THE POLITICS OF SAFETY HAS A LIFE OF ITS OWN

When President Reagan sets his re-election campaign in full gear, he is likely to boast of success in slashing Federal regulations for once-sheltered industries such as the banking business and the airlines.

But Mr. Reagan's record in ''getting government off the backs of the people,'' as he puts it, has been mixed. When it comes to rules that touch on health, safety or the environment, the Administration has found deregulation to be much easier said than done.

A case in point is the decision last week by Transportation Secretary Elizabeth H. Dole requiring air bags or automatic seat belts on all new passenger automobiles sold in the United States in five years. (Later in the week, New York became the first state to enact a law requiring motorists in the front seats to wear seat belts, and all children under the age of 10 to wear belts or sit in safety seats.) The air bag decision was one the Administration wanted to avoid, some say, because these so-called passive restraints represent an especially intrusive instance of government protecting people from themselves. ''Something like this makes me think, for this we elected Ronald Reagan?'' said Walter Olson, associate editor of Regulation, a magazine published by the American Enterprise Institute, a conservative policy research organization. ''This is an issue that sticks out like a sore thumb, because there's an element of people being protected against a hazard they knew they were facing. It's a pure form of paternalism.'' Democrats and some Republicans have long disagreed with that view. From air bags to drugs to motorcycle helmets, Presidents and Congress have held that the law must sometimes protect people against themselves. Steven Kelman, associate director of public policy at the Kennedy School of Government, says an abhorrence of this protective role has been a touchstone of the Reagan Presidency. ''Left to their own devices,'' Mr. Kelman said, ''a lot of people in the Reagan Administration would have urged the virtual elimination of all safety and health regulations. But the level of public commitment to these areas is strong enough to have so far restrained the ideologues.''

Many authorities now say that political realities have tempered the Administration's deregulatory zeal. An example of the mellowing process is the Republican Party platform's call for canceling the 55 mile-per-hour national speed limit. Richard Nixon signed the Emergency Conservation Act to set that fuel-saving standard in 1974, when the country was beginning to feel the effects of the Arab oil embargo. Federal officials later found that it also saved lives.