A FEW DAYS AGO, when Edith Barksdale Sloan left her post as director of the D.C. Office of Consumer Protection to become the newest presidential appointee to the Consumer Product Safety Commission, we noted that her absence would be keenly felt. Little did we know just how keenly - until we discovered that Mayor Walter Washington had appointed Bettie Robinson, formerly general counsel for the consumer office, to be acting director. We have nothing personal against Mrs. Robinson. But her appointment does say something about the mayor's judgement in these matters. At the time of her promotion Mrs. Robinson actually had dismissal proceedings pending against her.

The nomination becomes even more curious when you consider that both Mrs. Sloan and the citizens' advisory committee that is supposed to oversee the Office of Consumer Protection specifically recommended against it. Nevertheless, the mayor went right ahead, three days after Mrs. Sloan's departure. Before she left, Mrs. Sloan filed a complaint against Mrs. Robinson with George Harrod, director of the D.C. Personnel Office, and Julian Dugas, city administrator, citing an unsatisfactory work record and recommending transferral to another office. That wasn't the first time the matter had come up. Late last year, Mrs. Sloan had several discussions with personnel officials about Mrs. Robinson's failure to keep up with her work. The mayor contends he didn't know a thing about the dismissal request before he made his appointment. Mr. Dugas, a confidant of the mayor, says he isn't sure things would have been handled differently in any case. And while that is an astonishing thought, it has a certain plausibility in light of reports that Bill Lucy, chairman of the Democratic Central Committee and longtime friend and supporter of the mayor, intervened in behalf of Mrs. Robinson.

It's not as if no better candidates are available for the job of acting director. For example, DOrothy Kennison, a senior program analyst in that office, is one person both Mrs. Sloan and the advisory committee thought qualified. In our view, the mayor should quickly find another acting director - at least until the dismissal procedings against Mrs. Robinson have been resolved. Charges of failure to do your job are odd grounds for promotion to a more demanding and responsible position.