Red Phosphorus Uses

Phosphorus is the nonmetallic element with the symbol P, and the atomic number of 15. It is a member of the nitrogen family, and is most commonly found in inorganic phosphate rocks. Phosphorus is a highly reactive chemical element, it is usually not found in its elemental form. Within the living cells, phosphorus is an important component of DNA and RNA, and occurs as phospholipids, which form the cell membrane. Phosphorus is also a component of ATP or adenosine triphosphate, which is the major source of energy for the cellular reactions taking place within the living cells. Phosphorus can be found in several forms or allotropes, which can be defined as structurally different forms of an element. Out of the all the allotropes of phosphorus, the most common ones are white and red phosphorus. This type of phosphorus was discovered by an Austrian chemist, Anton von Schrotter in the year 1845.

What is Red Phosphorus?

It is one of the several allotropes of phosphorus, which is however, more commonly considered as an intermediate phase between the white and the violet phosphorus. It is made up of four tetrahedrally grouped phosphorus atoms. It is a hard crystalline solid that is obtained by heating white phosphorus to 250 ºC. It can also be obtained by simply exposing white phosphorus to sunlight. If it is heated over 550 ºC, then we can obtain violet phosphorus, which is known as a thermodynamically stable form of phosphorus.

As compared to white phosphorus, it is not so dangerous, as it is not poisonous and it does ignite spontaneously in air, if temperature is below 260 ºC. So, it is relatively stable and less reactive than white phosphorus. However, at some temperature ranges, it can change back to white phosphorus. Many times, frictional heating is also enough to change it to white phosphorus. When heated, it can emit toxic fumes, which mainly contains phosphorus oxides. It is insoluble in water and carbon disulphide.

Using Red Phosphorus

Being more stable and less reactive than white phosphorus, it has found several industrial and pharmaceutical uses. It is used in making the strike plate of matchbox, while the match head is made with sodium chlorate or potassium chlorate. The friction produced when the match head makes contact with the strike plate generates heat, which is turn, reacts with both red phosphorus and chlorate. As a result, the match head lights up, and it changes back to white phosphorus.

Next to matchboxes, it can be found in fertilizers. The fertilizers made with it are found to be suitable for promoting plant growth, root development, and flower and seed production. The plants fertilized with red phosphorus-based fertilizers become resistant to diseases and pest invasion. It can help plants to synthesize proteins more effectively, which in turn, can help to ensure better growth and development. Apart from fertilizers, it is also used in the manufacturing of pesticides.

In the pharmaceutical sector, it is used in the synthesis of methamphetamine, which is a drug that can stimulate the central nervous system. To produce methamphetamine, it is combined with elemental iodine, which results in the production of hydriodic acid (HI). The hydriodic acid is then used to convert ephedrine or pseudoephedrine to methamphetamine. Methamphetamine is basically a psychoactive drug that can alter mood, and improve alertness and the level of energy by increasing the level of dopamine, serotonin and norepinephrine in the brain. Today, methamphetamine is used in the treatment of obesity and attention deficit hyperactivity disorder (ADHD). Methamphetamine has a high potential for being abused or misused, for which many laws and regulations have been enforced regarding its production and use.

In addition to these, it is used in the manufacturing of many other products including, fireworks, smoke bombs, semiconductors, pyrotechnics, electroluminescent coatings and in certain flame retardants at low concentration. As a flame retardant, it can help to control the outbreak of large fires. To sum up, red phosphorus is one of the most important allotropes of phosphorus, having a variety of applications in the industrial sector.