Graphite, acid-treated

Toxicity to terrestrial arthropods

Description of key information

Graphite, acid-treated is an inorganic solid, consisting of natural graphite and variable amounts of either intercalated nitric acid or acetic acid. The main component – graphite - is a naturally occurring inorganic solid substance which is insoluble in water. Due to its physico-chemical properties, i.e. absence of lipophilic functional groups which would enhance lipid (fat) solubilisation properties and therefore facilitate the uptake into the organism, graphite itself can be regarded as not bioaccumulative and harmless. Graphite itself cannot degrade and cannot adsorb to organic matter in soil or sediment. 
The intercalated nitric acid or acetic acid and the intercalated ions (nitrite/nitrate, acetate) are partially leached out by water. Once the intercalated acid and/or ions are leached out by water into the environment or are taken up in the organism, they are subject to ready biodegradability. Therefore, accumulation in the cells or tissues of organisms can be excluded. Due to the strongly polar character of the ions the assessment of adsorptive/desorptive behaviour to organic soil matter can be regarded as negligible.
Due to its inherent properties (not bioavailable, not degradable, no absorption to soil or sediment), graphite, acid-treated does not pose a toxicological risk for soil-dwelling organisms. The absence of bioavailability of graphite, acid-treated in soil has been demonstrated by a study on acute toxicity (14 days) to earthworms. In this study, the NOEC for graphite, acid-treated was determined to be 1,000 mg/kg sdw, confirming that graphite, acid-treated does not pose toxicological risks for the soil compartment. 
Relevant exposure of soil to graphite, acid-treated is unlikely regarding its use pattern. Against this background testing is not required under Regulation (EC) No 1907/2006 (REACH).