Tomorrow is the Fourth of July. You're probably feeling pretty excited about it by now. You may be looking forward to going to a picnic. You may have plans to march in a parade. Or your family may be getting ready to go down to the Mall to watch the fireworks at the Washington Monument.

Fireworks are a traditional part of the Independence Day celebration. We use them as a symbol to celebrate our freedom in the United States. Fireworks have been around ever since the Chinese invented them about 2,000 years ago. They believed that the explosions chased away evil spirits. Around the world, fireworks are an important part of various holidays. The Chinese still set off fireworks to celebrate the New Year. In Mexico, fireworks light up Easter week. In Colorado, fireworks light up the sky around Pike's Peak in the Rocky Mountains every New Year's Eve. Climbers set the charges off at midnight. The explosions can be seen for miles around.

Fireworks are certainly beautiful and exciting. But they also can be very dangerous. Every year, accidents involving fireworks keep emergency room doctors and nurses busy on the Fourth of July. In 1983, there were more than 8,000 such injuries treated in emergency rooms around the country. More than half of the people hurt were younger than 15 years old.

Many adult males also were hurt by fireworks, however. So tell your father to be especially careful if he is planning to put on a fireworks display in your backyard tomorrow night.

Since 1976, the U.S. government has enforced strict rules about the sale of fireworks. The Consumer Product Safety Commission established the rules. They ban any firecracker containing more than 50 milligrams of explosives. That's about one-eighth of a teaspoon. The rules ban devices called Class B fireworks like cherry bombs. Class C fireworks -- which may be sold legally in some states -- include fountains, Roman candles, sparklers and smoke devices like snakes. Class C fireworks must have fuses that burn for at least three seconds. They must be designed so that their bottoms and sides do not blow out when the device goes off.

Class C fireworks are the kind you can buy in the District of Columbia. They have to be inspected by the D.C. Fire Department's fire prevention division before they may be sold. In Maryland, only sparklers are allowed. Virginia allows some Class C fireworks.

Even though cherry bombs and firecrackers are illegal, some people make and sell them. People caught with illegal fireworkers have to pay fines. They may even have to go to jail. Using fireworks illegally is no joke.

There's a good reason for all the concern about fireworks safety. Injuries involving fireworks are serious. The eyes are hurt most frequently, followed by hands and fingers. More than half of these injuries are burns. But some people lose fingers when fireworks explode in their hands. Others are blinded. Some have even been killed.

Some medical researchers think that many more people get hurt every year than the reports from hospitals show. Many people treat their own injuries and don't tell their doctors about them. In an article in Pediatrics, a magazine read by many children's doctors, researchers from the University of New Mexico and the University of Tennessee estimate that only a little more than half of the fireworks-related injuries get reported. They think that as many as 21,000 people may have been hurt in 1983. And they said that the rate of injuries is much higher in places that allow Class C fireworks -- like the District of Columbia.

Every year at this time, fireworks stands pop up all over the city. It's tempting to try their products out. But remember that misuse of fireworks is serious. If you're going to use fireworks, ask an adult to be in charge -- and tell them to be very careful. Ask them to read the tips listed below. Remind them that the emergency room is no place to spend your Fourth of July. Tips for Parents

The following advice for a safe Fourth come from the American Academy of Pediatrics and the Consumer Product Safety Commission:

* Do not allow your children to play with fireworks. They are not toys. Even sparklers, considered by some to be the ideal, safe firework for children, burns at a very high temperature and can easily ignite clothing. They should be used only with parental supervision.

* Supervise the purchase and use of all fireworks. Avoid mail-order fireworks kits.

* Before using fireworks, read and follow warning labels.

* Light one firework at a time.

* Never carry fireworks in your pocket.

* Never throw fireworks at someone else.

* Light fireworks outdoors in a clear area away from houses, people and flammable materials. Keep a bucket of water nearby for emergencies and for dousing fireworks that do not go off.

* Do not try to relight or handle malfunctioning fireworks. Soak with water and throw away.

* Never ignite fireworks in a container, especially a glass or metal one.