IN EVERYONE'S LIFE there should be a I little room for light entertainment, (read trash), and with that rationalization firmly in mind, I began two years ago to watch "Dallas." What you might be saying now is nothing compared to what my children said then. Ever ready to ridicule, they promptly labeled America's hit show, "Mother's soap," and each Friday night I had to negotiate an obstacle course of verbal barbs before being able to settle into the world of big oil and tawdry people.

There is, of course, no excuse for watching awful people do awful things to each other on television every Friday night. But the fact that 22 million other Americans are similarly engaged is some comfort. Besides, if "Dallas" doesn't do any good, at least it doesn't do any harm. That's what I thought until last Friday night.

While I cannot imagine viewers taking the perils of J.R., Pam, Sue Ellen or Bobby or Miss Ellie very seriously, the show, like any other, does send subtle messages that can influence viewers in ways they don't even realize. Thus, last Friday night, we had Bobby finally getting a baby for Pam, and what he proceeded to do with the baby was enough to make me sit, as they say, bolt upright on the living room sofa. (For the one reader who is still with me but doesn't follow Dallas, thanks, but it's too late now to explain the plot.) Bobby gives $30,000 to some creep who hands over J.R.'s illegitimate baby. "Wait a minute," Bobby says, (or words to that effect), "I'll get the car seat."

Bobby, having drawn 22 million viewers' attention to the need for putting babies in car seats, then proceeds to put the baby in the most dangerous kind of infant restraint going. Instead of bringing out a sturdy seat designed to protect a child in case of a car accident, Bobby brings forth a white plastic infant seat that is designed for carrying babies or for feeding them. He puts the infant seat down on the passenger's side and places the baby in it. Not until he got home and out of the car, does the viewing audience even get the idea that our hero has at least placed the seat belt across the infant seat to keep it from flying straight out of his red convertible, baby and all.

"Those infant carriers are simply too flimsy," says Peter Kissinger of the National Transportation Safety Board staff. "They're not strong enough to withstand the forces one would encounter in a typical automotive accident. It's quite possible the thing could disintegrate, and you're not going to be better off than with nothing at all because you're going to have these broken pieces of plastic to contend with as well."

Unfortunately, he says, a lot of people do think infant seats are safe. An approved car seat, however, is one whose manufacturer has proved can hold up in an accident and protect the child. "An approved device will have a label on it that says it meets the applicable federal standards," Kissinger says. "That's the most important thing for a buyer to look for."

There has been a lot of attention paid lately to the impact of television on its viewers and some rather weighty charges have been leveled against the medium. To hear some tell it, television is single handedly to blame for the decline in America's morals and the rise in its crime. The one thing people on all sides seem to agree on is this: whether television is generally good or generally bad, it has tremendous influence.

Last Friday night, it suggested to 22 million viewers that it was all right for an adult to put a baby in a plastic infant seat in the front passenger area of a convertible, strap it down with a seat belt and drive on the highway. Nothing happened as a result of what Bobby did; no one criticized him for it, therefore it must be okay. In a nation where 90 percent of the children under 5 years of age ride without seat belts or car seats, and where 850 of them are killed and 57,000 of them are injured in car accidents each year, it is a safe bet that most of the audience was as ignorant about the perilous traveling situation Bobby Ewing was creating for the baby as was Bobby Ewing.

Television never has covered itself with glory in the field of consumer education, but here was an obvious example in which it was needlessly irresponsible. Using the unsafe equipment did nothing to the plot. The producers could just as easily have had Bobby place the baby in a sturdy infant restraint, one designed for traveling, not feeding, that was properly secured in the back seat. In so doing, they could have conveyed a constructive message that might save lives.

No one is expecting television producers to become safety advocates, but at the same time, there is no excuse for them to be advocating safety hazards. The equipment Bobby Ewing used was hazardous; the subtle message was that it was safe. If producers of shows such as "Dallas" have babies and young children featured in scripts, then they ought at least to hire a consultant who can keep them from needlessly misleading viewers about what is safe for children.

What was merely a prop on television could cost lives in the real world.