Registration Dossier

Administrative data

Endpoint:
hydrolysis
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The structure of iron ore pellets consists essentially of iron oxide grains. The bonding of the grains occur by oxide bridging, recrystallisation of hematite and to a lesser extent by the formation of fused silicate phases. Since silicates are inert and no effect on the environment is expected, the endpoints in Chapters 5 and 6 are based on the effects of iron as a worst case in these substances. More information on the justification of read across can be found in the attached document in the endpoint summaries of section 5 and 6.
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:

Data source

Materials and methods

Results and discussion

Applicant's summary and conclusion

Conclusions:
Under REACH (ECHA 2008, Chapter R.7B – Endpoint Specific Guidance), the term ‘hydrolysis’ refers to the “decomposition or degradation of a chemical by reaction with water”, and this as a function of pH (i.e., abiotic degradation). The need for testing may be waived if “the substance is highly insoluble in water), or if “the substance is readily biodegradable”. The latter property of a substance assumes a rapid mineralization of the substance and therefore hydrolysis tests will provide little information. In the case of the current substance ( [Fe-salt]), the chemical safety assessment will be based on elemental metal concentrations, regardless of their (pH-dependent) speciation in the environment. Hence, as the assessment is based on the element concentration (i.e., [Fe]), physicochemical processes like decomposition and degradation by reaction with water are not relevant. Formation of different [Fe]-hydroxides may occur, but the chemical assessment will not make any differentiation among the different [Fe]-species (pooling of different speciation forms). This elemental-based assessment (pooling all speciation forms together) can be considered as a worst-case assumption for the chemical assessment. In general, (abiotic) degradation is an irrelevant process for inorganic substances that are assessed on an elemental basis.