Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Acute toxicity to aquatic organisms was not experimentally determined for MgIDHA, but there are available data from studies on the source substances: chelating agent - IDHA and IDHA’s salts as well. 

Acute toxicity to fish

Acute toxicity to fish was experimentally determined for chelating agent IDHA and its salts: FeNaIDHA, Cu(2Na)IDHA, Mn(2Na)IDHA, Zn(2Na)IDHA. None of the substances showed a high toxicity.

The assessment of the acute toxic effects (mortality)  of IDHA chelating agent on a freshwater fish species (Brachydanio rerio) under static test conditions was conducted according to test method which is in most parts identical with OECD Guideline  203. No mortality or any abnormal swimming behaviour were observed. The LCO(acute fish toxicity)  of IDHA, sodium salt value for the fish is ≥ 100 mg/l (nominal) and ≥ 82.6 mg/I (calculated) (Bayer, 1997). All metal-IDHA complexes Fe(Na)IDHA, Zn(2Na)IDHA, Cu(2Na)IDHA and Mn(2Na)IDHA were investigated according to OECD 203 with Oncorhynchus mykiss, resulting in a nominal LC50(96h) value of > 100 mg/L (Nierzędska, 2007; Fochtman, 2009; Swierkot, 2011; Konfederak, 2013a). The LC50 (96h) values for MgCl2 for fish Pimephales promelas is 2826 mg/l, for Menidia beryllina is 13685 mg/l, for Cypridonon variegatusis 18084 mg/l and for Oncorhynchus mykiss (rainbow trout)is 13550 mg/l.

Acute toxicity to invertebrates

The EC100(48h) value > 100 mg/L is reported for Fe(Na)IDHA (Nierzędska, 2007), EC50(48h) > 100 mg/L is reported for Mn(2Na)IDHA (OECD 20, Konfederak, 2013b ), EC50(48h) > 38 mg/L is determined for Cu(2Na)IDHA (OECD 202, Konfederak, 2011) and EC50(48h) > 3.16 mg/L is determined for Zn(2Na)IDHA (Fochtman, 2009), a low to medium toxicity potential is predicted for aquatic invertebrates for IDHA metal-complexes.

Data summarized in PAN Pesticide Database (2018) report for magnesium chloride MgCl2indicate lack of toxicity against aquatic invertebrates.There are available acute toxicity data for five species zooplankton: LC50 of 2692.8 mg/L for Daphnia magna (5 studies), LC50 of 1075 mg/L forCeriodaphnia dubia (2 studies), LC50 of 6889.6 mg/L for Amerycamysis bahia (5 studies), LC50 of 720 mg/l for Harpacticoid copepod (1 study) andthe lowest LC50 was 32 mg/L forDaphnia hyalina(1 study). Also data for magnesium sulfate collected in PAN Pesticide Database indicated lack of acute toxicity. Average LC50 from 8 studies for Daphnia magnais 1978 mg/l.

Acute toxicity to algae

A low aquatic toxicity potential towards green algae was determined for iron, copper and manganese IDHA complexes. Cu(2Na)IDHA showed no toxicity potential towards fresh water algae and EC50(72h) > 250 mg/L. Similar result has been obtained with Mn(2Na)IDHA in Pseudokirchneriella subcapitata (ErC50(72h) = 598 mg/L and EyC50(72h) of 108.95 mg/L. For FeNaIDHA in OECD test no. 201 the values ExC50/72 h and EyC50/72 h above 72.3 mg/L were established based on measured concentrations. The worst results were for Zn(2Na)IDHA. The nominal value are: ErC50(72h) = 255.97 mg/L and EyC50(72h) of 8.01 mg/L, the measures values are: ErC50(72h) = 4.81 mg/L and EyC50(72h) of 0.86 mg/L.

There are no available study of acute toxicity with inorganic magnesium salts: MgCl2and MgSO4, but Hogan et al. (2013) conducted interesting study of toxicity of magnesium pulses to tropical freshwater species. The lowest IC50 values were obtained forH. viridissimaand they ranged from IC50(4h) 1351 mg Mg/l to IC50 630 mg Mg/l for continuous exposure.

Acute toxicity to microorganism

According to Column 2, section 9.1.4. of Annex VIII od REACH Regulation the study does not need to be conducted as the target substance Mg(2Na)IDHA is found to be readily biodegradable.

Additional information