he Senate will have a chance this week to push ahead with legislation that would require all drugs to be tested for safety and efficacy in children, not just in adults. This is the kind of worthy but narrow legislation that can easily get lost at the end of a session that is already running behind schedule and has been focused in recent weeks on a possible war with Iraq. As they struggle to catch up with overdue appropriations bills and other pending measures, senators need to speed the pediatric drug testing bill on to the House in a form that can readily win passage this session.

Legislation is needed because most of the drugs used in children in the United States have not been tested in children, despite the fact that their bodies metabolize drugs differently. Doctors typically cut the adult dose for children and assume the lower dose will work. Sometimes it does not, and sometimes it causes harm.

Congress sought to solve the problem five years ago with voluntary incentives that have spurred a lot of testing in children by the drug companies but have not ensured that all important drugs are tested. The Food and Drug Administration chimed in with a rule mandating tests in children for a wider range of drugs than those covered by the incentives program. Unfortunately, the agency's authority to do that has been challenged in court by conservative groups, and the Bush administration has been equivocal.

Congress needs to step in with legislation that ensures that all relevant drugs and biological products are tested in children. A bill sponsored by Senators Hillary Clinton, Mike DeWine and Christopher Dodd would codify the key components of the existing F.D.A. rule. It has been approved unanimously by a Senate committee and may be brought to the floor this week. Any senator who tries to block its progress should be held accountable for endangering the health of children.