An application to discharge methyl bromide into the air at the Port of Tauranga has been declined.
The discharge of the gas was in relation to the pre-shipment fumigation of export logs.
The application, made by Envirofume Limited to the Bay of Plenty Regional Council, was declined by an Independent Commissioner on the grounds that methyl bromide was known, or suspected, to cause significant adverse effects on human health.
The gas is odourless, colourless and heavier than air and is classified as "acutely toxic - fatal" and could cause cancer, genetic mutations and neurological disorders.
The commissioner, Rob van Voorthuysen, said there was no certainty that the proposed discharge of the gas would meet the mandatory tolerable exposure levels set by the Envrionmental Protection Agency.