Ch. 7: Phenol

An operating room in 1924 (right)

In the 1820s, hospitals were filthy. Many patients died from a preventable disease such as gangrene or the infamous "hospital disease". Because of these unsterile condition, Joesph Lister, an American doctor, began experimenting with carbolic acid, a waste product of coal gas, for use as an antiseptic. Lister first tested this method on a boy with a compound fracture. He applied the carbolic acid to the boy's wound and it formed a scab-like covering over the injury. The boy's wound never became infected and thus proved carbolic acid as an effective antiseptic. The active ingredient in the carbolic acid was Phenol. Through the years, carbolic acid usage became more widely used and more refined. Carbolic acid was use in surgery to prep and clean the surgical area and a machine was even made to spray a fine carbolic acid solution into the air to kill airborne bacteria in the operating room. But as many surgeons learned, the main ingredient in carbolic acid, Phenol, was highly toxic. Even in dilute solutions, it caused bleaching, cracking, and numbness of the skin and when inhaled, it caused severe illness. Because of this fact, many doctors refused to use phenol. (Le Couteur & Burreson 123-140)

Phenol is not only Lister's antiseptic molecule. The term, Phenol refers to any compound that has an OH
group attached directly to a benzene ring. There are literally hundreds of thousands of different phenols ranging from capsaicin, zigerone, and vanillin which are ingredients in flavorings, to Tetrahydrocannabinol (THC) which is the active ingredient in marijuana.(Le Couteur & Burreson 123-140)

Diagram of Phenols (above)
The most important use of phenol however, is its use in the discovery and manufacture of plastics. Leo Baekeland was able to use a formaldehyde and phenol compound to create the first plastic called Bakelite. The formaldehyde in the bakelite was able to react at 3 different places on the benzene ring of phenol, causing cross links among the polymer chains. The Rigidity in Bakelite is caused by these very short cross-links attached to the already rigid and planar bezene rings. Bakelite was a liquid that hardened rapidly into a transparent, amber colored solid that could completely conform to the shape of the mold into which it was poured. Once bakelite was formed, it was was frozen into its shape forever and would not melt. These characteristics made it ideal for electrical insulation.(Le Couteur & Burreson 123-140)
Phenol is responsible for the first use of antiseptic surgery, and created a new industry as well as thrusting the world into the Age of Plastic.