The U.S. ambassador said that Costa Rican lab workers made an error when they conducted tests for harmful fungus on a boatload of rice imported from the United States.
The ambassador, Anne S. Andrew, said that test results show that the rice is not harmful if it is milled and the husks removed.
The case involves some $35 million in imported rice, some 4,800 tons. The Ministerio de Salud has ordered that the rice be destroyed by burning. Testing was done at the universidad de Costa Rica. Ms. Andrew said that the rice was not milled when it arrived and was not ready for human consumption.
The dispute involves tests in which part of the rice showed levels of aflatoxins higher than permitted. The naturally occurring toxins can cause cancer.
Ms. Andrew said that the embassy obtained samples of the rice and sent them to two private labs in the United States. Both labs removed the indigestible husks and tested the remaining grain. Ms. Andrews said in a letter to a legislative deputy that the labs found levels of aflatoxins to be well within the limits for human consumption.
She also said that the rice arrived by ship from the United States Oct. 27 from KBX, Inc., in Benton, Arkansas. She said tests conducted by the private labs on hulled rice showed aflatoxin levels of less than 20 parts per billion.
She said that rice generally is sold at retail with the husk or hulls removed. If there is aflatoxins present, it usually is on the hulls, she said.
The ambassador said the embassy would share the results with the health ministry. Her letter was written Thursday.
Aflatoxins are produced by fungus. Two local companies, Pelón and DEMASA, own the rice. Rice is first milled to remove the hull and to produce brown rice. The white rice typical of the dinner table comes with more milling.
Local rice producers earlier had expressed pleasure at what they said was contaminated rice. The importation of rice is a sensitive political issue because rice on the world market usually is available at prices lower than Costa Rican farmers can produce it. It was the Asamblea Nacional de Productores de Arroz that raised the issue.
A Spanish study published in 2007 showed that hulling reduced the level of aflatoxin some 97 percent on artificially infected rice that was then processed.