Red powder is a term with multiple meanings. Here are two interpretations: Firstly, red powder is a widely used ammonia aniline dye, also known as 221 purple-red powder. It is primarily used for coloring paints, inks, lacquers, leather, rubber, plastics, latex products, construction materials, printing inks, educational supplies, and cosmetics. With a broad range of applications, red powder is an important pigment in many industries. Secondly, red powder can also refer to Rhodamine B, a bright peach red synthetic basic fluorescent dye, also known as Rose Red B or basic rose essence. Rhodamine B is mainly used in laboratory cell fluorescence stains, colorants, papermaking industry, manufacturing paints and pigments, and can also be used for dyeing fabrics and leather products. However, Rhodamine B has certain toxicity and genotoxicity, and international research institutions have listed it as a Class 3 carcinogen, meaning its carcinogenicity to humans is questionable.