Measure category: reduce pests in the consignment

Risk reduction objective: reduce infestation rates

Measures in this category include:

  • Treatment to kill or inactivate the pest
  • Physical disturbance or processing
  • Surface cleaning
  • Remove contaminants

Note that this resource is a working draft, which is currently being reviewed and updated in collaboration with biosecurity specialists.

Overview of measure category

Infestation rates are reduced by killing, inactivating or removing the pest from the commodity. Removal can be achieved by physical removal or removing parts of the commodity or contaminants that are most at risk of infestation. Measures can include treatments or processes specifically applied to reduce infestation rates, or commercial processes for which reducing infestation rates is an unintended benefit.

Required proof of efficacy

Efficacy of the treatment or process is typically determined experimentally. It needs to consider mortality, removal or inactivation rates of relevant life stages, and commercially relevant physical conditions relevant such as core temperature of the produce in storage.

How these measures are certified

Audit of treatment records and processes. In some cases, testing can be conducted to ensure treatments have been applied (e.g. of chemicals) or the commodity can be inspected to ensure treatment was efficacious.

How these measures are used

A diverse and commonly used category of measures. Existing commercial practices can be considered in the PRA. Many of the measures can be used either as a “single point” treatment or as part of a phytosanitary systems approach.

Relationship with other measures

Often combined with other measures (e.g. to minimise exposure to pests during production), even when applied as a “single point treatment”. This may be due to lack of data supporting the single-point treatment or concerns regarding treatment application. When combined with other measures there is potential for them to be used with a lower mortality threshold. For example, partial mortality or pest removal treatments can be combined with others measures that reduce initial infestation risks.

Consignment stages where the measures can be applied

Treatment (to kill or inactivate the pest)YesYesYes
Physical disturbance and processingNoYesYes
Surface cleanNoYesNo
Remove contaminantsNoYesNo

Measures in detail: reduce pest in consignment

MeasureRequired proof of efficacyHow the measure is certifiedHow the measure is usedRelationship to other measures
Treatment (to kill or inactivate pests)
Physical or chemical treatments applied to kill or inactivate pests in or on the commodity. May include heat, cold, drying, irradiation, agrochemicals, high pressure, cold + MA; combination kill treatment; Other
There are well established methods to quantify mortality effects of most treatments. Efficacy needs to be estimated for the least susceptible life stages, and under relevant environmental conditions, and is often summarised as the treatment required to achieve probit 9 (99.9968%) or probit 8.7 (99.9%) mortality.  Time-dependent mortality functions can also be important to estimate.Audit of treatment records and processes. In some cases, testing can be conducted to ensure the treatment has been correctly applied or inspection made of commodity to ensure treatment was efficacious.  Certified treatment or environmental loggers are often required.Treatments include agrochemicals such as through fumigation, spraying and dipping, heat, cold, drying, irradiation, high atmospheric pressure, and cold combined with modified atmosphere. Treatment selection is influenced by efficacy, cost, practicality, any negative quality impacts and food safety implications. Commonly applied post-production or post-border as a single-point measure (“end point treatment”), but can also be a commercial process (e.g. prolonged cold storage). Can be applied during production, e.g. the use of systemic pesticides on fruit.Measures to minimise fruit infestation rate prior to treatment are often required, even where treatment efficacy is high. Even the presence of dead or inactivated (in the case of irradiation) pests may be sufficient grounds for consignment rejection. Partial kill treatments may be sufficient depending on the PRA or incorporation of measures that limit infestation rate prior to treatment. Agrochemicals applied during production can have a dual effect of managing pest populations and reducing pre-harvest infestation rates in produce. Often this distinction is not well articulated or quantified.
Physical disturbance and processing
Infestation rate in the commodity reduced through the application of physical disturbance or processing
Experimental work is generally needed to demonstrate stage-specific mortality or removal resulting from physical disturbance or processing. Results need to be confirmed under commercial settings, which can be challenging where the application of disturbance is not standard across the industry.Audit of treatment records and processes. Effects of measures may also be auditable.Relevant processing activities depends on the commodity but can include milling, juicing and cooking. Physical disturbance can include turning of the bulk storage (e.g. grains), sometimes as a specific pest management measure. Can be applied post-production and post-border.  Distinguished from the “treatment” measure as most often occurs as part of the production system. Where efficacy of physical disturbance and processing is insufficient it can be combined with other measures that give confidence that initial infestation rates are low.
Surface cleaning
Pests are removed from the surface, and/or the surface is sterilised, using one or more physical or chemical methods.
Can be quantified experimentally using infested commodities and confirmed under a commercial setting. Studies need to account for the biology of the pest, the least sensitive life stages, and the diversity of commercial, post-production practices.Audit of treatment records and processes. Effects of measures may also be auditableSurface cleaning is only possible for certain surface pests and for where treatments don’t affect the quality of the commodity, can be audited, and are sufficiently standardised across processing facilities. Many methods are possible include brushing, washing with water or detergent, and the use of surface sterilisers. These can be considered during the PRA where they are standard production practices or included as phytosanitary measures.Distinguished from the “treatment” measure as most often occurs as part of the production system. Surface cleaning may be done in combination with the removal of parts of the host or carrier and of contaminants.  Differs from “pest-free inputs” and sanitation which are directed at minimising the exposure of commodities to pests.
Remove contaminants
Ensure that the exported commodity is free of contaminants that could be hosts or vectors of pests.
Can be quantified experimentally or through post-production surveys. Needs to account for the biology of the pest.Audit of treatment records and processes. Effects of measures may also be auditable.Removal of contaminants is often a standard, post-production, commercial practice, and a standard import requirement. Differs from sanitation as it is specifically applied to reduce infestation rates in the consignment whereas sanitation is aimed at minimising exposure of the commodity to the pest.

Key references

  • Key references will be determined through consultation with biosecurity specialists and added here in the coming months.