Reaction mass of calcium hydrogen phosphonate and dialuminium tricalcium hexaoxide

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

fish early-life stage toxicity

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Additional information

In accordance with REACH Regulation, Annex IX, 9.1.6, column 2, a long-term study on fish does not need to be conducted. A test for long-term toxicity on fish is only required, if the chemical safety assessment according to REACH Regulation, Annex I, indicates the need to investigate further the effects on aquatic organisms. The choice of the appropriate test(s) depends on the results of the chemical safety assessment:

A reliable, relevant and adequate study according to OECD Guideline 203 and EU method C-1 is available. The 96-h LC50 for carp (Cyprinus carpio) is 409 mg/L (95 % confidence interval: 309 to 541 mg/L). The test was run by adding 97, 174, 309, 541, and 1010 mg/L. Noticed toxicity at>541 mg/L was most probably triggered by a pH effect. Dissociation of the reaction mass under the conditions of OECD Guidelines 112 or 105, resulted in an pKa of 10.1 and pH of 11.4, respectively. The substance does only comprise of common environmental elements – calcium, phosphate and aluminium. A temporary pH effect as toxicodynamic reason for aquatic toxicity of alkaline substances dissolving in common environmental constituents has been discussed in detail in the EU Risk Assessment on sodium hydroxide and in several OECD HPV SIDS documents on alkaline inorganic substances. In general, natural waters do have a sufficient buffering capacity to overcome this effect (c.f. EU RAR sodium hydroxide, 2007; http://echa.europa.eu/documents/10162/0ded9c53-4082-405b-b09a-e16e57e158af ). Therefore, substance "reaction mass of calcium hydrogen phosphonate and dialuminium tricalcium hexaoxide" is not expected to have a relevant intrinsic toxic activity to aquatic organisms and PNECs were not derived.

Further on, the substance does not fulfill the PB or vPvB criteria. The concept of “biodegradability” has been developed for organic substances and is not applicable to inorganic substances. Notwithstanding, for classification of chronic aquatic effects and the PBT assessment information on degradation is needed. As a surrogate approach for assessing “degradability” of inorganic substances, the concept of “removal from the water column” has been developed to assess whether or not a respective metal ion, or inorganic substance would remain present in the water column upon addition (and thus, be able to exert a chronic effect) or would be rapidly removed from the water column. In this concept, “rapid removal” (defined as >70 % removal within 28 days) can be considered equivalent to “rapid degradation”. For structurally related substances to substance "reaction mass of calcium hydrogen phosphonate and dialuminium tricalcium hexaoxide" - so called nanoclays - the environmental fate has been assessed on behalf of a national authority. In consideration of this assessment, most probably, if released to the environment, the inorganic, sparingly soluble crystalline solid of lamellar clay mineral (hydrocalumite)-like substance will end up in the sediment or soil compartment by sedimentation comparable to natural clay minerals. This fate is not expected to result in any negative environmental impact (c.f. G.E. Batley and M.J. McLaughlin CSIRO Niche Manufacturing Flagship Report, Fate of Manufactured Nanomaterials in the Australian Environment, prepared for the Australian Department of the Environment, Water, Heritage and the Arts (March 2010), available via Internet available via Internet (https://www.environment.gov.au/system/files/pages/371475a0-2195-496d-91b2-0a33f9342a6d/files/manufactured-nanomaterials.pdf).

Transformation by normal environmental processes (e.g. diagenesis or dissolution) is not expected to result in any negative environmental impact either, as the substance does only comprise of nonhazardous common environmental elements. Calcium and phosphate are essential for almost all living organisms including fresh- and saltwater fish and natural constituents of their habitats. Aluminium as most abundant metallic element of the earth´s crust, and thus together with the further moieties of the reaction mass also a natural component in environmental habitats. Thus, "reaction mass of calcium hydrogen phosphonate and dialuminium tricalcium hexaoxide" is considered as equivalent to being ‘rapidly degradable‘ in the context of classification for chronic aquatic effects and the PBT assessment. Based on the physicochemical properties, substance "reaction mass of calcium hydrogen phosphonate and dialuminium tricalcium hexaoxide" can be expected not to have a relevant potential for bioaccumulation at all. Data on partition coefficient n-octanol/water are not available as the substance is inorganic. However, measurement of solubility in standard fat HB 307 indicates on missing affinity to organic material. Further on, if dissoluted in water, the dissoluted moieties - calcium, phosphate, aluminium - are not considered to be bioaccumulative. As normal constituents of fish they are effectively processed and regulated in the body by natural physiological mechanisms.

Furthermore, the use of the substance on workplaces is controlled and widespread exposure to the environment is not expected. In service life, the substance is embedded in polymer matrices from which there is no release of substance “reaction mass of calcium hydrogen phosphonate and dialuminium tricalcium hexaoxide”.

In conclusion, substance "reaction mass of calcium hydrogen phosphonate and dialuminium tricalcium hexaoxide" is not classified for aquatic toxicity and not considered to be PBT/vPvB. Additional chronic testing is not required to refine this assessment. Further long-term toxicity testing on fish is therefore not triggered and this data requirement is waived in accordance with REACH Regulation, Annex IX, 9.1.6, column 2.