(Wine-Searcher) - The European Commission has issued a list of pesticides that are "candidates for substitution" including copper, which is widely used in vineyards.

The E.U. has issued a list of 77 "candidates for substitution" (CFS), pesticides for which national authorities must assess whether more favorable alternatives exist, including non-chemical methods, according to an announcement by the European Commission.

La Vigne magazine reports that 26 of the 77 are used to protect grapevines.

For winegrowers, by far the most important substance on the CFS list is copper sulfate, which has been used in Bordeaux mixture for well over a century to protect grapevines against downy and powdery mildews. Its use is approved by organic wine regimes, which consider it as an acceptable organic alternative to systemic chemicals.

According to a fact sheet issued by the commission, the list is the result of a comprehensive review of the active pest-control substances currently on the market and extensive consultation, based on an independent study.

The aim of issuing the list is to encourage more-sustainable crop protection. The document makes the point that the list should not be misconstrued as a list of banned substances, and that these substances will remain on the market and are deemed safe, but could be substituted when a viable alternative is made available.

Use of substances on the list continues to be approved by the E.U. for seven years instead of the normal 10-year period. If no alternative is found, then each E.U. country may continue to allow its use but in a more restricted way.

Copper sulfate is included on the list due its toxicity for aquatic organisms. The time it takes to break down in freshwater and marine sediments is considered too long.

According to Britt and Per Karlsson, in their book on organic wine, a study in 2011 showed that French winegrowing districts had particularly high concentrations of copper in their soils, more than 50mg per kilo. Its use on vineyards has been increasingly restricted in the last 10 years since the E.U. first mooted a ban.