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.
Biorat's backers admit it has disadvantages: it is more expensive than most of its chemical competitors and needs to be refrigerated, adding to costs for distributors. But it has captured market share in several regions, something helped by government subsidies toward its purchase when it first hit the market 10 years ago, according to Suu.
There is so far little sign of Biorat getting much traction in Asian markets, even with the backing of the Cuban diplomats who are tasked with promoting it via its embassies in the region. Biorat demonstrations have been held in the Philippines and Indonesia, but so far its sales push has only resulted in one import license, that of Malaysia, according to the company.
Most of the 2,000 tones the factory and 100 workers produce each year is shipped to Angola, Biorat's number one market and a country that the Castro regime gave massive military, humanitarian and development support to from its 1960s independence struggle onwards. The company declined to reveal its global revenues.
At least one other Labiofam product has run into problems. The marketing of its larvacide as a major weapon in the battle against malaria in Africa has been criticized by international health organizations, which says larvacides have only a limited role to play.
"They do a very good job in getting governments to pay a lot of money for products that appear to be deficient," said Maria Werlau, a Cuban-American analyst from the U.S.-based Association for the Study of the Cuban Economy and a critic of President Raul Castro's government. "You don't have the same kind of accountability (in Cuba) that there is in other countries. There is no way to scrutinize what is going on. That's why they market these products in the developing world."
Rats have been feasting in Asia paddy fields since famers began cultivating it around 12,000 years ago, but an increase in the number of yearly harvests in many regions has meant more for them to feed on. As rat numbers increase, so does the economic cost: a loss of just 7 percent of Asia's rice crop is enough rice to feed 245 million people for 12 months.
Farmers in Vietnam often build plastic fences around their plots, which can protect them but only shifts the problem to neighbors. Trapping and electrocution, supposedly banned because of the risks posed to farmers of accidental electrocution, are common, but for many farmers poison is the weapon of choice, either routinely or when an infestation strikes.
Cao Thi Huong has been using Biorat for more than 10 years, spending around $30 on treating her small plot two times a year. She lives close to Suu's house, where boxes of Biorat are kept in large refrigerators at the back of the garden close to a chicken coop. "Personally speaking, I think it's better than the chemical," she said.