 160 mg/l and 64 mg/l

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol

Duration:

3 h

Dose descriptor:

IC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Duration:

3 h

Dose descriptor:

other: IC 20

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: IC 50 (3 h) of positive control = 9.1 mg/l

Table 1: Results with control

Control	pH after 3 h	O2-consumption (in cm)^(1)	Time (cm)^(2)	mg O2 pro min./l	Ø control	Deviation of the control in %
1 2	8.0 7.8	4.9 4.8	4.3 4.7	0.91 0.82	0.86	11.58 10.38

Table 2: Results of Activated Sludge Respiratory Inhibition at tested concentrations

Test substance (mg/l)	pH after 3 h	O2-consumption (in cm)^(1)	Time (cm)^(2)	mg O2 pro min./l	% of control	% of inhibition
1000 400 160 64	7.7 7.8 7.9 7.8	5.7 5.0 4.8 5.2	5.0 4.5 4.6 4.6	0.91 0.89 0.83 0.90	105.52 102.84 96.58 104.63	0.00 0.00 3.42 0.00

Table 3: Results with positive control

Positive control: 3,5 - dichlorophenol (mg/l)	pH after 3 h	O2-consumption (in cm)^(1)	Time (cm)^(2)	mg O2 pro min./l	% of control	% of inhibition
32 10 3.2	8.1 8.0 8.0	1.0 2.3 4.5	4.9 4.7 5.2	0.16 0.39 0.69	18.89 45.29 80.10	81.11 54.71 19.76

Keys:

⁽¹⁾ 2 cm = 0.8 mg/l O2

⁽²⁾ 2 cm = 1 min.

Conclusions:

IC50(3h) > 1000 mg/l

Executive summary:

The inhibitory effect of the substance on oxygen consumption of activated sludge microorganisms was tested according to the OECD Guideline 209: Activated Sludge, Respiration Inhibition Test, adopted on April 4th, 1984.

Nominal concentrations of the test substance used in the study were 1000 mg/l, 400 mg/l, 160 mg/l and 64 mg/l.

The positive control used was 3,5-dichlorophenol which gave an IC 50 (3 h) = 9.1 mg/l.

Under the conditions of the test, the IC 50 (3 h) and IC 20 (3 h) were both estimated to be > 1000 mg/l.

Description of key information

IC 50 (3 h) > 1000 mg/l.

Key value for chemical safety assessment

EC50 for microorganisms:

1 000 mg/L

Additional information

The substance was tested for toxicity to microorganisms in five experiments, according to:

- OECD guideline 209 "Activated Sludge, Respiration Inhibition Test" (1997)

- ISO 8192 B, Test for inhibition of oxygen consumption by activated sludge (1990)

- a scientifically acceptable method: internal method B-10, BST-KST (1980, 1978, 1977).

The results obtained, listed in order of the above mentioned tests, were the following:

- IC50 (3 h) > 1000 mg/l (1997), where 1000 mg/l is the highest concentration tested and this is the most comprehensive study

- EC50 (30 min) > 100 mg/l (1990), where 100 mg/l is the only concentration tested

- BST > 300 mg/l (1980, 1978, 1977).