[No public or meaningful name is available]

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING

According to Annex VII, Column 2, Section 9.1.2. of Regulation (EC) 1907/2006, the test for growth inhibition of aquatic plants does not need to be conducted “if there are mitigating factors indicating that aquatic toxicity is unlikely to occur, for instance if the substance is highly insoluble in water or the substance is unlikely to cross biological membranes”.

Titanium, iron and aluminium pseudobrookite and rutile can be considered environmentally and biologically inert due to the characteristics of the synthetic process (calcination at a high temperature of approximately 1000°C), rendering the substance to be of a unique, stable crystalline structure in which all atoms are tightly bound and not prone to dissolution in environmental and physiological media. This assumption is supported by transformation/dissolution data (Knopf, 2018) that indicate a very low release of pigment components at pH 6 and 8. Transformation/dissolution tests of titanium, iron and aluminium pseudobrookite and rutile at a loading of 1 mg/L and pH 6 resulted after 7 days in aluminium concentrations below the LOD of 0.161 µg Al/L, iron concentrations of 1.34 µg Fe/L and titanium concentrations below the LOQ of 0.123 µg Ti/L. After 28 days at pH 6 aluminium concentrations remained below the LOD of 0.341 µg Al/L, while the dissolved iron and titanium concentrations amounted to 0.357 µg Fe/L and 0.063 µg Ti/L, respectively. T/D tests at pH 8 resulted after 7 days in dissolved aluminium and iron concentrations below the LODs of 0.161 µg Al/L and 0.035 µg Fe/L, respectively. Titanium concentrations remained below the respective LOQ of 0.123 µg Ti/L. After 28 days at pH 8, the dissolved aluminium concentrations amounted to 0.533 µg Al/L, while the iron concentrations remained below the LOD of 0.085 µg Fe/L and the titanium concentrations below the LOQ of 0.123 µg Ti/L. Thus, the rate and extent to which titanium, iron and aluminium pseudobrookite and rutile produces soluble (bio)available ionic and other aluminium-, iron- and titanium-bearing species in environmental media is limited. Hence, the pigment can be considered as environmentally and biologically inert during short- and long-term exposure. The poor solubility of titanium, iron and aluminium pseudobrookite and rutile is expected to determine its behaviour and fate in the environment, and subsequently its potential for ecotoxicity.

Proprietary studies are not available for titanium, iron and aluminium pseudobrookite and rutile. The poorly soluble substance titanium, iron and aluminium pseudobrookite and rutile is evaluated by comparing the dissolved metal ion levels resulting from the transformation/dissolution test after 7 and 28 days at a loading rate of 1 mg/L with the lowest acute and chronic ecotoxicity reference values (ERVs) as determined for the (soluble) metal ions. The acute and chronic ERVs are based on the lowest EC50/LC50 or NOEC/EC10 values for algae, invertebrates and fish, respectively, and were obtained from the Metals classification tool (MeClas) database as follows: The acute ERVs of aluminium (1,040 µg Al/L at pH 6 and 3,390 µg Al/L at pH 8), iron (>100 mg Fe/L) and titanium are above 1 mg/L and a concern for short-term (acute) toxicity was not identified (no classification). According to ECHA Guidance on the Application of the CLP Criteria (Version 5.0, July 2017), “Where the acute ERV for the metal ions of concern is greater than 1 mg/L the metals need not be considered further in the classification scheme for acute hazard.” Due to the lack of an acute aquatic hazard potential of aluminium, iron and titanium ions and the fact that almost all dissolved metal concentrations, except the dissolved iron concentration at pH 6 (1.34 µg Fe/L), remained below the respective LODs (< 0.161 µg Al/L, < 0.035 µg Fe/L) or LOQs (< 0.123 µg Ti/L) after 7 days T/D tests at pH 6 and 8, it can be concluded that the substance titanium, iron and aluminium pseudobrookite and rutile is not sufficiently soluble to cause short-term toxicity at the level of the acute ERVs (expressed as EC50/LC50).

