Diiron titanium pentaoxide

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is highly insoluble in water, hence indicating that aquatic toxicity is unlikely to occur

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

For Read-Across Justification please refer to Section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

not specified

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

Adopted: 13. April, 2004

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

- Name: Titanium dioxide (bulk)
- Supplier: Sigma-Aldrich Co.
- Lot No.: SZB90960
- Purity: 99.1%
- Appearance: White powder
- Storage conditions: Room temperature

Analytical monitoring:

yes

Details on sampling:

- Sampling method: 300 mL of the test solution sampled at the start of the test and after 48 hours later
- Sample storage conditions before analysis: not specified

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: because of the low water-solubility of the substance Water-Accommodated Fractions (WAF) were according to OECD guideline 23 (OECD, 2000); 0.101 g test substance filled into 1,000 mL volumetric flask and M4 medium filled up to 1,000 mL marker
- Stirring: yes, stirred for 48 hours
- Settling: settled in separatory funnel for 24 hours, precipitate removed
- Differential loading: a limit test was performed (limit loading rate:100 mg/L in nominal)
- Controls: negative control (M4 medium only), positive control using Potassium dichromate as reference substance at concentrations of 0.20, 0.40, 0.80, 1.60 and 3.20 mg/L (geometric series 2.0, nominal concentration)
- Evidence of undissolved material: no, WAF was performed and precipitate removed after a settling period of 24 hours

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Age at study initiation: not specified
- Source: Health Care Research Laboratory, KTR
- Age of parental stock: not specified
- Feeding during test : no
- Breeding concditions:
Photo period:16 hours light, 8 hours darkness
Feed: fed daily in the morning with Chlorella vulgaris

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

205.8 mg/L as CaCO3

Test temperature:

20.7 °C (Min. 20.4 - Max. 20.8) °C

pH:

7.89 (Min. 7.67 - Max. 8.05)

Dissolved oxygen:

7.92 mg/L (Min. 7.52 - Max. 8.22 ) mg/L

Salinity:

not applicable

Conductivity:

not specified

Nominal and measured concentrations:

Nominal loading rate (mg/L) : 0 (negative control), 100
Measured conentration:
at the start of the test: 0.04 mg/L (non-filtered test solution), <0.02 mg/L (filtered test solution, <0.45 μm PTFE membrane filter)
after 48 hours: 0.03 mg/L (non-filtered test solution), <0.02 mg/L (filtered test solution, <0.45 μm PTFE membrane filter)

Details on test conditions:

TEST SYSTEM
- Test vessel: not specified
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration: 4
- No. of vessels per control: 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: M4 medium

OTHER TEST CONDITIONS
- Adjustment of pH: not specified
- Photoperiod: 16 hours of light and 8 hours of dark
- Light intensity: not reported

EFFECT PARAMETERS MEASURED: immobilisation , abnormal behavior

RANGE-FINDING STUDY
- Test concentrations: 100, 500 and 1000 mg/L
- Results used to determine the conditions for the definitive study: yes, no immobilisation observed up to 1000 mg/L, therefore in the main study a limit test with the limit loading rate of 100 mg/L (nominal) was performed

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: none
- Other biological observations:
- Mortality of control: no
- Other adverse effects control: no
- Immobilisation of control: no
- Abnormal responses: no
- Any observations that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: no as WAF was performed

Results with reference substance (positive control):

Results for positive conctrol not reported.

Reported statistics and error estimates:

Not applicable as a limit test was performed

Table 1. Measured concentration by ICP-OES analysis (non-filtered)

Loading rate (mg/L)	Mean measured concentration (mg/L)
	0-hour	48-hour
Control	ND	ND
100	0.04(+/-)0.01	0.03(+/-)0.01

* ND : Not detected

Table 2. Measured concentration by ICP-OES analysis (filtered)

Loading rate (mg/L)	Mean measured concentration (mg/L)
	0-hour	48-hour
Control	ND	ND
100	< 0.02	< 0.02

* ND : Not detected

* 0.02 : Bottom limit of quantitation

Table 3. Cumulative immobility of Daphnia magna

Loading rate (mg/L)	Number of daphnia tested	Number of immobilized daphnia
		24-hour	48-hour
Control	20	0	0
100	20	0	0

Table 4. Symptoms on intoxication of the test substance to Daphnia magna

Loading rate (mg/L)	Symptoms of intoxication
	24-hour	48-hour
Control	NOR	NOR
100	NOR	NOR

* NOR : Normal

Validity criteria fulfilled:

not specified

Conclusions:

In a GLP-compliant Daphnia sp., Acute immobilisation limit test according to OECD 202 (adopted:13. April, 2004) the 24 and 48-hour EL50 and NOELR were determined to be >= 100 mg/L and 100 mg/L (nominal), respectively.

