The EFSA Plant Health Panel examined in detail documents provided by Poland and Lithuania and evaluated the quality, quantity, accuracy and relevance of data. The Panel concluded that the evaluated risk assessments did not provide sufficient evidence to formally classify the common, giant and perennial ragweed as harmful.

The Ambrosia genus contains over twenty six species. Ambrosia spp. came to Europe at the end of the 19^th century with grain and seed from North America. The ragweed species most widespread in the European Union is the common ragweed, A. artemisiifolia, which is prevalent in Hungary and occurs in large quantities in northern Italy, Switzerland, Austria, France and recently in the southern and eastern parts of Germany.

Common ragweed grows to be two meters high. It spreads quickly in abandoned and uncultivated areas, but it also invades farm land where it affects a variety of crops. For example in Hungary the weed has recently become number one on the top-list of dangerous weeds. In France A. artemisiifolia is of increasing concern to sunflower growers.

Ragweeds produce pollen which can cause allergic diseases, including hay fever and asthma. Their pollen can be carried by wind for many days and affect people hundreds of kilometres away.

The PLH Panel recommended that the pest risk assessments should be revised and updated. with a separate risk assessment for each of the three species. EFSA scientific advice has been forwarded to the European Commission and will inform future measures to tackle Ambrosia.