These tools are used to assess the environmental life cycle burdens of Nanoclay and Carbon Nanofibers synthesis. These nanoparticles have gained a lot of attention in recent years because of their applications in a wide array of industries. One of these applications is the manufacture of nanocomposites. Nanocomposites are a new class of composites that have a dispersed phase with atleast one ultrafine dimension, typically a few nanometers. The reinforcing phase in nanocomposites can be comprised of nanoclays, nanofibers, Single-Walled Carbon Nanotubes (SWCNT's) or Multi-Walled Carbon Nanotubes (MWCNT's). Polymer Nanocomposites can improve mechanical reinforcement, high temperature durability, enhanced barrier properties and reduced flammability. Although use of nanoparticles in various applications seems like a promising solution to achieve enhanced material properties, there are still several issues that need to be addressed for confirming their “benign nature”. It is critical to collect environmental, health data before encouraging the widespread use of products based on these nanoparticles as well as perform their Life Cycle Assessment to study the environmental impacts throughout a product's broader life cycle to ensure that the environmental impact is not just being shifted to other stages of the life cycle. In this paper, Nanoclay synthesis from Montmorillonites is considered as the first example. In the second example, catalytic pyrolysis of hydrocarbons on metallic catalyst to produce Carbon Nanofibers is studied. A “cradle-to-Gate” LCA was performed for these two kind of nanoparticles. The various steps in the life cycle along with the LCA results for the two types of nanoparticles will be described. In addition, steps in the life cycle with the maximum environmental burden will be described. Current work is in progress to integrate the fate and transport of these nanomaterials with the life cycle results to get an insight into the ecotoxicity of these nanomatertials. A thermodynamic LCA is also underway to get a preliminary insight into the ecotoxicity of these nanoparticles.