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
English words of Greek origin "bacterium" < βακτήριον 'stick (diminutive)' is a kind of microorganism rather than a small stick or staff. This also applies to combining forms used in neologisms: "-cyte" or "cyto-" < κύτος 'container' means biological cells, not arbitrary containers; "-oma" < -ωμα, a generic morpheme forming deverbal nouns such as "diploma" 'a folded thing' and "glaucoma" 'greyness', comes to have the very narrow meaning of 'tumor' or 'swelling', on the model of words like "carcinoma" < καρκίνωμα. For example, "melanoma" does not come from Greek μελάνωμα 'blackness', but rather from the modern combining forms "melano-" 'dark (in biology)' + "-oma" 'tumor'.