Ten years ago yesterday, 140 scientists ended four days of debate in a rustic California church and agreed, in a dramatic consensus, to regulate their own work in a new and potentially hazardous form of genetic engineering.

Research using "recombinant DNA" technology -- the ability to cut and splice bits of genetic material from different organisms in combinations not found in nature -- should go forward, said the group, but only under strict new safety guidelines.

The so-called Asilomar meeting was hailed at the time as a model of scientific self-regulation and social responsibility, a unique experiment in which researchers took the initiative in policing their own work before, rather than after, problems set in.

Today the debate has subsided and many scientists believe in retrospect that it overestimated the dangers of genetic engineering and underestimated its potential good. But on balance, the Asilomar organizers say, their experiment was a benefit to science.

By coincidence, the man who presided over the historic and sometimes stormy meeting at isolated Asilomar Conference Center exactly a decade ago -- Stanford University biochemist Paul Berg -- was in Washington yesterday to be honored by President Reagan.

Berg and 18 other scientists or their families received the National Medal of Science in a White House ceremony presided over by the president and Vice President Bush.

Now 58, Berg was cited for his "fundamental contributions" to recombinant DNA work and his "deep concern for its safe and humane application to medicine."

Berg, who won the 1980 Nobel Prize in chemistry, said in a recent interview that although the Asilomar experiment in self-regulation worked, the development of genetic engineering turned out quite differently than anyone anticipated.

He and others say the safety concerns of a decade ago -- including scenarios of possible cancer-causing microbes escaping from the laboratory -- "clearly turned out to be unrealistic." In contrast, they say there was a "gross underestimation" of the potential benefits to come for medicine and agriculture.

Meanwhile, across town yesterday, the practical benefits of gene-splicing technology were further extolled at a biotechnology conference in the futuristic domed auditorium of the National Academy of Sciences.

Academy president Frank Press said research advances in the l0 years since Asilomar have been "mind-boggling." Alexander Rich, a Massachusetts Institute of Technology biophysicist, noted that within the scientific community Asilomar now draws mixed reviews.

While many view it as an exercise of "scientific statesmanship," others believe that it was a "mistake, that scientists overreacted." Rich noted that in the decade since there have been hundreds of thousands of experiments conducted without as much as a sniffle resulting.

"All of the scare scenarios were in fact erroneous," said Rich.

After Asilomar, the safety suggestions were translated into National Institutes of Health guidelines. But they have been downgraded over the years, and most laboratory experiments are now conducted using far less restrictive standard microbiology techniques.

While most of the debate about recombinant DNA risks has ended in the scientific community, the field is still under some public attack from critics who urge that more attention must be paid to the effects of releasing genetically engineered organisms into the environment as well as to the future implications of human gene therapy. While these concerns generally are not shared by the Asilomar organizers, some scientists still worry privately about possible biological warfare research -- though they see no convincing evidence that such work is under way here or abroad.

Looking back, Berg defended the Asilomar effort as "something that was significant and necessary because I don't think anybody could say with assurance what would happen."

He and other Asilomar organizers believe that in initiating the public debate, the scientists fared far better than they might have otherwise, avoiding more restrictive national legislation and allowing the research to go forward, slowly at first and picking up speed.

"It allowed things to move forward in a rapid and constructive way," said Dr. Maxine Singer, of the National Cancer Institute. Nobel Laureate David Baltimore said Asilomar was a "coming of age" in which "biology lost its innocence," emerging from the ivory tower to help guide recombinant DNA research safely out of the laboratories into more widespread use.

But Berg says that one of the things he is "sorriest about" is that the experience with recombinant DNA did not result in a permanent national mechanism for overseeing other new technologies and the problems that might emerge, a "standing group with effective antennae . . . tuned into things emerging that would have impact on society."