The EPA has issued a moratorium on use of a type of pesticide theorized to be responsible for plummeting bee populations. Neonicotinoids are a class of common pesticides that recent research has pointed to as being harmful to birds, bees and other animals. The EPA previously approved their use, but outcry over the damage being done has caused the agency to reverse course while more studies are done. On Thursday, the EPA sent letters to people and companies that have applied for outdoor use of the pesticide, saying that new use permits won’t be issued.

New uses of neonicotinoids will no long be approved “until the data on pollinator health have been received and appropriate risk assessments completed,” the EPA letter reads. Existing permits to use them, however, will not be rescinded — something wildlife and environmental advocacy groups are unhappy with.

“If EPA is unable to assess the safety of new uses, the agency similarly is not able to assess the safety of the close to 100 outdoor uses already approved,” said the Center for Food Safety’s Peter Jenkins in a statement criticizing the EPA’s actions. Other organizations of beekeepers, environmentalists, and farmers echoed the sentiment.