Phosphorus is a chemical element with symbol P and atomic number 15. Phosphorus is essential for life (compounds containing the phosphate ion) are a component of DNA, RNA, ATP, and phospholipids. Elemental phosphorus exists in many allotropic forms, three major allotropes are white, red and black. Red phosphorus is a component of matchbook strike plates and is used as an ingredient in certain commercial rat and cockroach poisons. Red phosphorus is used in the manufacture of pyrotechnics, safety matches, semiconductors, fertilizers, pesticides, incendiary shells, smoke bombs, and tracer bullets. It is also used in organic synthesis reactions and in the manufacture of phosphoric acid, phosphine, phosphoric anhydride, phosphorus pentachloride, and phosphorus trichloride. Red phosphorus is also used in electroluminescent coatings and in flame retardants for polymers.

Direct reduced iron is an alternative iron source produced by heating an iron ore. In nature, most of the iron has an oxidized form.

Succinic acid is a dicarboxylic acid, which has multiple biological roles as a metabolic intermediate being converted into fumarate by the enzyme succinate dehydrogenase in complex 2 of the electron transport chain which is involved in making ATP, and as a signaling molecule reflecting the cellular metabolic state. Succinate is generated in mitochondria via the tricarboxylic acid cycle (TCA), an energy-yielding process shared by all organisms. Succinate can exit the mitochondrial matrix and function in the cytoplasm as well as the extracellular space, changing gene expression patterns, modulating epigenetic landscape or demonstrating hormone-like signaling. Dysregulation of succinate synthesis, and therefore ATP synthesis, happens in some genetic mitochondrial diseases, such as Leigh's disease, and Mela's disease and degradation can lead to pathological conditions, such as malignant transformation, inflammation and tissue injury. Succinic acid is a precursor to some polyesters and a component of some alkyd resins. Succinic acid also serves as the bases of certain biodegradable polymers, which are of interest in tissue engineering applications. As a food additive and dietary supplement, succinic acid is generally recognized as safe by the U.S. Food and Drug Administration. Succinic acid is used primarily as an acidity regulator in the food and beverage industry. It is also available as a flavoring agent, contributing a somewhat sour and astringent component to umami taste.[11] As an excipient in pharmaceutical products, it is also used to control acidity or as a counter ion. Drugs involving succinate include metoprolol succinate, sumatriptan succinate, Doxylamine succinate or solifenacin succinate.

Antimony (Sb) is a toxic metalloid that occurs widely at trace concentrations in soil, aquatic systems, and the atmosphere. Antimony is not an abundant element but is found in small quantities in over 100 mineral species. It is most often found as antimony(III) sulfide. Antimony is used in the electronics industry to make some semiconductor devices, such as infrared detectors and diodes. It is alloyed with lead or other metals to improve their hardness and strength. A lead-antimony alloy is used in batteries. Other uses of antimony alloys include type metal (in printing presses), bullets and cable sheathing. Antimony has been in medical use against microbes and parasites as well. Antimony-based drugs have been prescribed against leishmaniasis since the parasitic transmission of the tropical disease was understood in the beginning of the 20th century. As a therapeutic, antimony has been mostly used for the treatment of leishmaniasis and schistosomiasis. The major toxic side-effects of antimonials as a result of therapy are cardiotoxicity (~9% of patients) and pancreatitis, which is seen commonly in HIV and visceral leishmaniasis co-infections.

Aconitine is an alkaloid found in the Aconitum species. Aconitine is a highly toxic cardiotoxin and neurotoxin. In China and other countries, the herbal extract containing aconitine was used for the treatment of pain in musculoskeletal disorders, however the safety margin between therapeutic analgesic effect of aconitine and its known cardiotoxic effect is so narrow that the treatment may cause poisoning and death. The mechanism of aconitine action is explained by its ability to activate voltage-dependent sodium-ion channels.

Lead(II) acetate is a white crystalline chemical compound with a sweetish taste. Lead(II) acetate is used as a mordant in textile printing and dyeing, as a drier in paints and varnishes, and in preparing other lead compounds. It was historically used as a sweetener and for cosmetics.