Sulphuric acid, compound with graphite

Long-term toxicity to fish

Description of key information

According to ECHA Guidance on information requirements and chemical safety assessment, studies on aquatic toxicity do not need to be conducted if there are mitigating factors indicating that aquatic toxicity is unlikely to occur (e.g. the substance is highly insoluble in water or the substance is unlikely to cross biological membranes). 
Sulphuric acid, compound with graphite is an inorganic solid, consisting of natural graphite and variable amounts of intercalated sulphuric acid. 
Graphite is a naturally occurring solid substance which is insoluble in water. Due to its physico-chemical properties it is not systemically and biologically available and does not cross biological membranes. In the aquatic compartment it can be considered as an inert substance.
 The intercalated sulphuric acid is partially leached out by water and dissociated into the environmentally ubiquitous sulphate and hydronium ions. Due to their ionic character, they do not cross biological membranes. Sulphate is a normal biological constituent of the body, a normal biological metabolite and a degradation product of sulphur-containing amino-acids. In the aquatic compartment the sulphate ions are precipitated in form of naturally occurring minerals. 
The results of the studies on acute toxicity to fish (see section 6.1.1 of the IUCLID dossier) and on acute toxicity to daphnids (sees section 6.1.3 of the IUCLID dossier) underline that sulphuric acid compound with graphite is not systemically available. In both studies the NOEL for sulphuric acid, compound with graphite was determined to be > 100 mg/L, confirming that sulphuric acid, compound with graphite does not pose acute toxicological risks for aquatic organisms. 
Against this background, it can be concluded that long-term toxicity to fish is not a concern for sulphuric acid compound with graphite and performance of a study is considered not to be necessary.