Sodium hydrogensulphate

Endpoint summary

Additional information

Sodium hydrogensulfate:

Sodium hydrogensulfate readily dissociates in water with an acidic reaction, resulting in hydrogensulfate anions and sodium cations. The hydrogensulfate anion (pKa=1,99¹) partly dissociates further to sulfate anion and the hydrogen cation, which is responsible for the acidic reaction. Because of their inorganic nature, neither sodium, nor hydrogensulfate or sulfate ions are subject to any kind of biological degradation. Both sodium as well as sulfate ions occurr naturally. Sodium ions are present ubiquitously in the environment and essential to all forms of life, and is not discussed further for this reason. The sulfate ion also occurrs naturally, and can be considered to form part of the sulfur cycle, being readily utilised by bacteria, fungi and many aerobic and anaerobic prokaryotic species. A summary of the potential pathways involved in the cycle of sodium sulfate are given in the summary (Reference: OECD SIDS 2005) (The sulfur Cycle Microbiology Prescott Harley and Klein 1996; College of Biological sciences 1993).

Sodium sulfate:

Microbes play pivotal roles in the sulfur cycle, and sulfate provides microorganisms with the possibility of carrying out sulfate reduction to derive their energy. Sulfate is also used as an electron acceptor to form sulfide (H₂S). This is a process known as dissimilatory reduction and occurs anaerobically. Alternatively, the reduction of sulfate for use in amino acid syntheses for example can also occur and is known as assimilatory reduction forming organic sulfur. Other microorganisms may reduce to elemental sulfur even further. Sulfite is also a critical intermediate that can be reduced to sulfide as well as re-oxidised to sulfate, completing the cycle.