Citronella oil is also a renowned plant-based insect repellent, and has been registered for this use in the United States since 1948. The EPA considers oil of citronella as a biopesticide with a non-toxic mode of action. Research also shows that citronella oil has strong antifungal properties, and is effective in calming barking dogs.
Both types probably originated from Mana Grass of Sri Lanka, which according to Finnemore (1962) occurs today in two wild forms--Cymbopogon nardus var. linnae (typicus) and C. nardus var. confertiflorus. Neither wild form is known to be used for distillation to any appreciable extent.
The market for natural citronella oil has been eroded by chemicals synthesised from turpentine derived from conifers. However, natural citronella oil and its derivatives are preferred by the perfume industry.
The US Environmental Protection Agency states that citronella oil has little or no toxicity when used as a topical insect repellent, with no reports of adverse effects of concern over a 60 year period. Because some products are applied to human skin, EPA requires proper precautionary labeling to help assure safe use. If used according to label instructions in the US, citronella is not expected to pose health risks to people, including children and other sensitive populations. The US Food & Drug Administration consider citronella oil as generally recognized as safe (GRAS).
Canadian regulatory concerns with citronella as an insect repellent are primarily based on data-gaps in toxicology, not on incidents. In Europe, Ceylon type citronella oil is placed on the category 3 list, with some safety concern regarding methyl eugenol.