Registration Dossier

Ecotoxicological information

Sediment toxicity

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Key value for chemical safety assessment

Additional information

Experimental data on the toxicity of magnesium hydrogen orthophosphate (CAS 7757-86-0) to sediment organisms are not available. However, the chemical safety assessment does not indicate the need to investigate further the effects on sediment organisms. Based on the aquatic hazard assessment toxic effects of the substance on sediment organisms are not expected. Adverse effects of magnesium hydrogen orthophosphate were not observed for aquatic organism for all three trophic levels (fish, Daphnia, algae). Long-term toxicity of magnesium hydrogen orthophosphate is not anticipated due to the absence of acute toxicity and the fact that magnesium and phosphate are essential micronutrients for aquatic organisms. In addition, the substance is not expected to bioaccumulate.

Magnesium hydrogen orthophosphate is well soluble in water and the solubility of the substance is regulated by the pH under the environmental conditions. In release to aquatic environment the dissolved substance dissociates to magnesium cations and phosphate species. Both ions are generally abundant natural elements that are ubiquitous in the aqueous and terrestrial environment. Magnesium is among the most abundant elements in environment and is an essential nutrient for higher plants, algae and animals. It is the major component of chlorophyll and thus essential for plant photosynthesis. Magnesium plays a major role in metabolism, cellular function and is furthermore essential for the functioning of a great variety of enzymes.

Phosphorus is required by all living plants and animals. Phosphorus containing compounds are essential for photosynthesis in plants, for energy transformation and for the activity of some hormones in both plants and animals (Cornforth I.S., 2008). Since both ions are essential to most organisms, the uptake and concentration of magnesium and phosphate in organisms is controlled and regulated by a number of mechanisms. Thus, detrimental effects on sediment organisms are not expected due to the absence of acute aquatic toxicity, the low bioaccumulation potential and the fact that both ions are essential micronutrients.

References:

Cornforth I.S. (2008) The fate of phosphate fertilizers in soil. New Zealand Institute of Chemistry. II-Chemicals and Soils-D-Phosphate-2