Diiron tris(sulphate)

Toxicity to aquatic plants other than algae

Description of key information

No relevant effects

Additional information

This endpoint is covered by the category approach for soluble iron salts (please see the section on physical and chemical properties for the category justification/report format). 

Testing for this endpoint has been waived in accordance with column 2 and Annex XI, part 1 and 2, restrictions.

Information from Literature Searches and earlier Assessment Approaches

The literature reviews of Vangheluwe & Versonnen (2004), Johnson et al. (2007) and OECD (2007) revealed some data. The results of the studies, selected as “reliable” by the respective authors are listed in the following tables. Nonetheless the experiments must be rated “not reliable” (Klimisch 3) according to the Klimisch et al. (1997) scale due to methodological objections against testing of aquatic organisms as concluded in the beginning of this chapter (section „Ecotoxicological information“). True, intrinsic toxicity of iron kations in aerobic aquatic test organisms cannot be determined in studies when the solubility of the dissolved ferric kation (as the ferrous form will readily be oxidized to ferric species) is exceeded. None of the experiments found effects at such low levels (depend on pH, section “water solubility”). Notwithstanding the methodological objections formally expressed in the waiving argument for the standard aquatic test organisms, the following data are mentioned for completeness.

Freshwater species:

Table: Data from the EURAS critical review (Vangheluwe & Versonnen 2004, table 5, p 21)

Test substance	Test organism	Test medium	Test conditions	Nominal / Measured	Duration	Endpoints	EC50 [mg/L]	Reference	Reliability
Fe3+	Lemna minor	deionized water	pH: 7.5; T: 27	N	4 days	growth	3.7	Wang 1986	R3

N: Nominal concentration

R3: Not reliable according to the authors (set out in chapter 3.2 of their publication)

T: Temperature [°C]

Table: Acute aquatic toxicity data on Macrophyta according to Johnson et al. (2007, Table 2.6, p 22)

Scientific name	Common name	Endpoint	Effect	Test duration [days]	Concentration [mg /L]	Exposure	Toxicant analysis	Comments (Author's Reliability)	Reference
Lemna minor	Lesser duckweed	EC50	Growth	4	3.7	s	n	As FeCl3; pH 7.5 (R3)	Wang 1968
Spriodela polyrrhiza	Greater duckweed	NOEC	Growth	7	16	s	n	As FeCl3; pH 7.5 (R3)	Sinha et al 1994

Exposure: s = static; ss = semi-static; f = flow-through

Toxicant analysis: y = measured; n = not measured.

R3: Not reliable according to the authors (set out in Annex 1, p 56 of their publication)

Table: Long-term aquatic toxicity data on Macrophyta from the OECD (2007) assessment (table 30, p 71)

Test substance	Test organism	Test duration	Effect	Endpoint [mg Fe/L]	Reference	Author’s Reliability
FeCl3	Spirodela polyrrhiza	14 d	Growth effects at pH 7.5	<0.56 (NOEC, m)	Sinha et al. 1994	R2
				0.56 (LOEC, m)

m = measured total iron

R2 = Rating by the authors (OECD 2007) referring to the Klimisch et al. (1997) scale, corrected to Klimisch 3 “not reliable” as discussed above.

Saltwater species:

No relevant data were reported by Vangheluwe & Versonnen (2004), Johnson et al. (2007) and OECD (2007).

• Johnson I, Sorokin N, Atkinson C, Rule K, Hope S-J (2007). Proposed EQS for Water Framework Directive Annex VIII substances: iron (total dissolved). ISBN: 978-1-84432-660-0. Science Report: SC040038/SR9. SNIFFER Report: WFD52(ix). Product Code SCHO0407BLWB-E-E. Self-published by Environment Agency, Almondsbury, Bristol BS32 4UD, U.K. 65 p.
• Klimisch H-J, Andreae M, Tillmann U (1997). A systematic approach for evaluating the quality of experimental toxicological and ecotoxicological data. Regul Toxicol Pharm 25:1-7.
• OECD Organisation for Economic Co-operation and Development (2007). SIDS Initial Assessment Report for SIAM 24. Chemical Category: Iron Salts. Self-published, Paris, France, 17-20 April. 138 p.
• Sinha S, Rai UN, Chandra P (1994). Accumulation and toxicity of iron and manganese in Spirodela polyrrhiza (L.) schieiden. Bulletin of Environmental Contamination and Toxicology. 53(4):610–7.
• Vangheluwe M, Versonnen B (2004). Critical review on acute and chronic aquatic ecotoxicity data to be used for classification purposes of iron sulfate. Commissioned by ARCELOR SA, CEFIC, EUROFER, Rio Tinto plc. Final report - 25 August 2004. Prepared by EURAS, Rijvisschestraat 118, box 3. B-9052 Gent, Belgium. 76 p.
• Wang W. 1986. Toxicity tests of aquatic pollutants by using common duckweed. DOI 10.1016/0143-148X(86)90028-5 Environmental Pollution Series B 11(1):1-14.