The United States stands at the brink of a new arms race--a race to make and stockpile new chemical weapons of war, according to government and academic panelists at the annual meeting of the American Association for the Advancement of Science.

After years of hopes that a treaty banning all chemical warfare could be created, after years in which several countries, including West Germany, renounced all use of the weapons, the "world now finds itself on the threshold of a chemical arms race," said Arthur Westing, a professor of environmental science at Hampshire College near Boston.

"Yes, there is a real risk now of a chemical arms race," said Robert Mikulak, physical science officer with the federal Arms Control and Disarmament Agency.

Mikulak blamed the possible arms race on the Soviet Union, while Westing placed the responsibility largely on the United States.

Westing said the United States wants to build and stockpile chemical weapons, and has used propaganda to create a climate in which Congress would build more and better ones for fear that the Soviets might be doing the same.

He cited the U.S. charges that the Soviet Union has waged chemical war in Afghanistan and that others have waged chemical war with Soviet help in Laos and Cambodia.

Mikulak, on the other hand, said that what may trigger a chemical arms race is the failure of five years of U.S.-Soviet negotiations on a treaty. He said the major obstacle to that treaty was the Soviet unwillingness to allow American or neutral verification of their chemical war stocks.

Matthew Meselson, a biologist at Harvard University, analyzed the next U.S. step on chemical war: the decision to produce artillery shells with "binary" nerve gas containers. He said the United States has stockpiled several times as many conventional nerve gas shells as needed for a war in Europe.

Meselson said a U.S. decision to make binary shells might be simply "ineffectual posturing" that "might invite the very action it is intended to deter"--the Soviet buildup or possible use of chemical weapons.