First Session

Gold Coast, Australia, 4-8 May 1999


Table of Contents






1. This document represents the first attempt by the Secretariat to evaluate the economic implications of alternative treatments to methyl bromide (MB) for exports of tropical fruits. This includes, where information is available, the effectiveness of the treatments and the level of investment required to install the treatments. A major problem encountered in this study was the lack of data needed to conduct a systematic economic analysis of the alternative treatments, particularly to ascertain the volumes of tropical fruit exports that would justify such investments and the monetary and social costs and benefits involved. There were insufficient time (12 months between sessions) and resources to conduct an in-depth study, and therefore the analysis in this document relies solely on secondary sources. If the Sub-Group decided that an in-depth analysis was necessary, then appropriate arrangements, including cooperation agreements with national institutions and experts and field visits, would be needed to generate the required data.


2. MB is a fumigant that has been used commercially for more than 40 years to control pests such as bacteria, fungi, soil-borne viruses, insects, mites, nematodes and rodents. MB is an odourless, colourless gas and it has features which make it a versatile chemical with a wide range of applications, particularly as the standard treatment for a wide range of tropical fruit exports. However, in 1992 it was listed under the Montreal Protocol as an ozone-depleting substance, leading countries to impose restrictions on its use, with the objective of having its production ultimately cease.

3. The Parties to the Montreal Protocol, at their ninth meeting in September 1997 agreed that for developed countries a 25 percent reduction in the production and consumption (based on 1991 levels) would apply from 1 January 1999, a 50 percent cut from 1 January 2001, a 70 percent cut from 1 January 2003, and complete phase-out by 1 January 2005. A freeze on production and consumption (based on 1991 levels) had been applied from 1 January 1995. Some developed countries have accelerated the phase-out of MB (Denmark and Sweden agreed to a phase-out in 1998, Austria by 2000, the EC as a whole and the United States by 2001). For developing countries, a 20 percent cut in production and consumption (based on the average in 1995-98) would apply from 1 January 2005, and phase-out by 2015. A freeze at 1995-98 levels would apply from 1 January 2002.


4. Alternative treatments to methyl bromide are listed in Table 1. Where possible the following aspects are covered: description, commodities treated, effectiveness, investment and ongoing costs. For this analysis, the major tropical fruit exports include: avocado, papaya, mango, lychee, pineapple, guava, longan, durian, rambutan, cherimoya, carambola, passionfruit and sapodilla. Exports of these fruits are economically important to many countries, including Australia, India, Indonesia, Malaysia, Mexico, Philippines, China Province of Taiwan, Thailand, and many other countries of Africa, Asia and Latin America and the Caribbean. For these fruit, infestation by a wide range of pests occurs including internal and external feeders, Lepidoptera, mites and weevils, but fruit fly is the most significant.

Table 1. Alternative treatments to methyl bromide




Investment cost

Operating cost

1. Ethylene dibromide


Linked to cancer, and hence, effectively phased out.


2. Methyl iodide

Rapidly destroyed by ultra-violet light hence not considered a threat to the ozone. However, acts as a biocide similar to methyl bromide.

USDA tests in 1997 indicated its effectiveness against Caribbean fruit fly in guavas and papayas. Tests are being conducted to establish minimum doses required to meet quarantine rules and regulations.


3. Chemical dips

Approved treatment for the control of Australian fruit flies.

Accepted by New Zealand for Australian fruit imports. Hence, sets a precedent for similar imports from other countries.

US $10 000


4. Cold disinfestation

Fruit is cooled down to 0 degrees and held for 13-16 days.

Mainly used for temperate climate fruits.

An existing cold storage plant can be utilised.

Energy cost is very high, similar to heat treatments.

5. Hot water dips

Immerse in hot water at about 50 degrees Celsius.

Same as FHA.

All heat treatments effectively reduce self-life.

US$120 000.

Cool storage is also required.

Very high energy cost.

6.Forced Hot Air (FHA) treatment

Currently used for mangoes, and papaya exports.

The treatment is very effective on immature stages of fruit fly.

US$160 000.

A cool store is also essential.

Very high energy cost

7. Vapour heat treatment

Similar to the FHA treatment, but vapour heat uses humidity

As above.

As above

As above.




Investment cost

Operating cost

8. Controlled Atmosphere.

Control of temperature and humidity, as well as of oxygen, nitrogen, and carbon dioxide gases. .

Being tested for mangoes.

9. Irradiation

Ionising radiation passes through food without leaving any residue.

Most irradiation treatments for phytosanitary purposes do not kill pests but rather prevents their emergence (e.g. fruit flies) or cause their sterility.

About US$5 million.

US$200 000 per annum over 10 years (at a discount rate of 10 percent) and assuming a charge out rate for treatment of US$0.20/kg the breakeven quantity of fruit treated is around 5 000 tonne per year.

