Chapter 4: Toxic and Allergic Responses Caused by Secondary Metabolites Used in Cosmetic Formulations

Secondary metabolites are known as natural products that are used in cosmetics because of their beneficial properties, but the toxicity of some of them limits their use in personal care formulations. This chapter discusses, according to their classification, the plant secondary metabolites used in cosmetics that cause toxicity and allergic reactions in the human body. In addition, this chapter also discusses the secondary metabolites produced by microorganisms and animals that are used in cosmetic products. There are several secondary metabolites that are used in cosmetic preparations due to their beneficial properties, but when these metabolites are absorbed by the skin, they cause disruption to the skin following topical application. This chapter highlights the chemical compounds that are responsible for the toxic and allergic reactions.