In an announcement that stunned scientists, the U.S. Environmental Protection Agency has cancelled grant applications for what was supposed to be a $20-million, four-year green chemistry program.

The mysterious cancellation, announced on Friday, came less than three weeks before the April 25 deadline for the grant proposals.

The federal grants, which were supposed to fund two new academic centers, would have been a major new source of funding for green chemistry, a field that seeks to design environmentally friendly chemicals and processes that can replace toxic substances.

The requests for proposals may be reissued, the EPA said Monday. But the program's sudden halt and uncertain future — and lack of explanation — have left scientists disheartened. Research labs had worked for months on their proposals and scientists now fear their hard work will be wasted.

"My reaction is shock that it happened and total dismay that what appeared to be a novel program was cancelled without warning or explanation," said Eric Beckman, a chemist at the University of Pittsburgh who was working on a proposal.

Terry Collins, a green chemist at Carnegie Mellon University and a pioneer in the field, said the announcement “stunned me.” Collins was on a team of green chemists and other environmental scientists that had been working for months to put together a funding proposal.

Beckman said he's never seen such a thing happen before — a government agency pulling the plug on a request for proposals so close to its deadline — in his more than 20 years in academia.

The $20 million in funding would be "one of the most significant sources of dedicated support for green chemistry so it is a blow to the community that the call for applications was cancelled without explanation," said Evan Beach, a green chemist at Yale University. "Everybody was in the home stretch on writing. The preparations took several months."

The EPA offered no reason for the last-minute cancellation.

“Given the new and emerging research areas… EPA determined that it was necessary to further explore these research areas and also consider changes to its usual review process," Kelly Widener, assistant director for research communications at EPA's National Center for Environmental Research, said in an email response to Environmental Health News.

Widener said the EPA anticipates re-issuing its requests for proposals in June or July.

Green chemistry, according to the EPA, is "the design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances…across the life cycle of a chemical product, including its design, manufacture, and use."

The new program -- to create Centers for Material Life Cycle Safety and Centers for Sustainable Molecular Design -- was announced in late December as a part of the EPA's Science to Achieve Results (STAR) program.

The green chemistry centers were to draw together scientists from wide-ranging disciplines, including engineering, chemistry, social science and physics, to develop "improved methods for the design of next generation chemicals," the EPA said when it announced the available funding.

"This holistic approach to design, which considers all the stages of a material's life cycle, provides an opportunity to produce materials which minimize, and preferably eliminate, any associated potential environmental and human health impacts that may occur during the life cycle," the original request for proposals said.

That funding for such a promising area of science was halted without explanation has many researchers scratching their heads.

"For the EPA to treat so wastefully the field that holds most of the keys to a good future for the relationships between chemical products and processes and the environment and health is mystifying to say the least," Collins said.

This article originally ran at Environmental Health News, a news source published by Environmental Health Sciences, a nonprofit media company.