Chrome tin orchid cassiterite

Short-term toxicity to aquatic invertebrates

Administrative data

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

the study does not need to be conducted because the substance is unlikely to cross biological membranes, hence indicating that aquatic toxicity is unlikely to occur

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
According to Annex VII, Column 2, Section 9.1.1. of Regulation (EC) 1907/2006, testing for short-term toxicity on invertebrates 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”.

Chrome tin orchid cassiterite 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. For trivalent chromium and iron ions, the acute and chronic ERVs are above 1 mg/L, respectively, and a concern for short-term (acute) and 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 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.” Further, ”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 an acute and chronic aquatic hazard potential for soluble trivalent chromium and iron ions and the fact that dissolved chromium and iron concentrations were below the LOD of 0.5 µg/L after 7 and 28 days at pH 6 in the T/D test, respectively, it can be concluded that the substance chromium iron hematite is not sufficiently soluble to cause short- or long-term toxicity at the level of the acute or chronic ERVs (expressed as EC50/LC50 or NOEC/EC10, respectively). Hence, the pigment can be considered as environmentally and biologically inert during short- and long-term exposure. The poor solubility of Chrome tin orchid cassiterite is expected to determine its behaviour and fate in the environment, and subsequently its potential for ecotoxicity.

Proprietary studies are not available for Chrome tin orchid cassiterite. The poorly soluble substance Chrome tin orchid cassiterite is evaluated by comparing the dissolved metal ion levels resulting from the transformation/dissolution test after 7 days at a loading rate of 1 mg/L with the lowest acute ecotoxicity reference values (ERVs) as determined for the (soluble) metal ions. The acute ERVs are based on the lowest EC50/LC50 values for algae, invertebrates and fish and were obtained from the Metals classification tool (MeClas) database as follows: For trivalent chromium and tin ions, the acute ERVs are above 1 mg/L (>100 mg Cr3+/L; 9.8 mg Sn/L) and thus 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 chromium and tin ions and the fact that the maximum quantified concentrations of chromium and tin after 7 days T/D tests at pH 6 and 8 (0.042 µg Cr/L and 2.873 µg Sn/L at pH 8) remained well below the respective lowest acute ERVs (>100 mg Cr3+/L; 9.8 mg Sn/L), it can be concluded that the substance Chrome tin orchid cassiterite is not sufficiently soluble to cause short-term toxicity at the level of the acute ERVs (expressed as EC50/LC50).


In accordance with Figure IV.4 “Classification strategy for determining acute 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 Chrome tin orchid cassiterite is poorly soluble and does not meet classification criteria for acute (short-term) aquatic hazard.

Chrome tin orchid cassiterite is poorly soluble and unlikely to cross biological membranes. In accordance with Annex VII, Column 2, Section 9.1.1. of Regulation (EC) 1907/2006, testing for short-term toxicity to invertebrates is not necessary.