Plant defense against herbivory which differ from one another in both functional groups, and in basic carbon skeletons. Monoterpenoids, continuing 2 isoprene units, are volatile essential oils such as citronella, limonene, menthol, camphor, and pinene. Diterpenoids, 4 isoprene units, are widely distributed in latex and resins, and can be quite toxic. Diterpenes are responsible for making "Rhododendron" leaves poisonous. Plant steroids and sterols are also produced from terpenoid precursors, including vitamin D, glycosides (such as digitalis) and saponins (which lyse red blood cells of herbivores). Phenolics, sometimes called "phenols", consist of an aromatic 6-carbon ring bonded to a hydroxy group. Some phenols have antiseptic
Radioactive contamination from the Rocky Flats Plant of substantial contamination from the 1957 plutonium fire until after the highly visible 1969 fire, when civilian monitoring teams confronted government officials with measurements made outside the plant of radioactive contamination suspected to be from the 1969 fire, which consumed hundreds of pounds of plutonium (850 kg). The 1969 fire raised public awareness of potential hazards posed by the plant and led to years of increasing citizen protests and demands for plant closure. Releases from previous years had not been reported publicly prior to the fire; airborne-become-groundborne radioactive contamination extending well beyond the Rocky Flats plant was not publicly reported