CONGRESS SHOULD GRASP the opportunity that will be offered this week to reconsider the question of chemical warfare.Both the House and Senate have appropriated money to build a facility for the production of a new type of chemical weapon called binaries. If allowed to stand, that decision would usher in a generation of more dangerous -- because they would be more usable -- chemical weapons, launch program that could cost up to $4 billion, and dim hopes of reaching agreement on a treaty to ban chemical warfare.

Because of modern defensive measures, chemical weapons are of minimal military usefulness against a prepared opponent. The victims of its use will be primarily civilians. If the weapons are used as intended in heavily populated Europe, casualties could number in the millions, while leaving the Soviet armies, which are fully equipped with protective gear, relatively unaffected. Largely for this reason, the NATO allies oppose chemical warfare and, with the reluctant exception of West Germany, do not allow the United States to store chemical munitions on their soil where they would be available for use.

Negotiatiuons have been under way since 1977 to formally ban research, production, stockpiling and use of chemical weapons. The means of verifying compliance with such a ban is the sticking point. Resumption of chemical weapons production is therefore hardly a useful 'bargaining chip' to move the talks forward, as its proponents argue. It is far more likely to end realistic hopes for an agreement.

So far, Congress has not seriously looked at the pros and cons of a return to chemical weapons production after an 11-year moratorium. No hearings on the subject have been held since 1975 -- two years before the arms control talks began. Before taking these early steps, Congress should establish whether chemical weapons actually improve or undermine national security. This is no subject for easygoing, aimless policymaking.