Why is low atom economy considered undesirable?

Low atom economy is considered undesirable because it indicates that a significant portion of the reactants used in a chemical reaction does not end up in the desired product, leading to the consumption of more resources than necessary. When the atom economy is low, it means that a large quantity of materials is wasted during the reaction process. This not only exhausts resources more rapidly but also results in increased waste production, which can be harmful to the environment and can complicate waste management processes.

In contrast, high atom economy signifies that most of the reactants are converted into useful products, making the process more efficient and environmentally friendly. This efficiency is important in promoting sustainability within chemical processes, allowing for better utilization of raw materials while minimizing waste. Therefore, low atom economy directly equates to inefficiency in resource use and is considered unfavorable in the context of green chemistry and sustainable practices.