Chemical toxicants include *inorganic substances* such as lead, mercury, hydrofluoric acid, and chlorine gas, and *organic compounds* such as methyl alcohol, most medications, and poisons for living things.
Toxic Chemicals is one of three general categories of toxic substances (the other two being: Biological toxicants (such as bacteria) and Physical toxicants (such as coal dust).
Chemical toxicants include inorganic substances such as lead, mercury, hydrofluoric acid, and chlorine gas, and organic compounds such as methyl alcohol, most medications, and poisons from living things. Wiki-Toxicity, accessed 2-Jun-14. [emphasis mine]
Some toxic chemicals are naturally occurring in nature, such as Arsenic, but are dangerous in higher concentrations.
Radioactive chemicals are not poisonous because of their chemical nature, and are not to be included within this tag.
For further reading:
- "Toxicity," Wikipedia Article, http://en.wikipedia.org/wiki/Toxicity
- "Substances and Toxics Science Resources," EPA Article, http://www2.epa.gov/science-and-technology/substances-and-toxics-science-resources