Executive summary:

A 48-hour Daphnia sp., Acute immobilisation test according to OECD Guideline 202 (adopted:13. April, 2004) with titanium dioxide was performed under static conditions and in compliance with the GLP principles. Because of the very low water solubility of titanium dioxide the test solutions were prepared by using Water Accommodated Fractions in accordance with OECD Guideline 23 (2000). Five daphnids (Daphnia magna) were exposed in four replicates to a limit loading rate of 100 mg test substance/L. In addition, a negative control (5 daphnids in 4 replicates) and a positive control with the reference substance Potassium dichromate were performed. The results of the test are expressed as loading rates: The 24 and 48-hour EL50 and NOELR were determined to be >= 100 mg/L and 100 mg/L (nominal), respectively.

Reference 4

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

For Read-Across Justification please refer to Section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

91.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Reference 5

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

not specified

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

not specified

GLP compliance:

not specified

Remarks:

not reported in OECD SIDS report

Specific details on test material used for the study:

- Name: non-nano-scale pigment Titanium dioxide
- Surface coating: no
- TiO2-content (%): 99.4
- Particle size (nm): 200-300
- Specific surface area (m2/g): 6

Analytical monitoring:

not specified

Details on sampling:

not specified

Vehicle:

not specified

Details on test solutions:

not reported

Test organisms (species):

Daphnia magna

Details on test organisms:

- Breeding temperature: 20(+/-) 2 °C
- Feed: fed daily with a suspension of the unicellular green alga Desmodesmus

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

not specified

Hardness:

total hardness: 2.02-2.86 mmol/L

Test temperature:

20(+/-) 2 °C

pH:

7.7-8.4

Dissolved oxygen:

not specified

Salinity:

not applicable

Conductivity:

not specified

Nominal and measured concentrations:

nominal concentration (mg/L): control, 1, 10, 100

Details on test conditions:

TEST SYSTEM
- Test vessel: not specified
- Material, size, headspace, fill volume: not specified
- Volume of solution: not specified
- No. of organisms per vessel: 5
- No. of vessels per concentration: 4
- No. of vessels per control: 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: not specified

OTHER TEST CONDITIONS
- Adjustment of pH: not specified
- Photoperiod: 16 hours of light and 8 hours of darkness
- Light quality: artificial light

EFFECT PARAMETERS MEASURED: mobility

RANGE-FINDING STUDY : not specified

Reference substance (positive control):

not specified

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

91.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

not reported

Results with reference substance (positive control):

not specified

Reported statistics and error estimates:

not reported

Validity criteria fulfilled:

not specified

Conclusions:

In a Daphnia sp. Acute Immobilisation Test with Daphnia magna according to OECD Guideline 202 the 48-hour EC50 and EC10 were determined to be >100 mg/L and 91.2 mg/L (nominal), respectively.

Executive summary:

A Daphnia sp. Acute Immobilisation Test according to OECD Guideline 202 was performed to assess the short-term toxicity of titanium dioxide to aquatic invertebrates. Five daphnids (Daphnia magna) in four replicates per treatment were exposed to nominal test item concentrations of 0 (control), 1, 10 and 100 mg/L. In result, the 48-hour EC50 and EC10 were determined to be >100 mg/L and 91.2 mg/L (nominal), respectively.

Reference 6

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

For Read-Across Justification please refer to Section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Reference 7

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

not specified

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

not specified

GLP compliance:

not specified

Specific details on test material used for the study:

Name : ultrafine TiO2

Analytical monitoring:

not specified

Details on sampling:

not specified

Vehicle:

not specified

Details on test solutions:

not specified

Test organisms (species):

Daphnia magna

Details on test organisms:

not specified

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

not specified

Hardness:

not specified

pH:

not specified

Dissolved oxygen:

not specified

Salinity:

not applicable

Conductivity:

not specified

Nominal and measured concentrations:

nominal concentrations : 0.1, 1.0, 10, and 100 mg/L

Details on test conditions:

Only one test chamber per treatment each with 10 daphnids was used (1 replicate).

