The laws of thermodynamics deal with the irreversible flow of energy. Conservation of energy is the first law and increasing entropy (disorder) in an energy flow is the second. The conservation of mass is the equivalent first law for matter. It is commonly recognized. But what about the equivalent second law? For example, oil is a hydrocarbon liquid that is transformed to carbon dioxide, carbon monoxide and water vapor on combustion. That is an irreversible process that is contributing to climate change. Material in car tires is transformed into waste during operations. Many materials recycle naturally while some industrial materials are recycled. But, in my opinion, a second law of mass dynamics should take into account what happens to matter when it is transformed. Treating energy alone is misleading as energy is invariably a property of material and the energy being considered dependent on the operation being considered. The internal energy in water is the issue when electrolysis is used to transform water to oxygen and hydrogen. But it is the gravitational potential energy of water in a hydro pondage.