Methyl cellosolve, also known as methoxyethyl ether or 2-methoxyethanol, is a chemical compound used as a solvent in various cosmetics and skincare products. It's a clear, colorless liquid with a slightly sweet odor mostly used to dissolve and disperse other ingredients in formulas. Methyl cellosolve should be handled with care because it can be toxic and may cause skin, eye or respiratory irritation if used improperly or in high concentrations.