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Annex

Guideline: Application requirements for Hot water dipping

Effective 6 September 2022

Fruit fly management using hot water dip treatment (HWDT)

Mangoes must be treated prior to export by submersion in hot water under the supervision of an officer authorised by the National Plant Protection Organisation (NPPO).

  1. Hot water dipping facilities must be registered with the exporting NPPO.
  2. The exporting NPPO is required to ensure that registered treatment providers are suitably equipped and have systems in place to carry out the treatment in accordance with the agreed protocol or work plan between the exporting NPPO and the department.
  3. Approved facilities are listed on BICON or on exporting NPPO websites.
  4. The approved treatment schedule for HWDT is listed below.
  5. Fruit must be pre-sorted by weight class prior to treatment and submersed according to the approved treatment schedule.
  6. Hot water dipping treated fruit must be packed into cartons under insect proof conditions.

The treatment schedule for HWDT is as follows:

Fruit weight (grams)

Water temperature

Dip time*

up to 500 grams

48°C

60 minutes

500 to 700 grams

48°C

75 minutes

701 to 900 grams

48°C

90 minutes

*dipping time must be extended for an additional 10 minutes if hydro-cooling starts immediately after the hot water immersion treatment.

  1. The temperature 48°C or higher must be reached before the treatment time starts.
  2. The fruit pulp temperature must be 21°C or above prior to treatment commencing.
  3. Fruit must be submerged at least 10 centimetres below the water surface.

  4. Water must circulate constantly and remain at 48°C or above throughout the treatment period.

    4.1. During the first five minutes of treatment, temperatures may be allowed to fall as low as 47.4°C provided the temperature is at least 48°C at the end of the five minute period.

    4.2. For treatments lasting 60 minutes, temperatures may be allowed to fall as low as 47.4°C for not more than 10 minutes during the treatment period.

    4.3. For treatments lasting 75 to 90 minutes, temperatures may be allowed to fall as low as 47.4°C for not more than 15 minutes.

  5. Only packing sheds with combined on-site packing and screened treatment facilities may pack fruit for Australia.
  6. All activities within packing sheds will be subject to supervision by an officer authorised by the National Plant Protection Organisation (NPPO).