2,2'-(naphthalene-1,4-diyl)bis(benzoxazole)

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:

November 10, 1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Details on test solutions:

Test item was directly added to the testing solution. The test material was weighed directly into the vessels.

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Source: Municipal sewage treatment plant Frankfurt / M-Sindlingen.
- Amount used, activated sludge: 1600 mg/l dry weight.
- Pretreatment: according to the iindications described in the guidelines.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

20 ± 2 °C

pH:

7.2 ± 0.2

Nominal and measured concentrations:

Nominal, in the rage of 500 - 1000 mg/l

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Details on results:

EC20 (3h) > 1000 mg/l
EC80 (3h) > 1000 mg/l

Conclusions:

EC50 (3h) > 1000 mg/l (nominal)

Executive summary:

The respiration inhibition potential on activated sludge, the assay was conducted in accordance with OECD guideline 209 and EU Method C.

Test item was directly added to the testing solution. The test material was weighed directly into the vessels. The tested concentrations renged from 500 to 1000 mg/l. 3,5-Dichlorophenol was used as positive control. The EC20, EC50 and EC80 values, after 3 hours of exposure, resulted to be higher than 1000 mg/l.

Conclusion

EC50 (3h) > 1000 mg/l (nominal)

Description of key information

EC50 (3h) > 1000 mg/l (nominal)

Additional information

The respiration inhibition potential of Fluorescent Brightener 367 on activated sludge, the assay was conducted in accordance with OECD guideline 209 and EU Method C. Test item was directly added to the testing solution. The test material was weighed directly into the vessels. The tested concentrations renged from 500 to 1000 mg/l and the EC20, EC50 and EC80 values, after 3 hours of exposure, resulted to be higher than 1000 mg/l.