A naturally occurring compound found in the oils of citrus fruits, particularly lemons and oranges, is known for its distinct, refreshing scent. This organic compound is classified as a terpene and has been extensively used in a variety of applications, from flavorings and fragrances to green cleaning products.
The chemistry of limonene, especially its interaction with oxygen, is an area of interest for scientists and industry professionals. When limonene is exposed to oxygen, a common reaction that can occur is oxidation. This process involves the addition of oxygen to the limonene molecule, leading to the formation of various oxidation products. One of the key products of this reaction is limonene peroxide.
The oxidation process of limonene is not only chemically interesting but also has practical implications.
Recognizing the importance of these chemical reactions, regulatory programs like the U.S. Environmental Protection Agency’s Safer Choice have set specific guidelines. According to these regulations, d-limonene, when used as a solvent in Safer Choice-certified products, is limited to concentrations resulting in no more than 20 millimoles per liter (mmol/L) of potential oxidation products. This translates to a maximum concentration of 1.36 percent d-limonene in the overall product formulation. Furthermore, to prevent the rapid formation of oxidation products, combining d-limonene with oxidizers like hydrogen peroxide (H2O2) is not recommended. Additionally, due to its potential harmful effects on aquatic life, d-limonene is advised against in products designed for direct release into the environment .
refer to 5.5.2 of https://www.epa.gov/sites/default/files/2013-12/documents/standard-for-safer-products.pdf