Fumaric acid monoethyl ester is an almost white to beige crystalline powder used primarily for its preservative and polymerization properties in macromolecular materials. This compound is effective in inhibiting the growth of bacteria, yeast, and mold, thereby extending the storage life of products. Additionally, fumaric acid monoethyl ester plays a significant role in medical applications, particularly in the treatment of psoriasis, a chronic inflammatory skin condition. As the active ingredient in the antipsoriasis medication Fumaderm, it enhances keratinocyte differentiation and inhibits their proliferation, contributing to improved skin health.