Triiron tetraoxide

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Justification for type of information:

see attachment "Read-across justification-environ assessment-iron oxides" and “Endpoint-specific read-across justification for nano forms of iron oxide, 2021” attached in IUCLID section 13.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

The test item was insoluble in water. Treatment in an ultrasonic bath (1 h) resulted in red-brown colouration of the flask content, indicating fine dispersal of the test item. After treatment on a magnetic stirrer for 24 h, the suspension was tested without filtration.

Validity criteria fulfilled:

yes

Remarks:

The immobilisation and other abnormalities in the controls did not exceed 10% by the end of the test. The dissolved oxygen concentration remained above 3 mg/L throughout the exposure period.

Conclusions:

The observed 48-hour EC50 on Daphnia magna was >/= 100 mg/l. The test was conducted according to guideline OECD 202.

Executive summary:

The acute toxicity of diiron trioxide to Daphnia magna STRAUS was conducted in a static test. Observations were made on the swimming ability and the immobilisation rate, respectively, after 24 and 48 hours of exposure. The test item was insoluble in water. Treatment in an ultrasonic bath (1 h) resulted in red-brown colouration of the flask content, indicating fine dispersal of the test item. After treatment on a magnetic stirrer for 24 h, the suspension was tested without filtration. The results are expressed in terms of nominal concentrations. Defined concentrations of the test item led to a certain percentage proportion of immobilised Daphnia at the end of the 48 hour study period. Immobilisation rates were recorded at 24-hour intervals. The EC 0 and the EC 100 were determined directly from the study, while the EC 50 was calculated or read from the concentration/percentage response curve. Additionally any abnormal behaviour or appearance of the Daphnia was reported. The Test was carried out without chemical analysis. The test was only conducted at a nominal concentration of 100 mg/L.

No toxic effects against daphnia were observed at a limit test concentration of 100 mg/L under static conditions.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Justification for type of information:

see attachment "Read-across justification-environ assessment-iron oxides" and “Endpoint-specific read-across justification for nano forms of iron oxide, 2021” attached in IUCLID section 13.

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes

Analytical monitoring:

no

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Duration:

48 h

Dose descriptor:

other: EL0 (= Effective Loading)

Effect conc.:

>= 10 000 mg/L

Conc. based on:

test mat.

Basis for effect:

mobility

Validity criteria fulfilled:

not specified

Remarks:

Since the test is poorly reported the validity criteria cannot be assessed sufficiently. Nevertheless the test is considered as valid based on the data given.

Conclusions:

For triiron tetraoxide a 48-hour EL0 (effective loading) of >/= 10000 mg/L (nominal concentration) was observed on Daphnia magna.

Executive summary:

For triiron tetraoxide a 48-hour EL0 (effective loading) of >/= 10000 mg/L (nominal concentration) was observed on Daphnia magna. The method used was EU Method C.2 (Acute Toxicity for Daphnia).

Groups of 10 daphnids were exposed to a limit test concentration of nominally 10000 mg/L of triiron tetraoxid dissolved in water. To remove undissolved particles, the resulting emulsion was filtered using a folded filter of the pore size 7-12 µm. 2 replicates were performed.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions

Justification for type of information:

see attachment "Read-across justification-environ assessment-iron oxides" and “Endpoint-specific read-across justification for nano forms of iron oxide, 2021” attached in IUCLID section 13.

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

>= 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Validity criteria fulfilled:

not specified

Remarks:

Since the test is poorly reported the validity criteria cannot be assessed sufficiently. Nevertheless the test is considered as valid based on the data given.

Conclusions:

A 48 -hour EC0 of >/= 10000 mg/L was received for zinc ferrite on Daphnia magna.

Executive summary:

A 48 -hour EC0 of >/= 10000 mg/L was received for zinc ferrite on Daphnia magna. The method used was EU Method C.2 (Acute Toxicity for Daphnia).

Details in the procedure of the test method, which affected the result:To produce the only test concentration, the test substance was weighed into water,treated with an ultrasonic bath for 1 h and afterwards stirred on a magnetic stirrer for 24 h. To remove undissolved particles, the resulting suspension was filtered using a folded filter of the pore size 7 -12 µm. The concentrations presented are nominal. No analytical monitoring of the test substance was performed.

Reference 4

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

1999

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions

Justification for type of information:

see attachment "Read-across justification-environ assessment-iron oxides" and “Endpoint-specific read-across justification for nano forms of iron oxide, 2021” attached in IUCLID section 13.

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Limit test:

yes

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

>= 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Validity criteria fulfilled:

not specified

Remarks:

Since the test is poorly reported the validity criteria cannot be assessed sufficiently. Nevertheless the test is considered as valid based on the data given.

Conclusions:

Manganese ferrite had no effect (EC0) at a concentration of 10000 mg/L on the invertebrate Daphnia magna in a 24 h and 48 h test according to EU Method C.2.

Executive summary:

Manganese ferrite had no effect (EC0) at a concentration of 10000 mg/L on the invertebrate Daphnia magna in a 24 h and 48 h test according to EU Method C.2.