Regarding the long-term toxicity, a chronic ERV for dissolved aluminium ions has not been derived since a concern for long-term (chronic) toxicity of aluminium ions was not identified (no classification), according to the Classification and Labelling Committee in 1999 (see report 013-003-00-7 submitted to the C&L Committee, 1999). The chronic ERVs of iron and titanium are above 1 mg/L, and a concern for long-term (chronic) toxicity was not identified (no classification). According to ECHA Guidance on the Application of the CLP Criteria (Version 5.0, July 2017), ”Where the chronic ERV for the metal ions of concern corrected for the molecular weight of the compound (further called as chronic ERV compound) is greater than 1 mg/L, the metal compounds need not to be considered further in the classification scheme for long-term hazard.” Due to the lack of a chronic aquatic hazard potential of aluminium, iron and titanium ions and the fact that 28 days T/D tests at a loading of 1 mg/L at pH 6 and 8, resulted in maximum quantified metal concentrations of 0.533 µg Al/L (at pH 8), 0.357 µg Fe/L (at pH 6) and 0.063 µg Ti/L (at pH 6), while concentrations at the alternate pH remained below the LOD or LOQ, it can be concluded that the substance titanium, iron and aluminium pseudobrookite and rutile is not sufficiently soluble to cause long-term toxicity at the level of the chronic ERVs (expressed as NOEC/EC10).

In accordance with Figure IV.4 “Classification strategy for determining acute aquatic hazard for metal compounds” and Figure IV.5 „Classification strategy for determining long-term aquatic hazard for metal compounds “of ECHA Guidance on the Application of the CLP Criteria (Version 5.0, July 2017) and section 4.1.2.10.2. of Regulation (EC) No 1272/2008, the substance titanium, iron and aluminium pseudobrookite and rutile is poorly soluble and does not meet classification criteria for acute (short-term) and chronic (long-term) aquatic hazard.

In accordance with Annex XI, Section 2 of Regulation (EC) 1907/2006, “Testing for a specific endpoint may be omitted, if it is technically not possible to conduct the study as a consequence of the properties of the substance”.
Titanium, iron and aluminium pseudobrookite and rutile is poorly soluble and unlikely to cross biological membranes. Hence, Titanium, iron and aluminium pseudobrookite and rutile can be considered environmentally and biologically inert during aquatic exposure (please see above). For a highly insoluble substance such as Titanium, iron and aluminium pseudobrookite and rutile, it may neither be possible nor relevant to try and conduct aquatic toxicity tests, as it is difficult to maintain a quantifiable and constant concentration of the substance in the environmental test medium. In accordance with the generic testing recommendations in the “Executive summary of the MISA 2 workshop (https://echa.europa.eu/misa)” for difficult to test substances, “The Water Accommodated Fraction (WAF) method (see REACH and OECD guidance on difficult to test substances), should not be used for metals. The reason is that this method often uses nominal loadings and lacks the pH and surface relationships necessary to estimate the potential hazard. Direct aquatic ecotoxicity testing of metals and SSMCs is in principle not recommended. However, if used or needed (e.g. for complex materials like UVCBs) then it should be conducted based on the dissolved fraction(s) of the T/D medium, at the appropriate pH (pH that dilutes the most).”
Since the substance Titanium, iron and aluminium pseudobrookite and rutile is not sufficiently soluble to cause toxicity at the level of the acute and chronic ERVs (expressed as EC/LC50 or EC10/NOEC), it is not technically possible in accordance with Annex XI, Section 2 of Regulation (EC) 1907/2006 to conduct any further aquatic toxicity study, including testing for growth inhibition of aquatic plants with Titanium, iron and aluminium pseudobrookite and rutile.

Titanium, iron and aluminium pseudobrookite and rutile is poorly soluble and unlikely to cross biological membranes. In accordance with Annex VII, Column 2, Section 9.1.2. of Regulation (EC) 1907/2006, testing for growth inhibition of aquatic plants is not necessary.

Cross-reference

Reason / purpose for cross-reference:

data waiving: supporting information

Reference

Endpoint:

transformation / dissolution of metals and inorganic metal compounds

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-08-08 to 2017-10-20

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Series on Testing and Assessment No. 29 (23-Jul-2001): Guidance document on transformation/dissolution of metals and metal compounds in aqueous media

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

signed 2016-05-31

Type of method:

flask method

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.341 µg/L

Element analysed:

Al

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH = 6, separation of solid phase by filtration 0.2 µm

Remarks on result:

other:

Remarks:

conc. of all replicates < LOD: 0.341 µg/L

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

0.533 µg/L

Element analysed:

Al

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH = 8, separation of solid phase by filtration 0.2 µm

