U.S. workers in hazardous jobs -- such as those who are FBI agents, firefighters, air traffic controllers and, uh, those serving in Congress--will probably be exempted from some of the drastic retirement changes the Reagan administration is proposing for most other government workers.

Within the next few weeks the White House will send Congress legislation that would overhaul the federal retirement program. It now permits employes to retire at age 55 (with 30 years service) on 56 percent of salary, with pensions fully indexed to inflation.

If Congress goes along with the plan, government employes retiring in the future would take an annuity cut of 5 percent for each year they were under age 65. Workers could still retire at 55, but their annuity would be slashed in half. Those penalties, however, would not be applied to law enforcement personnel, firefighters, air controllers or legislators, who are all under a retirement system that does not penalize workers for early retirement.

The Reagan plan would require civil servants, who now contribute 7 percent of their salaries to the federal pension fund, to kick in 9 percent next year and 11 percent starting in 1985. In addition, annuities now calculated on length of service and the employes' highest average salary over a three-year period would be gradually changed (in three years) to a highest-average-in-five formula.

Workers who are 55 (or older) at the time of enactment--assuming that Congress clears the plan--would be covered under the current benefit system. In other words, an employe 55 or older at enactment could still retire in future at 55 with 30 years (or at 60 with 20 years, or 62 with five years) and have benefits calculated under the present system.

Although the proposal is still in the draft stage, administration officials say there is little chance it will mean any early retirement penalty for present or future employes under the special retirement programs.

Most of those workers in high-risk, high-stress jobs (except members of Congress) are required by law to retire at age 55. And they can retire at 50 with 20 years service. All of the special category workers contribute 7 1/2 percent of salary to the retirement fund. Benefits are calculated using a more generous formula to make up for enforced early retirement. There are currently about 18,000 persons retired under the special retirement system, as well as nearly 400 retired members of Congress.

The congressional retirement system is based on the civil service retirement program, although members contribute 8 percent of salary to the retirement fund. Staffers may participate in that program, or the regular civil service retirement plan.

Senate and House members can retire voluntarily at age 50 after serving in nine sessions (about 18 years) or with less service if they are older. Figuring congressional annuities is difficult. But the formula is such that none qualify as paupers based on their pensions.

Members retired involuntarily (voters get a chance to retire them every two or six years) can also get full benefits earned under the system after nine terms in the House or three in the Senate.

One aspect of the Reagan retirement plan, however, would hurt those employes who are permitted to retire at 50, or who are forced out at 55. That is the proposal to limit annual cost-of-living adjustments for retirees who are under age 62 to half the percentage amount that goes to over-62 retirees.