Malachite green is an organic compound that is used as a dye stuff and controversially as an antimicrobial in aquaculture. Malachite green is traditionally used as a dye for materials such as silk, leather, and paper. Despite its name the dye is not prepared from the mineral malachite, and the name just comes from the similarity of color. Numerous niche applications exploit the intense color of Malachite green. It is used as a biological stain for microscopic analysis of cell biology and tissue samples. In 1992, Canadian authorities determined that eating fish contaminated with malachite green posed a significant health risk. Malachite green was classified a Class II Health Hazard.