Reference substance (positive control):

not specified

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

After 48 hours of exposure no immobility was observed for the test item concentrations of 0.1, 1.0, 10, and 100 mg/L.

Results with reference substance (positive control):

not specified

Reported statistics and error estimates:

not reported

Validity criteria fulfilled:

not specified

Conclusions:

In an Daphnia sp. Acute Immobilisation Test according to OECD Guideline 202, Daphnia magna was exposed to test item concentrations of 0.1, 1.0, 10, and 100 mg/L. In this study only one test chamber per treatment each with 10 daphnids was used (1 replicate). As a result, no immobility was observed in any treatment throughout the test duration of 48 hours. Therefore, the 48-hour EC50 was determined to be > 100 mg/L.

Reference 8

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

For Read-Across Justification please refer to Section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Effect conc.:

> 1 000 mg/L

Remarks on result:

other: not further specified

Reference 9

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

not specified

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Qualifier:

according to guideline

Guideline:

other: U.S. Environmental Protection Agency, Users guide: procedures for conducting Daphnia magna toxicity bioassays. EPA-660/8-87/011. March 1987

Qualifier:

according to guideline

Guideline:

other: American Society for testing and materials. Standard E729, Guide for conducting acute toxicity tests with fishes, macroinvertebrates and amphibians, 1986

GLP compliance:

yes

Specific details on test material used for the study:

- Name : Titanium dioxide
- Appearance : white powder

Analytical monitoring:

not specified

Details on sampling:

not specified

Vehicle:

not specified

Details on test solutions:

not specified

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Age at study initiation: not specified
- Stage and instar at study initiation: not specified
- Source: not specified
- Age of parental stock: not specified
- Feeding during test : not specified

ACCLIMATION
- Acclimation period: not specified

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES, INCLUDING CULTURING CONDITIONS: not specified

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

not specified

Hardness:

not reported

Test temperature:

not reported

pH:

not reported

Dissolved oxygen:

not reported

Salinity:

not applicable

Conductivity:

not reported

Nominal and measured concentrations:

not reported

Details on test conditions:

not reported

Reference substance (positive control):

not specified

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Remarks on result:

other: not further specified

Details on results:

not reported

Results with reference substance (positive control):

not specified

Reported statistics and error estimates:

The EC50 values were calculated by probit analysis.

Validity criteria fulfilled:

not specified

Conclusions:

In a Daphnia magna toxicity bioassay the 48-hour EC50 of titanium dioxide was determined to be > 1000 mg/L.

Description of key information

The study on short-term toxicity to aquatic invertebrates with diiron tetanium pentaoxide does not need to be conducted because the substance is highly insoluble in water, hence indicating that aquatic toxicity is unlikely to occur (study scientifically not necessary). However, by applying an analogue approach the 48-hour EC50 for the target substance was determined to be > 100 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

Non-submission justification

Diiron titanium pentaoxide was assessed in three guideline studies to be sparingly soluble in water (references 4.8-2, 4.8-3 and 4.8-1). In a worst case approach the water solubility of the test item was determined to be 2.715 µg/L at a temperature of 20 °C (please refer to the endpoint summary in IUCLID section 4.8). Furthermore, the maximum of the mono-modal particle size distribution was observed at approximately between 10 µm and 20 µm. The D10, D50 and D90 percentile were determined as L10 = 7.07 µm, L50 = 13.1 µm and L90 = 22.9 µm, respectively. Considering these physicochemical properties, TiFe2O5  is unlikely to cross biological membranes (please also refer to IUCLID section 7.1). Therefore, in accordance with the criteria given in column 2 of Annex VII to Regulation (EC) No 1907/2006 (REACH), the study on short-term toxicity to aquatic invertebrates is considered scientifically not necessary and was waived.

Nevertheless, information available for the read across source substances titanium dioxide (CAS 13463-67-7) and diiron trioxide (CAS 1309-37-1) is summarized below.

