Ever time we use the Coal Tar Topical solution at our compounding pharmacy it takes me back to when I was a kid. The smell is the same as telephone poles or walking alongside the railroad tracks. I thought I would do a little research on this product. This Coal Tar Solution is used to treat eczema, psoriasis, seborrheic dermatitis, and other skin disorders. What I was smelling at the railroad tracks was Coal Tar Creosote.
It was patented in 1838 by John Bethell for placing wood (railway ties, marine piling, lumber, posts, timbers, and utility poles) in a sealed chamber and applying a vacuum to remove air and moisture from the wood cells.
Next the wood is pressure treated with Creosote and then re-vacuumed to remove the excess treatment chemicals. The wood is then ready to be used and will not need to be replaced, in the field, for longs periods of use.
Creosote is a category of carbonaceous chemicals formed by the distillation of various tars and pyrolysis of plant-derived material, such as wood or fossil fuel. The smell largely depends on the naptha content in the creosote.
If there is a high amount, it will have a naptha-like smell, otherwise it will smell more of tar. Naptha is a flammable liquid hydrocarbon mixture, produced from natural gas condensates, petroleum distillates and the distillation of coal tar and peat.