Acute toxicity and 28-day repeated dose studies of multi-walled carbon nanotubes

Abstract

In the light of the increased production and use of multi-walled carbon nanotube (MWCNT) in consumer products, there is a need for screening the potential toxicity of this nanomaterial. In the present study, the researchers have investigated the acute dermal and acute eye irritation in rabbits and acute oral irritation and 28-day repeated administration of MWCNT in rats. A single dose of 5000 mg/kg was used to test Albino Rabbits for acute dermal and eye irritation test. Similar dose was given to Sprague Dawley Rats for the acute oral and 28-day repeated dose test. Clinical signs/manifestations were closely observed for the first four (4) hours post sample administration and was continued for 1,2,3,7 and 14-day observation period. In acute toxicity study, no treatment-related death or toxic signs were observed with MWCNT. In the 28-day repeated dose study, no significant differences in hematology and clinical biochemistry were detected between control and MWCNT. However, histopathology results revealed mild periarteriolar lymphoid cell depletion in the spleen and mild tubular cell degeneration on the cortex and medulla of both kidneys of the rats while no remarkable lesions were seen on the other organs of both female and male rats.