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.161 µg/L

Element analysed:

Al

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH = 6, separation of solid phase by filtration 0.2 µm

Remarks on result:

other:

Remarks:

conc. of all replicates < LOD: 0.161 µg/L

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.161 µg/L

Element analysed:

Al

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH = 8, separation of solid phase by filtration 0.2 µm

Remarks on result:

other:

Remarks:

conc. of all replicates < LOD: 0.161 µg/L

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.161 µg/L

Element analysed:

Al

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

pH = 6, separation of solid phase by filtration 0.2 µm

Remarks on result:

other:

Remarks:

conc. of all replicates < LOD: 0.161 µg/L

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.161 µg/L

Element analysed:

Al

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

pH = 8, separation of solid phase by filtration 0.2 µm

Remarks on result:

other:

Remarks:

conc. of all replicates < LOD: 0.161 µg/L

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

0.357 µg/L

Element analysed:

Fe

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH = 6, separation of solid phase by filtration 0.2 µm

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.085 µg/L

Element analysed:

Fe

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH = 8, separation of solid phase by filtration 0.2 µm

Remarks on result:

not determinable

Remarks:

not distinguishable from blank

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

1.34 µg/L

Element analysed:

Fe

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH = 6, separation of solid phase by filtration 0.2 µm

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.035 µg/L

Element analysed:

Fe

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH = 8, separation of solid phase by filtration 0.2 µm

Remarks on result:

other:

Remarks:

conc. of all replicates < LOD: 0.035 µg/L

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.035 µg/L

Element analysed:

Fe

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

pH = 6, separation of solid phase by filtration 0.2 µm

Remarks on result:

other:

Remarks:

conc. of replicates < LOD: 0.035 µg/L

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.035 µg/L

Element analysed:

Fe

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

pH = 8, separation of solid phase by filtration 0.2 µm

Remarks on result:

other:

Remarks:

conc. of all replicates < LOD: 0.035 µg/L

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

0.063 µg/L

Element analysed:

Ti

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH = 6, separation of solid phase by filtration 0.2 µm

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.123 µg/L

Element analysed:

Ti

Loading of aqueous phase:

1 mg/L

Incubation duration:

28 d

Test conditions:

pH = 8, separation of solid phase by filtration 0.2 µm

Remarks on result:

other:

Remarks:

conc. of all replicates at least < LOQ: 0.123 µg/L

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.123 µg/L

Element analysed:

Ti

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH = 6, separation of solid phase by filtration 0.2 µm

Remarks on result:

other:

Remarks:

conc. of all replicates at least < LOQ: 0.123 µg/L

Key result

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

< 0.123 µg/L

Element analysed:

Ti

Loading of aqueous phase:

1 mg/L

Incubation duration:

7 d

Test conditions:

pH = 8, separation of solid phase by filtration 0.2 µm

Remarks on result:

other:

Remarks:

conc. of all replicates at least < LOQ: 0.123 µg/L

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

0.103 µg/L

Element analysed:

Ti

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

pH = 6, separation of solid phase by filtration 0.2 µm

Type of test:

full transformation/dissolution test - metals and sparingly soluble metal compounds

Mean dissolved conc.:

0.04 µg/L

Element analysed:

Ti

Loading of aqueous phase:

1 mg/L

Incubation duration:

24 h

Test conditions:

pH = 8, separation of solid phase by filtration 0.2 µm

Details on results:

Solution pH, oxygen concentrations, temperature
The temperature of the thermostatically controlled room was recorded with a data logger. The mean temperature was 21.3 ± 0.3 °C. The solution pH remained relatively constant for the pH 6 treatment for the method blank vessels (6.15 – 6.37) as for the sample vessels (5.93 – 6.37).
Oxygen levels in all test vessels pH 6 were in the range recommended by the OECD Test Guidance 29 during the test: above 70 % of oxygen saturation at 8.5 mg/L (70 % of 8.5 mg/L = 6 mg/L). The solution pH for the pH 8 treatment showed a decrease of the pH during the test in the method blanks as well as in the sample vessels. In the test item vessels the pH was in the range of 7.64 – 7.93 and in method blank vessels the pH was in the range of 7.66 – 7.84. Oxygen levels in all test vessels pH 8 were in the range recommended by the OECD Test Guidance 29 during the test: above 70 % of oxygen saturation at 8.5 mg/L (70 % of 8.5 mg/L = 6 mg/L)

