Out of step at the UN

The Reagan administration has once again demonstrated its diplomatic ineptness at the United Nations. Recently, by a vote of 146 to 1, with no abstentions, it went down to glorious defeat in the UN General Assembly over a resolution on protection against harmful products.

The resolution establishes for the first time international procedures and standards for trade in products harmful to health and the environment. Administration apologists would have us believe that by its resolute stand America's national honor was successfully defended against an unprincipled assault by hot-headed radical third-world countries aided and abetted by the Soviet bloc.

But this is a resolution that even our traditional allies in international diplomacy, not to mention the rest of the world community, found acceptable enough to support. Japan, West Germany, and Great Britain - hardly bastions of radicalism - all voted for the resolution.

This is not the first time the Reagan administration has stood isolated in multilateral diplomacy with a position on an issue on which effective international cooperation is clearly needed. In May 1981, the US government was the only country to vote in the World Health Organization against the establishment of an international code of standards for marketing baby food. (Three countries abstained.)

The US refusal earlier this month in Jamaica to sign the Law of the Sea Treaty has been widely publicized (46 other countries did not sign but 117 did). Much less well known is the fact that, alone among the major maritime and industrial nations, the United States refused to join the preparatory commission for the treaty. Other nonsignatory countries are participating because they want to be involved in the implementation of the treaty, and many are expected, sooner or later, to sign it.

The principle that the government has an obligation to protect its citizens and the environment from harmful products is well established. Furthermore, the US has done more than any other country to create some procedures, though limited, to prevent US companies from dumping hazardous products that cannot be sold in the US on unsuspecting foreign countries.

The UN resolution takes a small step toward bringing the rest of the world into conformity with the US position by creating a consolidated international list of drugs, pesticides, and other hazardous products. It also embraces the sensible principle that such products should not be exported without the informed consent of the importing country.

It is clearly in the US national interest - and that of the US business community - to have all countries play by the same rules. But even more direct self-interest is involved through the ''boomerang effect.''

Pesticides banned in the US but freely exported come back to the US embedded in imported foodstuffs. For example, a 1978 Food and Drug Administration study of coffee entering the US showed that 45 percent of the samples tested had pesticide residues illegal by US standards.

Public outrage over the dumping by US manufacturers on third-world countries of 2.4 million baby garments treated with a chemical said to be carcinogenic and banned in the US led President Carter in the waning days of his administration to sign an executive order to strengthen US policy on export of hazardous substances. Thirty-four days later, President Reagan summarily revoked the Carter executive order, branding it as ''excessive regulation.''

No country likes to have products banned or severely restricted in the country of origin dumped on it. Indignation over the Reagan revocation of the Carter executive order was an important factor in pushing through this resolution at the UN. Here is another case of chickens coming home to roost.