This color is of historical interest and some painters prize it for its qualities. This color is not always available. In general, genuine Mercuric Sulfide related colors are toxic. There is online debate about its true toxicity, and we recommend consulting a toxicologist if you are curious about that. As with other artists colors please refer to information from the manufacturer about the composition as well as the risks of handling these materials. It’s beyond the scope of the site to point out the toxicity of every artists’ paint, as we are artists and not health experts, however if one stands out to us we will mention it. The Paint List recommends seeking the opinions of third party health and safety specialists for information about hazardous materials contained in all of one’s artist paints. In terms of lightfastness there is also debate online and in artists’ circles. Despite vermillion’s charm, we found the lightfastness tests done by the legendary Gunzorro to be very helpful. His tests of genuine vermillion displayed darkening in bright sunlight over time: https://www.wetcanvas.com/forums/topic/vermilion-test/page/5/