The studies on nanotechnology are mostly oriented towards synthesis and applications and not widely studied for their antioxidant ability and toxicity. In this study, the carbon nanoparticles synthesized from Eichhornia crassipes were evaluated for their antioxidant ability using DPPH, metal chelating ability using FeCl2, Phosphomolybdenum reduction and cytotoxicity using A549 cell lines. The IC50 value recorded for DPPH scavenging was more than 500μL and 300μL and 600μL concentration of CNPs for Phosphomolybdenum reducing activity. The IC50 value for metal chelating activity was recorded nearly at 1000μL. The cell growth inhibition was recorded less than 50% against the cell line A549 even at the concentration of 1000μL. The study proves that the carbon nanoparticles synthesized from Eichhornia crassipes was less toxic and safer to use as a biocompatible material.