Analytical measurements: Within and between vessel variations of elemental concentrations (Fe, Ti, Al)
Within and between vessel variations are not always in compliance with the guidance for the tests. For these samples the observed variations of > 20 % (between-vessel) or > 10 % (within-vessel) are probably due to the low dissolution and the majority of measurements being close to – or below – the respective quantification limit of the method

Method validation summary (ICP-OES)

Limits of detection (LODs), limits of quantification (LOQs) and correlation coefficients (r)

Limits of detection (LOD) within all measurement series: 0.161 -0.341 μg Al / L, 0.035 - 0.085 µg / L Fe

Limits of quantification (LOQ) within all measurement series: 0.482 - 1.02 μg Al / L, 0.106 - 0.255 µg / L Fe

Correlation coefficients (r) within all measurement series: > 0.999926 (Al calibration), > 0.999868 (Fe calibration)

Mean recovery of fortified samples (concentration range 6 - 160 µg, n > 5): 95,2 - 119 % (Al fortification), 95 - 108 % (Fe fortification)

Mean recovery for certified reference material TMDA-52.4 (lot no. 0615, Environment Canada): 99.9 - 104 % (Al measurement, n = 15), 98.4 - 103 % (Fe measurement, n = 13)

date	Chosen wavelength [nm]	LOD (µg/L)	LOQ (µg/L)	correlation coefficient	Sum of quality assurance samples	Recovery of quality assurance samples [%]
August 17, 2017; measurement of test samples (24 h and 7 d) and method blank samples (24 h and 7 d) – pH 6 and 8	Al: 167.019* Fe: 238.204*	Al: 0.161 Fe: 0.035	Al: 0.482 Fe: 0.106	Al: 0.999926 Fe: 0.999868	Al: 17 Fe: 17	Al: 88.2 Fe: 88.2

date	Chosen wavelength [nm]	LOD (µg/L)	LOQ (µg/L)	correlation coefficient	Sum of quality assurance samples	Recovery of quality assurance samples [%]
September 29, 2017; measurement of test samples (28 d) and method blank samples (28 d)	Al: 167.019* Fe: 238.204*	Al: 0.341 Fe: 0.085	Al: 1.02 Fe: 0.255	Al: 0.999974 Fe: 0.999940	Al: 26 Fe: 26	Al: 88.5 Fe: 92.3

date	Chosen wavelength [nm]	LOD (µg/L)	LOQ (µg/L)	correlation coefficient	Sum of quality assurance samples	Recovery of quality assurance samples [%]
October 20, 2017; measurement of mass balance samples – filters and test vessels pH 6 and 8	Al: 394.401* Fe: 260.709* Ti: 307.866*	Al: 2.16 Fe: 0.300 Ti: 0.149	Al: 6.48 Fe: 0.900 Ti: 0.448	Al: 0.999942 Fe: 0.999965 Ti: 0.999923	Al: 21 Fe: 21 Ti: 21	Al: 81.0 Fe: 95.5 Ti: 100

Method validation summary (ICP-MS)

Limits of detection (LODs), limits of quantification (LOQs) and correlation coefficients (r)

Limits of detection (LOD) within all measurement series: 0.041 μg Ti / L.

Limits of quantification (LOQ) within all measurement series: 0.123 μg Ti / L.

Correlation coefficients (r) within all measurement series: > 0.9997

Recovery of fortified samples (n = 4): 106 -110 %

Mean recovery of certified reference material TMDA-52.4 (lot no. 0615, Environment Canada): 102% (n=5)

Conclusions:

The transformation/dissolution test (OECD Series on Testing and Assessment Number 29, 2001) of "Titanium, iron and aluminium pseudobrookite and rutile (Pigment Black 12)" at a loading of 1 mg/L at pH 6 and 8, performed for 28d, resulted in maximum quantified Al concentrations of 0.533 µg/L (pH = 8, 28d), maximum Fe concentrations of 0.357 µg/L (pH = 6, 28d) als well as maximum Ti concentrations of 0.063 µg/L (pH = 6, 28d). Thus, the extent to which "Pigment Titanium, iron and aluminium pseudobrookite and rutile (Pigment Black 12)" can produce soluble available ionic and other metal-bearing species in aqueous media is limited.