During a meeting in Hanoi to discuss the spread of the Zika virus, health officials confirmed that the larvicide imported from Brazil is only used treat wastewater, not drinking water.
They said the chemical will be suspended immediately when there is clear scientific basis connecting it to microcephaly.
A report recently released by Argentinian doctors suggested pyriproxyfen, not Zika, may cause a spike in babies born with microcephaly.
|Aedes aegypti mosquitoes are seen inside Oxitec laboratory in Campinas, Brazil, February 2, 2016
“In the area where most sick persons live, a chemical larvicide producing malformations in mosquitoes has been applied for 18 months, and that this poison (pyroproxifen) is applied by the State on drinking water used by the affected population,” the group said in its report.
Experts are still debating the validity of this claim.
Much too remains unknown about Zika, including whether the mosquito-transmitted virus actually causes microcephaly. The World Health Organization believes the suspected link could be confirmed within weeks.
Brazil is investigating more than 4,300 suspected cases of microcephaly. Researchers have confirmed more than 460 of these cases as microcephaly and identified evidence of Zika infection in 41 of them.
After the report of the Argentinian doctors, Rio Grande do Sul, a state in southern Brazil, on February 13 suspended the use of pyroproxifen.
However, the federal government dismissed the fears, insisting there had been no scientific study to prove that pyroproxifen is to blame.
The Zika virus has not been detected in Vietnam.