10. Others. Refer to document CCP: BA/TF 99/CRS.8.


5. Of the alternative treatments which have been, or are being tested, the more promising ones for tropical fruit appear to be heat treatment (dips, vapour and forced air) and waxing. Other treatments are accepted by the mainland United States (namely, irradiation and cold treatment) but only for fruit originating from Hawaii. Information is provided below of the status for two of the major tropical fruit markets which have extensive experience in the areas of pest and disease control, Japan and the United States.

a) Existing alternatives

6. Japan accepts mango imports from the following countries subject to the treatments specified: heat treatment for mangoes from China Province of Taiwan, the Philippines, Thailand, Australia, and Fiji. Japan accepts 15 days cold treatment for control of Caribbean fruit fly on carambola exported from Florida. Papayas exported from Hawaii and the Philippines and mangoes from the southern islands of Japan are treated with moist heated air (vapour heat treatment) to control Medfly, Melon and Oriental fruit flies. Lychees imported from China are treated with a combination of vapour heat and cold treatment to control Oriental fruit fly.

7. The United States accepts hot-water immersion treatments of mangoes potentially infested with Mediterranean and Mexican fruit fly imported from Mexico, the Caribbean and Central and South America. Carambola can be cold treated also as a disinfestation treatment for fruit flies when exported from Hawaii to the mainland United States. Hawaiian-grown papayas, carambola and lychees may be irradiated as a quarantine treatment for shipments to the United States mainland. This regulation is limited to the movement of Hawaiian products to the United States mainland. Currently, no other country has adopted irradiation as a quarantine treatment. Waxing of cherimoya for pest control is accepted for imports by the United States from Chile.

b) Potential alternatives

8. Heat (as immersion in water) has been considered for controlling some species of fruit flies in guava, carambola, mango and papaya particularly for the Papaya fruit fly found from Mexico to Brazil. Heat treatments are under development in Hawaii for mango and lychee and for rambutan in combination with sulphur dioxide prior to heat treatment for red colour retention. For lychee, a test using 100 000 Medfly larvae, the most resistant species and stage of fruit fly found on lychee in Hawaii, showed that quarantine security was only possible after 16 days but fruit quality was damaged. Film wraps to control fruit fly may be feasible for papaya and other tropical fruit exports. A film wrap treatment for guavas, carambolas and mangoes is under investigation.


9. The regulations governing treatments that apply to tropical fruit are usually complex and often difficult to understand and apply, sometimes giving rise to concerns about their actual justification. Exporting countries which lack trained people and technical resources are at a disadvantage in understanding and meeting importing market requirements.

10. From the perspective of importing countries that also export, the cost of accidentally importing a pest can be a significant loss of trade if the pest becomes established and the country's own exports are based on area of freedom or area of low pest prevalence. Based on information provided by the Methyl Bromide Technical Options Committee (MBTOC) under the Montreal Protocol, control or eradication measures to deal with an imported pest can cost anything from US$5 million to US$100 million annually over successive years. For these reasons, a large number of pests are of concern to phytosanitary authorities in importing countries, who often require a mandatory disinfestation treatment prior to export. Any disinfestation treatment requires official approval by the regulatory agencies in each country, based on scientific data to ensure an adequate level of confidence in its efficacy.

11. In the majority of cases, disinfestation in the country of origin or on arrival has relied on MB. For the past 40 years and until the early 1990s, there was little consideration of alternatives to MB for these uses. Many alternative disinfestation treatments have been developed, but none of them have been found suitable for ship-side treatment of a large range of commodities. Ideally, alternatives that replace MB for "on entry" applications should be of short duration and capable of being carried out on site. "On entry" treatment remains one of the most important areas where substitution of MB will be difficult.

12. There is concern among some developing countries that imports of fresh tropical fruit treated with MB may be restricted by those countries which are phasing-out the use of this fumigant. Such a situation would render the 10 years' grace period (up to 2015) ineffective.

13. Economic, logistical, and engineering considerations are key factors in deciding the acceptability of a disinfestation treatment. Developing effective disinfestation treatments that do not significantly reduce commodity marketability is an important priority. Therefore, it is prudent that cost-effective alternative treatments be identified and tested at least before the phase-out of MB in major markets. The Sub-Group may wish to consider encouraging a comprehensive analysis of alternative treatments. The potential for acceptance of an alternative treatment should be determined by comparing the costs and benefits of MB with alternatives, including the "no treatment" option. If an alternative is to be adopted it must be practical to apply, its effectiveness capable of being documented, cost effective (determined by the equipment and operating cost) and result in acceptable levels of residues.

14. As mentioned in the introduction, if the Sub-Group decided that an in-depth analysis was necessary, then appropriate arrangements, including consultations with the MBTOC and cooperation agreements with national institutions and experts dealing with tropical fruits would be needed. Therefore, the Sub-Group may wish to devise a questionnaire to provide basic information on current facilities including infrastructure and costs (capital and operating) and advise its members to provide the Secretariat with contact points in their countries.