WASHINGTON (AP) _ President Reagan on Thursday bragged that he and George Bush have ''weeded out and eliminated wasteful, unnecessary and intrusive'' federal environmental, safety and other regulations costing American consumers tens of billions of dollars.

In his final report on government regulations, Reagan listed reducing regulatory burdens imposed under past presidents, ''cutting red tape and slowing the pace of new regulations'' as one of his proudest achievements.

''This administration understands that American life is burdened by too much regulation and that true regulatory reform must involve regulatory reduction,'' Reagan said in the 603-page report.

Unlike a year ago when the White House report on the same topic never mentioned Bush, Reagan this year shares the credit with his vice president and a task force that Bush chaired for eliminating ''unnecessary regulatory costs.''

''The steady but enormous progress the vice president and I have made over the past 7 1/2 years to improve the way government regulates has been one of our administration's proudest achievements,'' Reagan said.

Officials in charge of the White House Office of Management and Budget responsible for the report quipped that the omission of Bush's name last year ''probably was an oversight.''

David Plocher, an attorney for OMB Watch, a research and advocacy program that tracks the White House budget office's role in federal regulations, said most of the work by the task force that Bush chaired was accomplished between 1981 and 1983.

''It was resurrected in 1987 to give George Bush something else to put on his resume,'' Plocher said, ''but there has been virtually no evidence that the resurrected task force has accomplished anything. He got the title but he actually hasn't done the work.''

Plocher called Bush a ''Gerald Ford Republican who doesn't share the ideological fervor'' toward deregulation that many officials in Reagan's budget office hold.

White House Budget Director James C. Miller III acknowledged that the Bush task force had been relatively inactive until the past year, but said the vice president has been the key player in making the more than 100 agencies that issue and enforce regulations carry out Reagan's policies.

''While OMB carries a great deal of clout,'' Miller said, ''it was really the vice president whose clout mattered in getting things done, getting agencies to turn around and look at regulatory matters in ways they hadn't looked at them before.''

As an example, Miller said Bush has been instrumental in pushing the Food and Drug Administration to encourage the development of so-called ''orphan'' drugs for treating rare diseases.

The orphan drug proposal ordered by Congress is one of 451 listed by the administration as ''significant regulatory actions'' planned by the administration between April of this year and next March 31, or roughly two months after the next president assumes office.

By far, the largest areas of regulatory activity concern environmental and work place matters, with 98 of the proposed actions in the Environmental Protection Agency and 91 in the Labor Department, most of them in the Occupational Safety and Health Administration.

EPA, the Labor Department and the departments of Transportation and Health and Human Services account for about 60 percent of the anticipated regulatory activity this year, the report said.

Of the 451 actions, 87 of 19 percent have congressionally or court-mandated deadlines.

Miller and other OMB officials could not specify how many of the 451 involve reducing regulatory burdens and how many will result in increasing them.

''Some of it is deregulatory in the clear sense, but that is a relatively small part this year,'' said S. Jay Plager, the new administrator of the Office of Information and Regulatory Affairs at OMB.

Nonetheless, OMB officials said in the report that the administration ''has succeeded in eliminating thousands of unnecessary federal regulations and the costs associated with them - ranging in the tens of billions of dollars.''

Plocher said the administration's centralization of regulatory action in the White House budget office has ''led to the gutting of several public services.''

''The American people are paying a price for that, too, but has yet to realize the full extent of it,'' Plocher said. ''Toxic wastes are washing up on beaches and leaking up from landfills, acid rain is destroying forests and the workplace is less safe.''