Here are some facts about this fungicide, which is illegal for citrus in the United States but used in other countries for crops infected with fungal diseases, such as mold, mildew and rot.
WHICH COUNTRIES ALLOW IT?
* In the United States, carbendazim is approved as a fungicide in paints, adhesives, textiles and ornamental trees. It is not approved for food products.
However, another fungicide that is used on food products, thiophanate-methyl, breaks down into carbendazim after application. The Environmental Protection Agency (EPA) thus allows small amounts of carbendazim on 31 kinds of food, including grains, nuts and some fruits like strawberries -- but not on citrus.
The EPA said it approved carbendazim for citrus in Florida from 2002 to 2008 to fight black spot, a type of mold that grows on orange trees. But after that period, other alternatives became available and carbendazim was taken off the market.
A company must apply to the EPA for permission to have small amounts of carbendazim on citrus, but the EPA said no one has done so. Without official approval, any detectable amount of carbendazim on citrus is illegal.
* The European Union does not allow carbendazim as a fungicide on oranges, but does allow residue of the chemical on several kinds of fruits, vegetables and nuts. On oranges, the maximum level allowed is 200 parts per billion (ppb). In the United States, the levels found in orange juice were from 10 to 35 ppb, the FDA said.
The European Fruit Juice Association said there have been no problems reported about carbendazim in orange juice.
* Brazil has used carbendazim on citrus fruit for over two decades to combat blossom blight and black spot, the orange tree mold. Brazil's citrus producers' association said black spot has always been a problem for its orange crop but has expanded to worrying levels in recent years.
* Australia proposed banning carbendazim for almost all agricultural products in 2011 because of public health concerns. It also extended health warnings on the fungicide to show it can cause birth defects and male infertility in laboratory animals.
IS IT DANGEROUS?
* The EPA has said the fungicide levels found in orange juice in the United States are 1,000 to 3,000 times below levels that would pose a health risk.
The U.S. Department of Agriculture tested various foods in the United States for carbendazim residue, and found amounts as high as 1,500 ppb on blueberries and 700 ppb on green beans - although average amounts were much lower.
Kathryn Gilje, co-director of the Pesticide Action Network, said the fungicide is a possible carcinogen and can disrupt human hormone systems even at low levels of exposure.
Michael Hansen, chief scientist at Consumers Union, said carbendazim was also an aneugen, meaning it interferes with cell division and can cause mutations.
The World Health Organization has said risks are high only if large doses are ingested.