Assessment of the dermal and ocular irritation potential of multi-walled carbon nanotubes by using in vitro and in vivo methods

In view of increase in the manufacture of various nanomaterials runs the risk of increased human exposure, in vitro screening will serve as a preliminary method to assess possible risk in animal studies. We attempted to know whether the validated in vitro alternative models established for chemicals, drugs, pesticides are suitable for nanomaterials, since these materials differ largely and may interfere with commonly used test systems. In vitro and in vivo studies on ocular and dermal irritation were carried out with two different sizes of multi-walled carbon nanotubes (MWCNT). The results of acute eye irritation toxicity studies with two different sizes of MWCNT in rabbits demonstrated reversible conjunctival redness and discharge and exhibited minimal concern while acute dermal irritation studies indicated that MWCNT of two sizes were non-irritant to the skin of rabbits. Both the sizes of MWCNT revealed non-irritant result in HE-CAM test. In vitro skin (EPISKIN) irritation studies revealed that two sizes of MWCNT are non-irritant to skin. In conclusion this work purports, the future of alternative research lies in the validation of the methodology for nanomaterials.