Iron ores, agglomerates

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1989 (rewritten 2004)

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Although the test is considered reliable with restrictions the test results should not be used for the derivation of a PNEC STP for iron since an insoluble iron form (diiron trioxide have been used). But it can be used to demonstrate the absence of toxic effects towards micro organisms for similar iron compounds.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Diiron trioxide

EC Number:

215-168-2

EC Name:

Diiron trioxide

Cas Number:

1309-37-1

Molecular formula:

Fe2O3

IUPAC Name:

diiron trioxide

Constituent 2

Reference substance name:

Iron (III)oxide

IUPAC Name:

Iron (III)oxide

Details on test material:

Bayferrox 960 red; purity not specified
product No. 9028039, composition >= 88% Fe2O3, >= 3% SiO2 + Al2O3
loss on heating at 1000 °C (0.5 h) <= 11

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

activated sludge of a predominantly domestic sewage

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Results and discussion

Effect concentrations

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

Any other information on results incl. tables

nutrient solution: according to ISO 8192 (1986)

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

EC50 >= 10000mg/L

Executive summary:

Following the guideline ISO 8192 (Test for Inhibition of Oxygen Consumption by Activated Sludge) a 3-hour EC50 of > 10000 mg/l for Iron(III)oxide was obtained on activated sludge of a predominantly domestic sewage (Bayer AG 1989).