Ferrosilicon - reaction mass of iron and iron disilicide and iron silicide and silicon

Bioaccumulation: aquatic / sediment

Administrative data

Endpoint:

bioaccumulation: aquatic / sediment

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Secondary literature sources and data

Data source

Reference

Reference 1

Reference Type:

review article or handbook

Title:

Trace elements in soils and plants

Author:

Kabata-Pandias, Alice

Year:

2000

Bibliographic source:

3th edition, CRC Press, London

Reference 2

Reference Type:

review article or handbook

Title:

Elements and their Compounds in the Environment: Occurrence, Analysis and Biological Relevance,

Author:

Merian, E., Anke, M., Ihnat, M. and Stoeppler, M.

Year:

2004

Bibliographic source:

Volume 1-3, Wiley-VCH,

Reference 3

Reference Type:

other:

Title:

SIDS dossier for 7782-63-0.

Author:

CERI

Year:

2005

Bibliographic source:

NITE CHRIP (Public database). National Institute of Technology and Evaluation. Chemicals Evaluation and Research Institute (CERI); Tokyo, Japan

Reference 4

Reference Type:

publication

Title:

The accumulation from water of 65Zn, 54Mn, 58Co and 59Fe by the mussel, Mytilus edulis.

Author:

Pentreath, R.J.

Year:

1973

Bibliographic source:

Journal of the Marine Biological Association of the United Kingdom. 53:1 127-14.

Materials and methods

Test material

Test material information

Constituent 1

Reference substance name:

various transition metals

IUPAC Name:

various transition metals

Applicant's summary and conclusion

Executive summary:

The main constituents of FeSi alloys are silicon and iron, both very common elements in the environment. Most living organisms contain at least trace quantities of silicon and iron. Bioaccumulation of Si and Fe and other significant constituent elements Sr, Ba, Zr and Ti is well or at least sufficiently known for hazard assessment purposes and no specific reasons have emerged to study the issue further in this context.

For naturally occurring inorganic substances such as metals, bioaccumulation is a complex issue, and many processes are available to modulate both the accumulation and potential toxic impact. The issue becomes even more complex if the substance under evaluation is a mixture of metals/elements. Adaptation and mechanisms to handle these common metals at systemic level exists to certain extent. Most species tend to regulate internal concentrations of these metals through active regulation, storage, or a combination of active regulation and storage over a wide range of environmental exposure conditions.

Siliconhas no tendency or a low intrinsic tendency for bioconcentration and bioaccumulation if taken up passively by organisms. Si compounds are so abundant in the environment that most living organisms contain at least trace quantities of silicon. For some species Si is an essential element taken up actively, while for others Si is not essential but it is still taken passively (Si transport and distribution follows that of water). In these cases it needs to be excreted or passivated in other ways. Many organisms such as diatom algae, radiolarians, flagellates and gastropods have silicate skeletal structures.

Iron is biologically essential metal and actively taken up by aquatic and terrestrial organisms. In one study bioaccumulation factors of 2756 – 9622 were measured for blue mussel (Mytilus edulis) when exposed to initial total iron concentration of 0.009 mg/l for 42 days at 10^oC (Pentreath (1973)). The results support a sequestering mechanism for active uptake of iron from seawater into the organism. In a study on ferrous sulfate heptahydrate, it was shown that BCF values were less than 20 for fishCyprinus sp., in a 28 day study using flow-through (CERI, 2001).

Strontium (Sr)andbarium(Ba)are very common in the environment and therefore found also in biota. Sr is the most abundant trace element in ocean water at the average concentration of 8 mg/L (Merian 2004). It has been observed that Sr ingested and absorbed via diet partitions rapidly to skeletons of vertebrate animals and shells of aquatic invertebrates. Sr is only slowly removed in the normal processes of metabolism. Fish may contain > 100 mg/kg Sr (whole fish). Some aquatic plants, brown algae and calcareous red algae may concentrate strontium from sea water up to 1400 mg/kg (dw).

Surface fresh waters contain 0.007-15 mg/l barium, sea water only ca. 5 µg/l since BaSO₄is precipitated. Barium levels have been measured to be between 4 and 88 mg/kg (dw) in invertebrates (Merian, 2004). Similar to strontium, Ba is also distributed mainly to skeletons.

Zirconium(Zr) is present in the environment mainly in the forms of ZrO₂, Zr(OH)₄and Zr(OH)₅^-. The average Zr concentration in fresh water is 2-20 µg/l and <1-20 µg/l in sea water. It is unclear if these concentrations are representing true dissolved values or total concentrations. Zr is not reported to have any bioaccumulation potential to aquatic species. In comparison to terrestrial plants, Zr is known to have negative accumulation potential to some aquatic species (Merian 2004).

Titanium (Ti) is not recorded to bioconcentrate remarkably. Some diatoms are known to bioconcentrate titanium in much higher extent than other algal species (Kabata-Pandias, 2000). Dataset is still scarce.