Manganese alumina pink corundum

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

long-term toxicity to aquatic invertebrates

Data waiving:

study technically not feasible

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
Manganese alumina pink corundum 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 available transformation/dissolution data (Grané, 2010) that indicate a very low release of pigment components at pH 6, the pH that maximises dissolution. At a loading of 1 mg/L and pH 6, dissolved concentrations of 0.29 and 0.042 µg/L aluminium and 10.66 and 8.91 µg/L manganese were measured after 7 and 28 days, respectively. Thus, the rate and extent to which Manganese alumina pink corundum produces soluble (bio)available ionic and other aluminium- and manganese-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 Manganese alumina pink corundum is expected to determine its behaviour and fate in the environment, and subsequently its potential for ecotoxicity.

Proprietary studies are not available for Manganese alumina pink corundum. The poorly soluble substance Manganese alumina pink corundum is evaluated by comparing the dissolved metal ion levels resulting from the transformation/dissolution test after 28 days at a loading rate of 1 mg/L with the lowest chronic ecotoxicity reference values (ERVs) as determined for the (soluble) metal ions. The ERVs are based on the lowest NOEC/EC10 values for algae, invertebrates and fish. In accordance with the Classification and Labelling Committee in 1999 (see report 013-003-00-7 submitted to the C&L Committee, 1999) 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). Due to the lack of a chronic hazard potential for dissolved aluminium ions, only manganese concentrations and the respective chronic ERV are taken into account. The chronic ERV for manganese of 550 µg Mn/L was obtained from the Metals classification tool (MeClas) database. The dissolved manganese concentration of 8.91 µg Mn/L in the T/D test after 28 days at pH 6 is significantly lower than the corresponding lowest long-term ERV of 550 µg Mn/L. Hence, the substance Manganese alumina pink corundum 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.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 Manganese alumina pink corundum is poorly soluble and does not meet classification criteria for 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”.

Manganese alumina pink corundum is poorly soluble and unlikely to cross biological membranes. Hence, Manganese alumina pink corundum can be considered environmentally and biologically inert during aquatic exposure (please see above). For a highly insoluble substance such as Manganese alumina pink corundum, 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 Manganese alumina pink corundum is not sufficiently soluble to cause long-term toxicity at the level of the chronic ERVs (expressed as NOEC/EC10), it is neither technically possible in accordance with Annex XI, Section 2 of Regulation (EC) 1907/2006 nor scientifically justified to conduct any further aquatic toxicity study, including long-term toxicity to invertebrates with Manganese alumina pink corundum.