Biologically synthesized organofluorines are few in number, although some are widely produced. The most common example is fluoroacetate, with an active poison molecule identical to commercial "1080". It is used as a defense against herbivores by at least 40 green plants in Australia, Brazil, and Africa; other biologically synthesized organofluorines include ω-fluoro fatty acids, fluoroacetone, and 2-fluorocitrate. In bacteria, the enzyme adenosyl-fluoride synthase, which makes the carbon–fluorine bond, has been isolated. The discovery was touted as possibly leading to biological routes for organofluorine synthesis.
Fluoride is considered a semi-essential element for humans: not necessary to sustain life, but contributing (within narrow limits of daily intake) to dental health and bone strength. Daily requirements for fluorine in humans vary with age and sex, ranging from 0.01 mg in infants below 6 months to 4 mg in adult males, with an upper tolerable limit of 0.7 mg in infants to 10 mg in adult males and females. Small amounts of fluoride may be beneficial for bone strength, but this is an issue only in the formulation of artificial diets. (See also fluoride deficiency.)