text: Ductile iron pipe in the developed world is normally manufactured exclusively from recycled material including scrap steel and recycled iron. The pipe can be recycled after use.
  In terms of environmental impact, several studies have compared ductile iron pipe's impact on the environment with that of other pipe materials. A study by Jeschar et al. in 1995 compared the energy use and carbon dioxide () emissions produced in manufacturing pipes of various materials including concrete, ductile iron, cast iron and PVC, based on pipes with nominal diameter of 100 mm to 500 mm. The energy consumed in manufacturing ductile iron pipe was 19.55 MJ per kg and volume of emissions released during manufacture was 1.430 kg  per kg, compared to 68.30 MJ per kg of energy and 4.860 kg  per kg emissions for PVC pipes, and 1.24 MJ per kg and 0.148 kg  per kg for concrete pipes of the same diameter.
  Another study the following year, by the Forschungsinstitut für Chemie und Umwelt, had similar findings. However, it also took the lifetime of pipes into account. This study found improved environmental performance for ductile iron pipe in terms of energy consumed and emissions produced during manufacture due to its longer life span. A more recent study, published August 2012, by Du et al., carried out a life cycle analysis on six types materials used for water and waste water pipes, including ductile iron, PVC, high-density polyethylene (HDPE) and concrete. They found that at diameters of ≤ 24 in, ductile iron pipe had the highest "global warming potential" based on emissions from manufacturing, transportation and installation. At larger diameters, ≥ 30 in, ductile iron pipe had a lower "global warming potential", while PVC had the highest.
  According to a 2008 study by Koo et al., ductile iron pipe had the lowest impact on natural resource depletion, compared to HDPE pipe and PVC pipe.
  In November 2012, ductile iron pipe manufactured in the United States received certification as a sustainable product from the Institute for Market Transformation to Sustainability.