EPPO Global Database

EPPO Reporting Service no. 12 - 2003 Num. article: 2003/176

EPPO Concept of A1 and A2 Lists and the Principle of Solidarity

EPPO NOTE (2021-02): The article below was published in 2003, but when preparing the revision of the introductive text of the EPPO A1 and A2 Lists, the EPPO Secretariat noted that this article no longer reflects the current approach of EPPO for pest listing. Principles for establishing and maintaining the EPPO A1 and A2 Lists are currently described in the section requirements of PM 1/002 EPPO A1 and A2 Lists of pests recommended for regulation as quarantine pests (see https://gd.eppo.int/standards/PM1/).

Original text of the article published in 2003:

The EPPO concept of A1 and A2 lists and the associated principle of solidarity were discussed by the Panel and Working Party on phytosanitary regulations at several occasions, but results of the discussions were never published as such. As discussions about these concepts are continuing among the EPPO member countries, it was felt useful to publish them in the EPPO Reporting Service.

EPPO Concept of A1 and A2 Lists and Principle of Solidarity
According to a certain conception of the SPS Agreement, countries are only technically justified in protecting plant life and health on their own territories. Thus, quarantine pests only concern individual countries: A1 pests for an individual country are those that are absent (though they might be present in that country’s immediate neighbours), while A2 pests are those which are present but not widely distributed and subject to official control. In this conception, RPPOs have no basis to draw up A1 and A2 lists, but only to advise countries of a single list of recommended quarantine pests for their members, which will be A1 or A2 for each individual country according to its pest status.

However, EPPO continues to recommend regional A1 and A2 lists. These are justified by considerations that go beyond those of the above paragraph:

  1. A1 pests are ‘exotic’ to the region. Their potential in EPPO countries is relatively uncertain, since there is absolutely no experience of it, so the measures recommended to EPPO members are relatively strong. EPPO thus implies that the appropriate level of protection for such exotic pests should be high. On the other hand, A2 pests are known in the region, and there is shared experience of what they can do. There is also experience of measures taken against them. The measures which EPPO recommends for A2 pests should thus be in line with the principle of ‘managed risk’, and it is easier to determine what are the measures that are not more stringent than necessary. In practice, this means that these measures are generally less stringent than those for A1 pests. Because EPPO knows the risks from A2 pests better than those for A1 pests, it can better establish what is an acceptable risk.
  2. The A1 list is also underlain by a principle of regional solidarity.

EPPO members cooperate in preventing the introduction of A1 quarantine pests into any part of the EPPO region by regulating all A1 pests as quarantine pests in their national legislation. Since the pests concerned present greater risks to some Members than others, the countries facing the lesser risks act ‘in solidarity’ by taking the EPPO recommended measures. The EPPO Working Party on Phytosanitary Regulations maintains the view that such measures are justified in appropriate cases, but notes that the appropriate circumstances have to be established.

The Panel on Phytosanitary Regulations examined various scenarios and concluded that taking measures against a ‘lesser risk’ is adequately covered by existing principles in many cases. In particular, taking the EPPO A1 list as an example, if the entry or establishment of an A1 pest into one EPPO country presents a low direct risk to that country, but could affect its trade to other EPPO countries where the pest would be more important, then appropriate measures are justified. The restrictions on trade may not yet exist as such, but it may be supposed that they would be imposed.

In a second scenario, there is no obvious risk to trade, but establishment of an A1 pest in the first country presents a risk of natural spread to the second. This is where an explicit solidarity principle is needed and the Panel proposes that: ‘Phytosanitary considerations may include the prevention of introduction of quarantine pests into other countries with which cooperation has been established, provided that PRA methods based on biological and economic evidence have been used to demonstrate the risk of such introduction’.

A third scenario is represented by the wording ‘Phytosanitary considerations may include the prevention of introduction of quarantine pests into any of a group of countries which have agreed to form a single market, with no or limited phytosanitary measures between its members’.

In the fourth scenario, there is little or no risk to the importing country, no possible effect on trade, and no risk of natural spread to a country where there is a risk. Phytosanitary measures would not be justified.


EPPO Secretariat (2003-12).