THE U.S. Court of Appeals for the District of Columbia has ordered the Department of Labor to begin enforcement immediately of a regulation providing oxygen-generating self-rescue devices for underground coal miners.

The regulation was to have gone into effect Dec. 21, but was postponed for six months by Labor's Mine Safety and Health Administration after coal companies protested that the devices needed more testing.

The decision to postpone, announced in early December by Robert B. Lagather, who was the MSHA administrator, was challenged in appeals court by the Centers for Law and Social Policy, representing coal miners.

One of the center's clients, district 12 of the United Mine Workers of America, yesterday petitioned the MSHA to conduct compliance inspections in 26 underground mines in Illinois. Mines found not to have the required breathing devices could be cited for violations of federal minesafety law.

The Court of Appeals ruling, handed down Tuesday by a three-judge panel, held that the MSHA acted wrongly in its eleventh-hour postponement of the regulation. Proper procedure, the panel said, would call for enforcement of the standard, which coal operators could then challenge through administrative appeal procedures provided for in the safety law.

The new breathing devices, which provide at least a one-hour supply of oxygen, are considered a major advance in protecting miners from asphyxiation and suffocation in underground accidents. They will replace devices that only convert carbon monoxide to carbon dioxide and provide no oxygen.