the Agreement on Agriculture Part VI: Article 12 Disciplines on Export Prohibitions and Restrictions
1. Where any Member institutes any new export prohibition or restriction on foodstuffs in accordance with paragraph 2(a) of Article XI of GATT 1994, the Member shall observe the following provisions:
(a) the Member instituting the export prohibition or restriction shall give due consideration to the effects of such prohibition or restriction on importing Members’ food security;
(b) before any Member institutes an export prohibition or restriction, it shall give notice in writing（書面による通報）, as far in advance as practicable, to the Committee on Agriculture comprising such information as the nature and the duration of such measure, and shall consult, upon request, with any other Member having a substantial interest as an importer with respect to any matter related to the measure in question. The Member instituting such export prohibition or restriction shall provide, upon request, such a Member with necessary information.
2. The provisions of this Article shall not apply to any developing country Member, unless the measure is taken by a developing country Member which is a net-food exporter of the specific foodstuff concerned.
^ "Uncertainty about food availability can spark a wave of export restrictions, creating a shortage on the global market. Such reactions can alter the balance between food supply and demand, resulting in price spikes and increased price volatility. We learned from previous crises that such measures are particularly damaging for low-income, food-deficit countries and to the efforts of humanitarian organizations to procure food for those in desperate need." http://www.fao.org/news/story/en/item/1268719/icode/