A new effort by industry leaders and others to engender public trust in nanotechnology, the young science of making invisibly small materials, has run into difficulties on the eve of its first meeting after environmental and citizen groups declined to join for now because of doubts the initiative will serve the public interest.

None of the three invited representatives of environmental groups has agreed to join the newly created International Council on Nanotechnology at its inaugural meeting in Houston today.

One said yesterday that he had asked that his name be removed from the membership list because the group -- funded almost entirely by industry -- seemed more interested in easing public jitters than in actually doing something about the potential risks of nanotechnology.

The early rift is emblematic of the difficulties facing the new science as it strives to gain public acceptance. The field, expected to become a trillion-dollar industry by 2012, promises a host of technological and medical advances. But it has also stirred fears because some of its tiny products appear to be toxic and many are not covered by environmental and occupational health regulations.

Nanoscientists and activists alike have said they want to avoid a replay of the debacle over genetically engineered food, widely viewed as a classic case of an emerging science that squandered an opportunity to gain public trust. But the troubles already facing nanotech's first efforts at conciliation indicate that the nascent field is still struggling with its image.

"The trust hurdle is probably the most critical right now," said David Rejeski of the Washington-based Woodrow Wilson International Center for Scholars.

"There's a lot of work to be done to get all the players in the room," said Rejeski, who likened the current state of affairs to a junior high school dance in which everyone is awkwardly wondering who will be the first to take the floor. "It's kind of a social experiment."

Nanotechnology deals with products less than 100-billionths of a meter in size -- a few 10,000ths of the diameter of a human hair.

Some of the materials being created, such as cages of carbon atoms known as buckyballs, show promise as tools for environmental cleanup. Others, such as carbon nanotubes, are expected to revolutionize the electronics industry. A few materials are already being used in medical tests, stain-resistant fabrics and sunscreens.

But the peculiar chemical and electronic properties exhibited by these materials can cut both ways. Early research has shown that some manufactured nanoparticles are toxic in mice and fish. A recent report from Swiss Re, the giant Swiss insurance company, expressed grave concerns about liability issues that could arise from nanotech products. And a July report issued by Britain's Royal Society and Royal Academy of Engineering concluded that some nanoparticle-containing cosmetics and sunscreens ought to be removed from the market because of health risks.

The council, to be based at Rice University in Houston, was created to bring together industry, government, and environmental and social organizations to identify nano-issues before they become problems and to quickly fund needed research.

"We think there is a need to create a new mechanism for these people to work together," said Kristen Kulinowski, executive director of Rice's Center for Biological and Environmental Nanotechnology and a co-founder of the group. She added that she hopes citizen groups will overcome their reluctance.

With about $500,000 in industry donations, the council hopes to answer questions about risk and advise governments on how best to regulate the new substances.

The attempt at preemptive cooperation drew praise from some who have opted to join.

"It seems to me if we create an organized space for these different interests to find common ground, that bodes well for a much less contentious development for the technology," said Davis Baird, chairman of philosophy at the University of South Carolina and associate director of that university's NanoCenter.

William Provine of DuPont Co., a major developer of nanotech products, was also upbeat. "There's no crisis here," he said, referring to current safety concerns. "But we also want to be respectful and say, 'Not everything is known.' "

But others said they were chary. Jennifer Sass of the Natural Resources Defense Council, who was invited to join but will not participate for now, said the group's "heart is in the right place" but worried that it "may be heavily influenced by industry because that's where the funding is coming from."

Scott Walsh of Environmental Defense in Washington, who will attend to listen but not as a member, expressed similar concerns.

And Pat Mooney of the Ottawa-based citizen's organization ETC Group said he had declined to join. "The whole tone of the approach is 'How can we convince society we're nice guys?,' and that's just not going to fly," he said.

Mooney was also critical of the group's claim to be "international."

"It doesn't cut it to have Mitsubishi from Japan and L'Oreal from France. Two-thirds of the globe is left out in this process," including most of the world's poor, he said.

Mooney and others expressed more confidence in a broader effort being organized by the Dillon, Colo.-based Meridian Institute, funded by the Rockefeller Foundation and a Canadian public corporation. The Global Dialogue on Nanotechnology and the Poor will focus on environmental and health concerns but especially on nanotech's potential to help developing countries, such as by cleaning up water and making cheap electricity.