What with nuclear meltdowns and pieces of space stations falling down around our ears - not to mention friendly ghosts, adventuresome pirates and other cheerful things - it shouldn't surprise anyone to learn that the skull and crossbones, that stalwart old symbol of death, destruction and poison, has lost its punch. Has, in fact, become so benign that it isn't warning anybody about anything.

You thought the Cowardly Lion had problems. Think of the people in the poison-control business.

A few years ago the people at the Pittsburgh poison center, now national headquarters for the National Poison Control Center Network, set out to find what would deter a child from ingesting something poisonous.

(Not surprisngly, children under the age of 5 account for 80 percent of the more than 3 million non-fatal poisonings that occur in this country each year.)

The Pittsburgh folks tested groups of children in day-care centers and found that, of six symbols, most youngsters indicated they would most like to play with bottles marked with the skull and crossbones.

The one marking they didn't think they'd much like was a cartoon abstraction of a frowning face sticking out its tongue. As one child said, "Because he was yukky."

So the face got a name at the same time: Mr. Yuk. Yukky for short.

Sometimes called "feh," or "icky," - or POISON!

But whatever he's called, his message is clear: Do not eat. Do not touch. Beware.

Poison-control centers affiliated with the national network have a number of advantages, including the almost instant ability to draw on the informational resources of all other members.

They also have a lock on Mr. Yuk; they own the copyright and are the sole distributors of his bright green, uncheery face, with its reassuring stick-to-a-bottle backing.

Send a self-addressed, stamped, business-size envelope. The first sheet (of 12 stickers) is free. For more, they ask for a donation of at least 15 cents a sheet.

The Yukky stickers are fine for kids, and they're good for adults too. Especially senior citizens with less than 20-20 vision who are frequently involved in accidental poisonings because they've misread a label or prescription direction. They do seem to be coming in smaller print these days . . .

District and Virginia poison control centers are not associated with the national network, although Virginia is in the process of becoming a member. Because the stickers are imprinted with only local poison control numbers, their effectiveness in nonparticipating areas would be limited to their warning nature.

The Maryland center has other educational aids available, including sets of educational cards of $1 a set, to teach preschoolers about poisons.

Here are the area poison-information numbers:

District: 745-2000

Bethesda: 530-3880

Other parts of Maryland: 1-800-492-2414

Virginia:

Alexandria: 370-9000, ext. 555

Arlington: 558-6161

Fairfax 698-3600

Experts suggest you be prepared with the following information when you call:

What was taken.

How much.

How long ago.

Age and weight of person who took it.

Symptoms.

Any first-aid already performed.

Any previous medical problems.

Your telephone number and zip code.

If you are placed on hold and are disconnected, call back.