pmethoxyphenol
p-Methoxyphenol, also known as 4-methoxyphenol or MEHQ, is an organic compound with the chemical formula C7H8O2. It is a white crystalline solid at room temperature. The compound is characterized by a phenol ring substituted with a methoxy group at the para position. It is soluble in water and many organic solvents. p-Methoxyphenol occurs naturally in certain plants and is also produced synthetically. Its primary industrial application is as a polymerization inhibitor, particularly for acrylic monomers like methyl methacrylate and vinyl acetate. It functions by scavenging free radicals that initiate polymerization, thus preventing premature and uncontrolled reactions during storage and transport. In some cosmetic formulations, it has been used as a skin lightening agent, though its use in this capacity has faced regulatory scrutiny in various regions due to potential adverse effects. p-Methoxyphenol can be synthesized through various chemical routes, including the methylation of hydroquinone. It is considered a moderately hazardous substance and appropriate safety precautions should be taken when handling it.