On September 1st 2006 a new EU ruling came in to force which banned the use of citronella in commercial fly sprays. However horse and pony owners who make their own spray need not worry as this legislation only applies to insecticides produced for sale. What is worrying is that this makes a mockery of the new ruling as home made sprays are likely to contain far higher concentrations of citronella than the shop bought versions.

This new regulation is part of the Biocidal Products Directive (1998), which contains a long list of substances which have been banned only because no one has bothered to prove they are harmless. While it is well known that some horses will occasionally have an allergic reaction to citronella, which is classed as a "natural chemical", this problem is no worse than with any other ingredient.

It has been reported that 90% of "natural" fly repellents in the UK currently contain citronella. Manufacturers of these products could apply to have citronella exempted from the directive by submitting evidence of its safety and efficacy, but this could be costly. Developing an alternative formula which does not use citronella may be the cheaper! Indeed many firms already sell products which contain a citronella-free formula so this extra cost cannot be justified. These alternative products usually containing synthetic chemicals and many manufacturers are already working on other products to fill the impending hole in their natural ranges.

Lavender and eucalyptus have also been banned in commercially produced products, as has tea tree oil, which, although on the EU "guilty" list, is currently under review and may be exempted.