The following points are important for the test result: 10000 mg/l of the test substance was directly weighed into water, treated for 60 seconds at 8000 rpm with an ultra turrax and stirred for 24 hours on a magnetic stirrer. To remove undissolved particles, the resulting emulsion was filtered using a folded filter of the pore size 7-12 µm. No analytical monitoring was performed.

Reference 5

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP-Guideline study

Justification for type of information:

see attachment "Read-across justification-environ assessment-iron oxides" and “Endpoint-specific read-across justification for nano forms of iron oxide, 2021” attached in IUCLID section 13.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

The test item was insoluble in water. Treatment in an ultrasonic bath (1 h) resulted in red-brown colouration of the flask content, indicating fine dispersal of the test item. After treatment on a magnetic stirrer for 24 h, the suspension was tested without filtration.

Validity criteria fulfilled:

yes

Remarks:

The immobilisation and other abnormalities in the controls did not exceed 10% by the end of the test. The dissolved oxygen concentration remained above 3 mg/L throughout the exposure period.

Conclusions:

For iron hydroxide oxide the observed 48 hour EC50 on Daphnia magna was >/= 100 mg/L. The determination was performed according to OECD Guideline 202.

Executive summary:

The determination was performed according to OECD Guideline 202 (Currenta 2008).

The Daphnia were exposed to a limit test concentration of nominally 100 mg/L of iron hydroxide oxide dissolved in water. Auxiliaries used to prepare the test media were an ultrasonic bath and a magnetic stirrer.

Observations were made on the swimming ability and the immobilisation rate, respectively, after 24 and 48 hours of exposure. The test item was insoluble in dilution water. Treatment in an ultrasonic bath (1 h) resulted in yellow-brown colouration of the flask content, indicating fine dispersal of the test item. After treatment on a magnetic stirrer for 24 h, the suspension was tested without filtration.

No toxic effects against daphnia were observed at a limit test concentration of 100 mg/L under static conditions.

Description of key information

Applying read-across to micro- and nano-sized iron (hydr)oxides (see attachment "Read-across justification-environ assessment-iron oxides" in section 13), micro-sized iron (hydr)oxides are not considered acutely toxic to aquatic invertebrates. For micro- and nano -sized iron (hydr)oxides, the observed 48-h EC50 values for the immobilization of Daphnia magna range from > 100 mg/L to > 10,000 mg/L, a concentration that is 100-fold above the corresponding OECD test limit.

Additional information

For micro- and nano-sized iron (hydr)oxides, five reliable studies on short-term toxicity to aquatic invertebrates are available. No acute toxicity was observed in Daphnia magna exposed to micro- and nano-sized iron (hydr)oxide forms, and unbounded 48 h EC50 values of > 100 mg/L were derived.

 

In a reliable study with Daphnia magna according to OECD 202 (Neuhahn, 2008), an unbounded 48 h EC50 value of > 100 mg/L (nominal) was derived for acute toxicity of micro-sized diiron trioxide, as no toxic effects were observed at the limit test concentration of 100 mg/L under static conditions.

 

Unbounded 48 h EC50 values of > 10 g/L (nominal) were derived for micro-sized triiron tetraoxide (Caspers, 2000), zinc ferrite brown spinel (Caspers, 1999) and manganese ferrite black spinel (Caspers, 2000) in reliable studies with Daphnia magna according to EU Method C.2 (Acute toxicity to Daphnia).

 

Acute toxicity of iron (hydr)oxide nanoforms to aquatic invertebrates was investigated in a reliable study with nano-alpha iron hydroxide oxide yellow according to OECD 202 (Neuhahn, 2008). Toxic effects to Daphnia magna were not observed at a limit test concentration of 100 mg/L under static conditions and an unbounded 48 h EC 50 value of > 100 mg/L (nominal) was derived.

 

Based on read-across to micro- and nano-sized iron (hydr)oxides (see attachment "Endpoint-specific read-across justification for the iron oxide category" in section 13), available data indicate a low potential for acute toxicity of iron (hydr)oxides to aquatic invertebrates (see table below). Acute toxicity of micro- and nano-sized iron (hydr)oxides to aquatic invertebrates was not observed up to 10 g/L (Caspers, 1999; Caspers, 2000), a concentration that is 100-fold above the corresponding OECD test limit for acute toxicity.

 

Table: Acute toxicity of iron (hydr)oxides to aquatic invertebrates. 

Endpoint	Test species	Test results	Test material/form	Reliability: Reference
Short-term toxicity to aquatic invertebrates	Daphnia magna	EC50 (48h): > 100 mg/L nominal	diiron trioxide / powder	RL2: Neuhahn, 2008
.	Daphnia magna	EC0 (48 h): >= 10 g/L nominal	triiron tetraoxide /powder	RL2: Caspers, 2000
.	Daphnia magna	EC0 (48 h): >= 10 g/L nominal	zinc ferrite brown spinel / powder	RL2: Caspers, 1999
.	Daphnia magna	EC0 (48 h): >= 10 g/L nominal	manganese ferrite black spinel / powder	RL2: Caspers, 2000
.	Daphnia magna	EC50 (48h): > 100 mg/L nominal	iron hydroxide oxide yellow / nano, alpha	RL2:Neuhahn, 2008