THE SENATE Labor and Human Resources Committee has begun an important set of confirmation hearings on the president's choice of a new general counsel to the Equal Employment Opportunity Commission, Jeffrey Zuckerman. Mr. Zuckerman, who is 35 years old, came to the Justice Department from a large New York law firm in the first Reagan term as a specialist in antitrust matters. He moved to the EEOC 16 months ago as chief of staff to Chairman Clarence Thomas. Based on his record in this staff job, civil rights groups and some committee Democrats are questioning his nomination. They fear that as general counsel he would flout what they regard as the law.

The examples they have provided so far are in the field of age discrimination. If an employer has to lay off people, can he lay off older workers first on the ground that they can collect retirement benefits and will not be as badly hurt as their younger brethren? Three appeals courts have read the age law to say no, which has also been the commission's position in the past. Mr. Zuckerman indicated in a memo last year that his inclination would be to reverse that position; he pointed out at a first hearing on his nomination last month that the three appeals court rulings are binding on the commission only in the circuits where issued. Appeals courts and the commission have also held in the past that if a practice has an "adverse impact" on older employees, the burden shifts to the employer to prove the practice is not discriminatory. Mr. Zuckerman's contrary view of the law, he testifed last month, is that it may be enough if the practice is simply "reasonable."

His views on these arcane matters are important because the general counsel is one of the unsung gatekeepers in the federal syste Equal access to jobs is arguably the leading civil rights concern of the 1980's, and the EEOC is where most people who think they have been discriminated against are required to turn first for relief. The general counsel plays a major role in deciding when and how the agency will bring to bear its greatest power in their behalf, the power to sue. He as much as anyone decides who will and won't get help.

The senators should not seek to keep Mr. Zuckerman out of this job because they would rather have someone with different opinions; that is not their function. But they do have a duty to assure themselves that he will not toy with the law. That describes his burden as well, and it is what the confirmation hearings should be about.