Dimethyl sulfate is a diester of methanol and sulfuric acid. Dimethyl sulfate is commonly used as a reagent for the methylation of phenols, amines, and thiols. Dimethyl sulfate is a potent genotoxic chemical. It can directly alkylate DNA both in vitro and in vivo. It have been shown to induce mutations, chromosomal aberrations, and other genetic alterations in a diversity of organisms. Dimethyl sulfate can cause severe burns to the skin, eyes, and respiratory tract. Systemic effects of dimethyl sulfate include damage to the liver and kidneys.

Guaiazulene is a blue compound. It is a derivative of azulene, guaiazulene is a bicyclic sesquiterpene that is a constituent of some essential oils, mainly oil of guaiac and chamomile oil. Guaiazulene is an U.S. FDA-approved cosmetic color additive. Guaiazulene is used in the formulation of bath products, cleansing products, depilatories, hair bleaches, hair conditioners, hair dyes and colors, hair straighteners, permanent waves, skin care products and skin fresheners. Guaiazulene has antioxidant, antifungal, antimicrobial, anti-inflammatory, anti-spasmodic, anti-ulcer, antitumoral activities and relaxant properties. Common side effects are: diarrhea, constipation, etc.