Ferric ammonium citrate

Bioaccumulation: aquatic / sediment

Description of key information

Iron: In a study of ferrous sulfate heptahydrate, it was shown that BCF values were less than 20 for Cyprinus sp., in a 28 day study.

Citrate: Low potential for bioaccumulation

Ammonium: Low potential for bioaccumulation

Sulfate: Low potential for bioaccumulation

Additional information

No studies are available for the bioaccumulation of reaction mass of ammonium iron (III) citrate and ammonium sulfate. However, ammonium iron (III) citrate and ammonium sulfate are both expected to dissociate under environmentally relevant conditions (see Section 1.3 of the CSR). Therefore, it is appropriate to read-across data relevant to the bioaccumulation of iron, citrate, ammonium and sulfate. Further details may be found in an expert report (Peter Fisk Associates, 2012) attached in Section 13 of the IUCLID 5 dossier.

Iron (III)

The available studies are all for iron salts which dissociate readily upon dissolution in water. The key study: CERI 2001 studied the bioconcentration of iron using an appropriate study guideline (OECD 305- Flow through test). A bioconcentration factor of <20 was obtained for the test substance. In another supporting study (Andersen 1997), a bioconcentration factor of 0.135 – 0.917 was obtained for iron uptake in the fry (post yolk absorption stage) of Brown Trout. The level of iron in the intact eggs showed a dose-dependent increase following treatment. The levels of the embryo in the egg membranes did not significantly differ between treated groups and controls. About 5% of the accumulated tracer was observed in the embryo after 4 days of exposure to 59 -Fe. Iron accumulation in the fry was suggested to increase with development of the gills. The bioconcentration factor decreases with increasing iron exposure. Iron is a bioessential trace element for organisms which includes microorganism, plants and animals. It plays an important role in biological processes. The uptake of iron into the cells of organisms is strictly controlled by homeostatic process.

Citrate

An estimated BCF of 3.2 (log BCF = 0.5) was obtained for citric acid using BCFBAF program which forms part of the Syracuse EPIWEB suite. The estimated value of citric acid is well below the cut off value of BCF ≥ 500 that is considered to indicate potential for bioaccumulation; the result indicates that citric acid is not expected to bioaccumulate.

Citrate is found in all eukaryotic cells as an intermediate of the TCA cycle, which is part of the basic metabolic pathway that generates useable energy from carbohydrates, proteins and fats. Citric acid is formed and broken down in the course of this cycle at very high rates. The weight of evidence of the role in cell metabolism, ready biodegradability and low estimated BCF indicate that citrate is extremely unlikely to bioaccumulate.

Ammonium

The ammonium ion upon release into the environment would enter natural nitrogen cycles in air, soil and water. Based on the high water solubility and the ionic nature, ammonium is not expected to bioaccumulate to a significant extent.

Sulfate

The sulfate ion upon release into the environment would enter natural sulfur cycles in air, soil and water. Based on the high water solubility and the ionic nature, sulfate is not expected to bioaccumulate to a significant extent.