HANOI, Vietnam (AP) -- His wares banned in much of the world, the Vietnamese salesman hawking a rat poison laced with salmonella sought to prove the bait was as safe as claimed. He sliced open a packet with a pair of rusty scissors, dipped his finger into the sticky, bad-smelling rice, brought out a few grains and then chewed them gingerly.
"It tastes a little bitter, that's all," said Nong Minh Suu. He chose not to swallow the unhulled grains, instead spitting them out after a few seconds before lighting a cigarette. "When rats eat this, 100 percent of them will be killed. It is absolutely safe to human health."
Rat poisons normally come with warnings against human consumption and medical directions about what to do if accidentally eaten. Not so "Biorat," a bait produced in Vietnam by a Cuban-state owned company that earns foreign exchange for the Castro government.
The company claims the salmonella strain it includes is "harmless" to everything -- humans, the environment, pets and other animal species -- apart from rats. That is disputed by the Centers for Disease Control and Prevention, a U.S. federal government agency, and other international health institutions including the World Health Organization.
Biorat's production and sale in Vietnam is a legacy of the cozy ties between Cuba and Vietnam, two nations on opposite sides of the world but whose leaders are bound together by a public embrace of Communism. By operating here, the company, called Labiofam, can import ingredients free of any complications stemming from the U.S. trade embargo of Cuba that has been in force since the early 1960s.
It also gives it a base to try and enter new markets in Southeast Asia. The company is currently installing a new, automated production line at its Vietnam factory in preparation for a push in the region, where demand for rat poison is growing along with its population of rats, which nibble their way through at least 15 percent of the region's annual rice crop.
Labiofam produces an array of products alongside Biorat, from cancer treatments made from the stings of scorpions, larvacides that target mosquitoes, pesticides, even a probiotic range of yoghurt. They are marketed across the developing world, mostly in African and South American countries, where the company leverages government-to-government links forged in the Cold War and by the ongoing deployment of teams of Cuban health workers.
Salmonella, the name given to a group of bacteria, is the most common cause of food poisoning in the United States. In 2011, it was responsible for around 1 million illnesses and at least 29 deaths, according to the CDC. Most people infected with Salmonella develop diarrhea, fever, abdominal cramps, and vomiting. It is especially dangerous for young children and the elderly.
A strain of salmonella was used in rat poisons in Europe until the 1960s, but it was linked to several deaths and illnesses in humans, triggering the ban. Labiofam says it has isolated a different strain to that used in those preparations, but the CDC says its research shows it is the same. A 2004 report by the American agency even warned that it could be used in a bioterrorism attack.
"There are too many questions, why would you want to use something that has not been cleared by the CDC," said Grant Singleton, an expert on rodent biology and management at the International Rice Research Institute. "Its efficacy is questionable. I have not seen anything published in mainstream peer-reviewed scientific papers to demonstrate it's effective."
Singleton also pointed to an ingredient in the poison that its makers rarely mention: a small amount of warfarin, a chemical rodenticide in its own right, and suggested that it could be the agent that is killing rats. Company marketing literature refers to the chemical only as a "catalyst" though on the packet it is listed as warfarin.
The company said criticism of its product was a result of American hostility to the country and commercial jealousy. There are no documented deaths or illnesses as a result of using the product in Vietnam or other countries.
"It is quite complicated, but this all comes down to politics," said Gustavo Junco Matos, the head of the company in Vietnam, in an interview at a trade stand in Hanoi where the product was on display next to Cuba's better known exports: rum and cigars. "Ours is a biological product and only causes damages to rats."
The Vietnamese government, which controls all media in the country and doesn't allow for open discussion and criticism of its decisions, acknowledged that the product was banned in some countries, but said there was nothing to worry about. "We use it and find that it's effective and it's good in Vietnamese conditions," said Nguyen Xuan Hong, director of the plant protection department at the agriculture ministry.