there is a lack of research with regards to behavior change intervention. Critics of Zero Waste point out that a material could be reusable, organic, non-toxic, and renewable but still be ethically inferior to single use products. Bags made of baby seal pelts or tiger skin, for example, theoretically meet the definitions of "zero waste", but are hardly superior to single use plastic bags. Similarly, a toxic material, such as lead in solder, may be replaced by less toxic materials like tin and silver. But if the mining of silver and tin releases more mercury or damages sensitive coral islands, the protection of landfills in developed nations is hardly paramount. While zero waste advocates have sophisticated answers as to why these examples do not meet the definition of Zero Waste (e.g., that the bodies of seals and tigers, or mining waste, are of equal concern), critics say that Life Cycle Analysis, habitat protection, carbon neutralization, or "Zero Extinction" are more environmentally astute philosophies than waste-centric measures. The simple accounting of measurable waste diversion, reuse, recycling rates, etc. is an attractive and useful tool, but a campaign based on a goal of literally stopping the last 5% of waste might come at the expense of other environmental and sustainability goals. Within the waste industry itself, other tensions exist between those who view zero waste as post-discard total recycling of materials only and those who view zero waste as the reuse of all high-level functions. It is probably the defining difference between established recyclers and emerging zero-wasters. A signature example is a difference between smashing a glass bottle (recovering cheap glass) and refilling the bottle (recovering the entire function of the container). The tension between the literal application of natural processes and the creation of industry-specific more efficient reuse modalities is another tension. Many observers look to nature as an ultimate model for production and innovative materials. Others point out that industrial products are inherently non-natural (such as chemicals and plastics that are mono-molecular) and benefit greatly from industrial methods of reuse, while natural methods requiring degradation and reconstitution are wasteful in that context.. Whether made of starch or petroleum, the manufacturing process expends all the same materials and energy costs. Factories are built, raw materials are procured, investments are made, machinery is built and used, and humans labor and make use of all normal human inputs for education, housing, food etc.