Africa Accelerates Methyl Bromide Phase-Out Ahead of the 2015 Deadline

Training on Phosphine Fumigation to Enhance Food Security in Africa

Douala, Cameroon, 8 - 10 October 2012- Phosphine fumigation training was held in Cameroon from 8-10 October 2012 to enhance food security in Africa. The training which was aimed at demonstrating available methyl bromide alternatives for management of stored grain pests, analyzed the different alternatives, their application, efficacy, cost, availability, green-house warming potential, registration, phytotoxicity, and corrosiveness. 

Several African countries have accelerated their methyl bromide phase-out ahead of the deadline following the Methyl Bromide (MB) Phase-out that is scheduled for 1st January 2015. With only two years left to ensure compliance with the phase out target, some countries face MB phase-out challenges that stem from the non-sustainability of adopted alternatives. Training is needed in some countries on suitable alternatives such as phosphine fumigation which is a fumigant in agriculture, for pest control in structures and stored commodities, and for quarantine treatments.

The three day training was opened by Mr. Peter Ayuk Enoh, Director of Standards and Control, who is also the National Ozone Officer and was attended by over sixty participants from grain storage sectors, certified storage organs, national syndicate of fumigators from public and private sectors, and phytosanitary sectors.

Ms. Florence Asher highlighted the issues faced by the industry which included pest resistance to fumigants.  She demonstrated the different types of resistance including behavioral, penetration resistance, metabolic resistance, and altered target site resistance. Further in her presentation, she established the causes of resistance, like misuse/malpractice, unsuitable fumigation structures, lack of appropriate equipment, lack of technical skills, and poor storage management.

Some of the fumigant alternatives presented in the training included Phosphine,  Sulfuryl fluoride, controlled/modified atmosphere, Carbonyl sulphate, ethyl formate, hydrogen cyanide, inert dusts, and Integrated Pest Management.  Among all these, Phosphine is considered as an economic, viable, and available option to Methyl Bromide alternative, and knowledge of its correct application was paramount to the training. 

“In order to kill grain pests at all stages of their life cycle (egg, larva, pupa, adult), including pests with strong resistance, phosphine gas concentration levels needs to reach and be maintained at 300 parts per million (ppm) for seven days (when grain is above 250C) or 200 ppm for 10 days (between 15-250C). The total time required for fumigation ranges from 10–17 days accounting for the minimum exposure period, ventilation and withholding period.” Ms. Asher explained.

Some challenges were highlighted that included lack of suitable infrastructure for effective phosphine fumigation and quality fumigation plastic sheets. Existence of many porous borders was also another challenge as many adulterated phosphine formulations are imported into Cameroon as there is lack of enforcement of regulations on quality control. 

In the end, the participants agreed that there is a need to develop other sustainable alternatives for postharvest due to insect resistance to phosphine fumigation as well as its high operational costs, long exposure period, lack of suitable infrastructure/ fumigation experts, and lack of fumigation code of practice/product. In addition, continuous training of Pest Control Personnel is necessary to enhance technical capacity in good phosphine fumigation in bagged, concrete and metal silos fumigation.

It is also important to provide assistance to up-grade/refurbish existing infrastructures to make phosphine fumigation viable; develop/review regulatory frame work (fumigation code of practice/product) to prevent malpractices which poses a very big risk on insect pest resistance and implement quality control programmes for phosphine formulation; and to create public awareness on MB phase-out to public-private sector.

For more information, please contact:
Ms. Florence Asher, Regional Methyl Bromide Officer, Regional office for Africa, United Nations Environment Programme, OzonAction; Email:, Tel: +254-20 762 3337

Notes to Editors:
Methyl bromide is widely used as a fumigant in agriculture, for pest control in structures and stored commodities, and for quarantine treatments. Fumigation is a technique that allows the gas to reach pests which are in soil, in durables, in perishables, and in structures and vehicles. This chemical controls a wide range of pests, including pathogens (fungi, bacteria and soil borne viruses), insects, mites, nematodes and rodents. Methyl bromide is an ozone depleting substance that is controlled under the Montreal Protocol. With support from the Protocol's Multilateral Fund and the Global Environment Facility, developing countries and countries with economies in transition are reducing and ultimately phasing out their consumption of this chemical. Use of methyl bromide can be reduced and eliminated by adopting alternatives, which have been identified for more than 90 percent of applications.
The Montreal Protocol is an international treaty designed to protect the ozone layer by phasing out the production and consumption of a number of substances believed to be responsible for ozone depletion. The treaty was opened for signature on September 16, 1987 and entered into force on January 1, 1989. Since then, it has undergone five revisions, in 1990 (London), 1992 (Copenhagen), 1995 (Vienna), 1997 (Montreal), and 1999 (Beijing).

UNEP News Release 2012

Group photo of the delegates during the phosphine fumigation training