There is not a single substance in existence that cannot kill you at high enough doses. There is a small amount of methanol in fruit juice. Cyanide in the pits and seeds of many fruits, red kidney beans contain lectin and must be cooked to reduce the concentration of that substance until they no longer cause sickness. Vitamin A in small doses is necessary for health but high doses can straight up kill you. Table salt (Sodium content) is also necessary but high doses can raise the risk of high blood pressure, heart attack and stroke. Fluoride strengthens enamel in small doses but causes a debilitating bone disease that results in bone deformities at high doses. "The dose makes the poison" is a common saying because it is true. I know people want to be able to categorize substances into toxins and not toxins but thats not how the real world works. The real world is complicated.