Lesson 1: Review of PRA and Introduction to Risk Assessment

Topic 3: The International Framework for PRA and Pest Risk Assessment

In this topic, we will discuss the international framework for conducting PRA and the basic process used for conducting phytosanitary risk analyses. We will examine what pest risk assessment is and why it is done.

Objectives:

  • Be able to define the terms pest risk analysis and pest risk assessment
  • Be able to identify the basic steps in the PRA process as outlined by the IPPC
  • Be able to identify who conducts pest risk assessments and how they are done

In the last topic, we discussed how risk assessment involves the evaluation of the likelihood that an adverse event will occur and the magnitude of the associated consequences. In the plant health world, the adverse event we are usually concerned about is the introduction and spread of quarantine pests. (Recall from earlier modules that the term introduction refers to both the entry of a pest and its establishment.) Note in the language of the IPPC that a pest is “any species, strain or biotype of plant, animal or pathogenic agent injurious to plants or plant products.” Previous modules have gone into a great deal of detail defining what a quarantine pest is; therefore, we will not do that here. But if you are not comfortable with that term, you should review those modules.

As mentioned in previous modules, the International Plant Protection Convention (IPPC) is the official standard-setting body for plant health issues for all members of the WTO. There are currently two IPPC standards relevant for assessing the risk to plant health posed by quarantine pests:

  • ISPM 2: Framework for pest risk analysis (2007)
  • ISPM 11: Pest risk analysis for quarantine pests (2013)

According to these standards, all PRAs consist of three basic stages:

  • Stage 1: Initiation
  • Stage 2: Pest risk assessment
    • Pest categorization (identifying potential pest “hazards”)
    • Estimation of likelihood of introduction (or likelihood of occurrence) and spread
    • Assessment of economic consequences (or magnitude of consequences)
  • Stage 3: Pest risk management

Under this model, risk communication is not considered to be a discrete stage, but instead, it is described as a process that should be conducted throughout all stages of the PRA. The diagram below summarizes what occurs at each stage. Regulatory decisions cannot be made until all three stages have been completed. It is included in the diagram below to help you understand where decision-making fits within the larger PRA framework.

PRA Process
Initiation
  • Describe the concern that has created the need for a PRA
  • Identify the pests of concern and the best information sources
  • Identify the size of the PRA area to be evaluated

Pest Risk Assessment
  • Categorize the identified pests
  • Assess the potential of pests’ entry and spread
  • Assess the potential for economic consequences

Pest Risk Management
  • Identify risk management options that reduce the phytosanitary risk to an acceptable level and are cost effective and feasible

Regulatory Decisions
  • Evaluate risk management options against scientific evidence, current regulatory policies and practices, and the political, social, and economic environment to apply phytosanitary measures, if appropriate

See ISPM 2 and ISPM 11 for more detailed information about the steps discussed in this module.

What is Pest Risk Assessment?

The IPPC defines pest risk assessment (for quarantine pests) as “evaluation of the probability of the introduction and spread of a pest and the magnitude of the associated potential economic consequences.” [FAO, 1995; revised ISPM 11:2001; ISPM 2:2007]. This process generally begins by identifying the quarantine pests—or hazards—that pose a risk in the situation we are analyzing.

Why is Pest Risk Assessment Done?

There are many reasons that countries conduct pest risk assessment, not all of which are trade related. Basically, risk assessment should be conducted whenever guidance about the level of risk is needed to in order to make a decision.

Risks related to trade
Risks related to trade
  • Determine the risk of pests associated with the import or export of organisms or agricultural products that may be contaminated with plant pests
  • Identify pests of concern not yet present in our country, and identify the potential pathways those pests might be introduced

Risks related to domestic issues
Risks related to domestic issues
  • Evaluate whether a particular control program for a particular pest should be implemented, terminated, or whether it should change directions
  • Evaluate different control strategies
  • Determine whether a particular pest should be regulated

Risk related to policy decisions
Risk related to policy decisions
  • Determine if regulations should be changed
  • Determine whether recommendations for mitigating or controlling a particular pest should be changed
  • Identify emerging issues of concern

Resource allocations
Resource allocations
  • Determine how resources should be allocated across several programs or agencies
  • Prioritize pests and identify greatest pests of concern

Note that even though nontrade-related PRAs do not have to conform to SPS-IPPC obligations, we can and should use the same approaches and methodologies.

Pest risk assessments are conducted in many different ways, including:

  • Creating a new document from scratch
  • Modifying an existing assessment
  • Extracting from a standard
  • Developing jointly with your trading partner or harmonized with another country
  • Through multiagency or intragovernmental cooperation
  • With the cooperation of industry
PRA Initiation Points

As mentioned in Module 3.5, a pest risk analysis may be initiated for many reasons. Some examples include:

  • Identification of a new pest of concern
  • New pathway of introduction, such as a request from a trading partner for market access for an agricultural commodity
  • Policy review or revision
  • Need to provide justification for a regulatory decision
  • Operational evaluation
  • Trade dispute

In the next lessons, we will discuss the PRA stages of initiation and pest risk assessment in much greater detail. We will also discuss the resources needed for conducting pest risk assessment. But first, let’s discuss some of the different approaches countries may take for conducting pest risk assessment.

To continue, select Topic 4 from the Topics menu above or click here.