Diiron tris(sulphate)

Toxicity to aquatic algae and cyanobacteria

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: Acute aquatic toxicity data according to Johnson et al. (2007, table 2.7, p 24)

Scientific name	Common name	Endpoint	Effect	Test duration [d]	Concentration [mg/L] #	Exposure	Toxicant analysis	Comments (Author's Reliability)	Reference
Anabaena circinalis	Blue green alga	EC50	Growth	24	15	s	n	– (R3)	Chow et al. 1998
Microcystis aeruginosa	Blue green alga	EC50	Growth	24	15	s	n	– (R3)	Chow et al. 1998

# Concentration related to iron if not stated otherwise under comments (third-to-last column)

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

Exposure: s = static

Toxicant analysis: n = not measured.

Table: Acute aquatic toxicity data from the OECD (2007) assessment (table 28, p 65)

Test substance	Test organism	Test duration	Effect	EC50 [mg Fe/L]	Reference	Author’s Reliability
FeSO4.7H2O	Pseudokirchnerella subcapitata	72 h	Growth rate at pH 4.4 to 10.5	10 (measured)	MOE 2002	R1

R1 = Rating by the authors (OECD 2007) referring to the Klimisch et al. (1997) scale, corrected to Klimisch 3 “not reliable” as discussed above.

Table: Long-term toxicity 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	Reference	Reliability
FeSO4, FeCl3 Fe(NO3)3	Chlorella vulgaris	Modified liquid Beijerick’s medium		N	30 days	Physiological and morphological parameters	Becker & Keller 1973	R3

N: Nominal concentration

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

T: Temperature [°C]

Table: Long-term toxicity data 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
Anabaena doliolum	Blue-green alga	LOEC	Chlorohyll content	15	10	static	not measured	As FeCl3 (R3)	Rai & Mallick 1992
Anabaena doliolum	Blue-green alga	NOEC	Growth	10	50	static	not measured	– (R3)	Pany & Mitra 1998
Aulosira fertilissima	Blue-green alga	NOEC	Growth	10	50	static	not measured	– (R3)	Pany & Mitra 1998
Nostoc punctiforme	Blue-green alga	NOEC	Growth	10	50	static	not measured	– (R3)	Pany & Mitra 1998
Chlorella vulgaris	Green alga	LOEC	Chlorophyll content	15	5	static	not measured	As FeCl3 (R3)	Rai & Mallick (1992
Chlorella vulgaris	Green alga	NOEC	Growth	28	350	static	not measured	As FeCl3 (R3)	Becker & Keller 1973
Chlorella vulgaris	Green alga	NOEC	Growth – stimulation	28	350	static	not measured	As FeCl3 (R3)	Becker & Keller 1973
Chlorella vulgaris	Green alga	NOEC	Growth – stimulation	28	350	static	not measured	As Fe(NO3)3 (R3)	Becker & Keller 1973
Hydrodictyon reticulatum	Water net	LOEC	Growth	7	32	static	not measured	As FeCl3; pH 7.5 (R3)	Rai & Chandra 1992

# Concentration related to iron if not stated otherwise under comments (third-to-last column)

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

Test substance	Test organism	Test duration	Endpoints	NOEC [mg Fe/L]	Reference
FeSO4.7H2O	Pseudokirchnerella subcapitata	72 h	Growth rate at pH 4.4 to 10.5	10.2	MOE 2002

Saltwater species:

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

Table: Long-term aquatic toxicity data according to Johnson et al. (2007, table 2.8, p 28)

Scientific name	Common name	Endpoint	Effect	Test duration [days]	Concentration [mg /L] #	Exposure	Toxicant analysis	Comments (Author's Reliability)	Reference
Haslea ostrearia	Marine Alga	NOEC	Growth	10	1.9	static	not measured	As FeCl3	Moreau et al. 1994

# Concentration related to iron if not stated otherwise under comments (third-to-last column)

• Becker AJ, Keller EC (1973). The effects of iron and sulfate compounds on the growth of Chlorella. Proceedings of the West Virginia Academy of Sciences. 45:127–35.
• ECHA European Chemicals Agency (2012). Guidance on the Application of the CLP Criteria. Version 2.0, April 2012. Self-published by ECHA Reference: ECHA-12-G-06-EN, Date: 04/2012. 593 p.
• 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.
• MOE Ministry of the Environment, Japan (2002). Growth inhibition test of Pseudokirchnerella subcapitata for Sulfuric acid, iron(2+)salt(1:1), heptahydrate. Japan Food Research Laboratories, Tama, Japan. Report Number 13031. Report date 2002-03-29.
• Moreau C, Robert J-M, Rouillard I (1994). Effect of iron on the growth of the diatom Haslea ostrearia in batch culture. Cahiers de Biologie Marine. 35:269–79.
• NIER National Institute of Environmental Research, Korea (2001). Algae growth inhibition test of Iron(II) Chloride. Safety Research Center of Korea Research Institute of Chemical Technology, 100 Jang-dong, Yuseong-gu, Daejeon, Korea. Report Number EG01003.
• 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.
• Rai UN, Chandra P (1992). Accumulation of copper, lead and iron by field populations of Hydrodictyon reticulatum (Linn.) Lagerheim. Science of the Total Environment. 116(3):203–11.
• Rai LC, Mallick N (1992). Removal and assessment of toxicity of Cu and Fe to Anabaena doliolum and Chlorella vulgaris using free and immobilised cells. World Journal of Microbiology and Biotechnology 8:110–4.
• Vangheluwe & Versonnen (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.