The agency's Center for Veterinary Medicine released a preliminary finding of no significant impact for the field trial on a method that aims to reduce populations of the mosquito that spreads dengue, chikungunya and the Zika virus among humans.
A residents' group called the Florida Keys Environmental Coalition wants the district to instead try infecting mosquitoes with a bacteria that curbs their ability to transmit disease, arguing that Oxitec's proposal is mostly marketing hype and won't be subject to adequate federal oversight.
Anti-GMO activists have criticized Oxitec's trials, saying more proof is needed that stray female modified mosquitoes that leave the labs aren't spreading genetic material through bites or that there are no other environmental risks, such as opening areas to infestation by another disease-carrying mosquito species.
In its preliminary finding, the FDA said it was "highly unlikely" that humans or animals bitten by female modified mosquitoes would be exposed to synthetic genetic material, and any bites wouldn't be any different from bites made by a wild mosquito.
"Based on the data and information submitted in the draft (environmental assessment), other submissions from the sponsor, and scientific literature, FDA found that the probability of adverse impacts on human or other animal health is negligible or low," the finding said.