Titanium dioxide

Data from four guideline studies with the source substance titanium dioxide (bulk form) are publicly available.

A 48-hour Daphnia sp., Acute immobilisation test according to OECD Guideline 202 (adopted:13. April, 2004) with titanium dioxide was performed under static conditions and in compliance with the GLP principles. Because of the very low water solubility of titanium dioxide the test solutions were prepared by using Water Accommodated Fractions in accordance with OECD Guideline 23 (2000). Five daphnids (Daphnia magna) were exposed in four replicates to a limit loading rate of 100 mg test substance/L. In addition, a negative control (5 daphnids in 4 replicates) and a positive control with the reference substance Potassium dichromate were performed. The results of the test are expressed as loading rates: The 24 and 48-hour EL50 and NOELR were determined to be >= 100 mg/L and 100 mg/L (nominal), respectively (reference 6.1.3 -1). The study was classified to be reliable without restrictions (Klimisch 1).

Further, a reliable (Klimisch 2, reliable with restrictions) Daphnia sp. Acute Immobilisation Test according to OECD Guideline 202 was performed to assess the short-term toxicity of titanium dioxide to aquatic invertebrates (reference 6.1.3 -2). Five daphnids (Daphnia magna) in four replicates per treatment were exposed to nominal test item concentrations of 0 (control), 1, 10 and 100 mg/L. In result, the 48-hour EC50 and EC10 were determined to be >100 mg/L and 91.2 mg/L (nominal), respectively.

This result is supported by an additional Daphnia sp. Acute Immobilisation Test according to OECD Guideline 202. Daphnia magna was exposed to test item concentrations of 0.1, 1.0, 10, and 100 mg/L. In this study only one test chamber per treatment each with 10 daphnids was used (1 replicate). As a result, no immobility was observed in any treatment throughout the test duration of 48 hours. Therefore, the 48-hour EC50 was determined to be > 100 mg/L (reference 6.1.3 -3).

In another Daphnia magna toxicity bioassay the 48-hour EC50 of titanium dioxide was determined to be > 1000 mg/L. The study was regarded not assignable (Klimisch 4) as its documentation is not sufficient for assessment (reference 6.1.3 -4).

Key information on short-term toxicity to aquatic invertebrates provided in public ECHA REACH dossiers for the read across substances titanium dioxide and diiron trioxide

Titanium dioxide

In the public ECHA REACH dossier for titanium dioxide (last accessed on: 18 March 2020) it is concluded that dispersions of microsized tinanium dioxide are not acutely toxic to freshwater and marine invertebrates up to at least 1000 and 10,0000 mg/L (EC/LC50: > 1000 and > 10,000), respectively. Taking into account that microsized titanium dioxide is sparingly soluble in water, the substance is considered to be not acutely toxic to aquatic invertebrates up to its solubility limit.

Diiron trioxide

Referring to the public ECHA REACH dossier for the read across substance diiron trioxide (last accessed on: 18 March 2020) the observed 48-hour EC50 on Daphnia magna was found to be >/= 100 mg/L.

Conclusion

The study does not need to be conducted as diiron titanium pentaoxide is highly insoluble in water and unlikely to cross biological membranes, hence indicating that aquatic toxicity is unlikely to occur. This conclusion is supported by assessments for the structural analogues diiron trioxide (CAS 1309-37-1) and titanium dioxide (CAS 13463-67-7) demonstrating that short-term toxicity to aquatic invertebrates is not to be expected. Both source substances are neither classified for short-term (acute) nor long-term (chronic) aquatic toxicity according to Regulation (EC) No 1272/2008 (CLP).

Target and source substances are metal-containing inorganic oxides. The target substance diiron(III) titanium pentaoxide is a mixed oxide of titanium dioxide and diiron trioxide. The source substances share the common atoms Ti, O and Fe with the target substance and have very similar physicochemical properties. Therefore, based on an analogue approach, diiron titanium pentaoxide is also not considered acutely toxic to aquatic invertebrates. Additional data on short-term toxicity of diiron titanium pentaoxide to aquatic invertebrates are thus scientifically not necessary. Following a weight of evidence approach and based on the most reliable information for the source substance TiO2 (reference 6 .1.3-1) the EC50 for diiron titanium pentaoxide is determined to be > 100 mg/L.