Sinapic acid is one of the most common hydroxycinnamic acids and is widespread in the plant kingdom. It has been identified in various fruits, vegetables, cereal grains, oilseed crops, some spices, and medicinal plants. Sinapic acid and its derivatives possess antimicrobial, antioxidant, anti-inflammatory, anticancer and anti-anxiety activities.

(E)-Isoeugenol is crystalline while compound with spice clove type odor. The melting point of E-isoeugenol is 33°C. E-Isoeugenol has been shown to cause contact and allergic dermatitis in humans. Positive skin patch tests in numerous individuals have confirmed the sensitizing ability of isoeugenol.

Quaternium-15, a preservative, is one of the most used substances and is added to several cosmetics and other industrial products. Quaternium-15 is a mixture of isomers, where the cis-form is the dominant form and where the trans-form is the minor component present as an impurity. Quaternium-15 can be found under a variety of names, most commonly those of the Dow Chemical Company: Dowicil 200 (cis isomer only), Dowicil 75 and Dowicil 100 (both a mix of cis and trans isomers). The isolated cis-compound is used primarily in cosmetic applications, with a maximum permitted concentration in the EU of 0.2%. DOWICIL 200 preservative (cis form) is used primarily as a preservative in a wide variety of personal-care and cosmetic products. It is designed to provide highly effective broad-spectrum antimicrobial activity, especially in water-based formulations. It is used in both leave-on and rinse-off application such as baby-care products, hair-care products, lotions, powders, and creams. The mixed product (cis- and trans-) is used in a wider range of formulations such as: emulsifiable metal-cutting fluids; latex and emulsion paints; liquid floor polishes and floor waxes; glues and adhesives. Recently, the cis-form has been classified as a CMR substance with the classification toxic to reproduction, category 3. This classification only concerns the cis-isomer: