Coal tar can be injurious to health. Coal tar is also used to manufacture paints, synthetic dyes (notably tartrazine/Yellow #5), and photographic materials. In the coal gas era, there were many companies in Britain whose business was to distill coal tar to separate the higher-value fractions, such as naphtha, creosote and pitch. A great many industrial chemicals were first isolated from coal tar during this time. These companies included: Side effects of coal tar products include skin irritation, sun sensitivity, allergic reactions, and skin discoloration. It is unclear if use during pregnancy is safe for the baby and use during breastfeeding is
Birch tar Kierikki in Finland. Ends of fletching of arrows were fastened with birch-tar and birch-tar-and-rawhide lashings were used to fix the blade of axes in the Mesolithic period. Russia leather is a water-resistant leather, oiled with birch oil after tanning. This leather was a major export good from 17th and 18th century Russia, as the availability of birch oil limited its geographical production. The oil impregnation also deterred insect attack and gave a distinctive and pleasant aroma that was seen as a mark of quality in leather. Birch tar is also one of the components of Vishnevsky liniment. Birch tar oil