The law, approved by voters Nov. 4, bans cultivation and experiments with genetically modified organisms, or GMOs.
The agricultural giants filed a lawsuit Thursday in federal court.
The companies seek to prevent the law from going into effect and invalidate it altogether.
“This local referendum interferes with and conflicts with long-established state and federal laws that support both the safety and lawful cultivation of GMO plants,” said John Purcell, vice president of Monsanto Hawaii Business and Technology Lead.
Monsanto, Dow and other agricultural entities spent a record $8 million on a media campaign fighting the measure, which passed by about 1,000 votes; some 45,000 votes were cast.
Purcell said “the referendum will have significant negative consequences for the local economy, Hawaii agriculture and our business on the island. We are committed to ongoing dialogue as we take steps to ask the court to declare that this initiative is legally flawed and cannot be enforced,” Purcell said.
U.S. Magistrate Judge Barry Kurren will oversee the case. He ruled this year a law in Kauai County, which regulated genetically modified crops, invalid because state law superseded the measure.
The same agricultural companies looking to nullify the Maui County law challenged the move.
The federal lawsuit was filed one day after the initiative’s backers filed a lawsuit in state court, seeking to ensure the law is implemented by Maui County after the election results are certified.
Hawaii is an important world headquarters for Monsanto and Mycogen Seeds, companies owned by Dow Chemical and other agricultural giants. About 90 percent of America’s corn was developed in research units on Maui, Kauai and Oahu.
In a statement, Vote Yes Maui said, These companies are at war with the land and utilizing the climate, water and lack of regulation to their private benefit and profit, with no obligation to make reparations for the depletion of the soil, the chemical residue and drift, the pollution of waterways, the runoff into reefs, nor the impacts to the health and quality of life of those families who reside in the vicinities of their operations.”