Behavior change is a central factor, necessary for shifting to more sustainable waste management but 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, is 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 will come at the expense of other environmental and sustainability goals.