One disadvantage of green chemistry is that switching from an old product or process to a new one takes time. A redesign of the new process or product is often difficult, and there is lack of unity on what is deemed safer.
Another area of concern with green or sustainable chemistry is replacing the traditional pesticides or chemicals used in agriculture with biopesticides, which are pesticides derived from natural materials such as plants and animals. However, the process is slow, because on a large scale, the production costs are high.
Green chemistry promotes the design of chemical products and processes that reduce the production of hazardous substances.