Construction is seeing the introduction of remarkable new nano-enabled products that are lighter, stronger, more wear-resistant and better insulators. But some nanoparticles added to these products may cause health problems and very little worker exposure measurements have been collected, particularly in construction. That is why CPWR created this inventory. We believe, at a minimum, construction workers and contractors have a right to understand which products may contain nanoparticles so they can better consider the benefits and risks.