Fluorine (F) is not considered an essential element for any organism, although its role in human biology has been debated. Currently, F is not classified as an essential element for humans, but it has a beneficial role in the maintenance and solidification of bones. Its primary role in humans is strengthening tooth enamel. F combines with saliva to protect tooth enamel from harmful plaque or sugars and prevent cavities. Sources of F for humans include tea, seafood, toothpaste, and water supply, if fluoridated (Aoun et al., 2018). Studies exploring F’s role in osteoporosis have been inconclusive, but it is generally thought that F does not have a significant role in preventing osteoporosis and fractures (Haguenauer et al., 2000). 

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F is not required for plants and can cause toxicity at high concentrations (Zuo et al., 2018). F is also not an essential element for microbes. However, some bacteria, such as Streptomyces cattleya, have been found to produce fluorinated secondary metabolites (Reid et al., 1995).