Important Risk Analysis
Thursday, 21 January 2010 12:39

What is PRA or IRA?

Pest risk analysis is set of activities, in which the probability and the severity of impact of a particular pest is assessed, the means of reducing these are evaluated, and the results of this review are shared with those involved. It helps to ensure that decisions on the control of imports and exports are based on sound science, are related to the risks involved and have minimal impact on trade.


PRA the process

The elements of the PRA process are the identification of the pest(s), determining if the pest(s) meet the characteristics of a quarantine pest in accordance with the International Plant Protection Convention (IPPC) definition, assessing the level of risk and then selecting pest management procedures to deal with this risk. In the case of resource-poor countries, the range of pest management options available is limited, so the number and type of quarantine activities that become the import conditions, is limited.

The PRA process as described in the International Standards For Phytosanitary Measures No 2 (ISPM#2) is divided into three phases –

  1. Pest risk initiation

  2. Pest risk assessment

  3. Pest risk management

With the recognition that the principle of transparency is very important, most recent PRA reports have expanded Phase 3 to include a fourth phase Pest risk Communication/documentation.


The phases of the PRA process and difficulties with the process
Phase 1 Initiation

The initiation phase begins with the identification of the pest. In the PRA process for access of a commodity such as a fruit, a seed or a grain, the specific commodity has to be identified botanically and the parts of the plant that form this commodity have to be determined. Once this is completed, a list of pests in your country and also the country of export, can be prepared.

Difficulties are

  1. identification of the pests on a particular part of the plant

  2. stages of the lifecycle on a particular plant part

  3. correct classification of some pests due to changes in taxonomy

  4. identification of distribution of a pest to a particular country, or part of a country.

Phase 2 Pest Risk Assessment

To undertake this phase of the process a datasheet is compiled of all the technical information on the biology of the pest. The information for the datasheet is gleaned from as many sources as possible, and the country of export is obliged to provide it on request from the importing country. A standard datasheet format derived from the Australian Quarantine and Inspection Service (AQIS) PRA report is available.


Phase 3 Pest Risk Management

Once the list of quarantine pests is compiled from the long list of potential quarantine pests, those with similar characteristics (biologies) can sometimes be compiled into sub-groups that can be managed in the same manner, i.e. Surface pests can be visually inspected.

The facilities, equipment and the staff available will limit the management options for resource-poor countries. The classification of the pests into one of the three Pacific Plant Protection Organization (PPPO) categories (critical, non-critical and non-regulated pests) will determine where the treatment will take place. The type of treatment will depend on availability. In examining the type of treatment to be undertaken it is useful to consider actions that are possible at the various sequential stages of the production, packing and distribution process.

The management of pest risk can begin by simply listing a pest in your legislation as being a quarantine pest. It can move to more complex processes, some involving treatments. It is useful to look at pest management options as a time sequence from the point of selection of site and sowing, up to the point of sale. A number of options are listed in the slides of the IRA Workshop Manual.

The capacity to undertake these actions is limited by resources such as equipment, personnel, facilities and methodologies, such as sampling procedures. Treatments require chemicals and all the other resources listed above. Other management tasks are shown below in order of the commodity life cycle.


  • Variety grown – some are more resistant than others

  • Sow at a time to harvest before pests are economic – pest avoidance

  • Pest control methods – reduce pest level

  • Site in a pest free area – avoidance of pest – requires grower registration

  • Pest trapping using bait such as pheromones

  • Cultivation practices – bagging of fruit



  • Harvest when pests are not present, or when at low level – pest monitoring required

  • Select only healthy plants

  • Isolate harvested material to avoid re-infection


  • Accept only unblemished product

  • Remove any infected material

  • Clean commodity before packing – brushing, waxing etc


  • Identify individual producers on the packs – grower registration

  • Isolate packing area to avoid re-infestation

  • Isolate commodity after packing to avoid re-infestation- cool rooms


  • Treatments to be conducted in accordance with importers requirements

  • Dispatch or storage to avoid re-infestation

  • Certification of treatment on PC or inspection

Entry inspection

  • Inspection to level required to detect pest to required confidence limits

  • Audit of documentation

  • Feedback in case of non-compliance.

The complete process of production of a crop from ‘paddock to plate’ may not require any treatment with a chemical, but the same level of confidence in the quarantine risk is possible. This methodology is termed the ‘Systems Approach’.


The contents of this page came largely from the IRA Workshop Manual by Dr. Robert Ikin, Plant Protection Consultant.


Workshop Reports

IRA Papers