Types of Fireworks

Consumer Fireworks " reloadable aerial shells 1.75" or less sold in a box with not more than 12 shells and one launching tube " single-shot aerial tubes " bottle rockets " skyrockets and missiles " ground spinners, pinwheels and helicopters " flares & fountains " roman candles " smoke and novelty items " multi-shot aerial devices, or "cakes" " Firecracker packs (see this link for various brand/label images) " sparklers " snakes and strobes " mines 

Display Fireworks The following devices are for professional use and only available with a ATF license/permit: " any ground salute device with over 50 milligrams of explosive composition " torpedoes (except for railroad signaling use) " multi-tube devices containing over 500 grams of pyrotechnic composition and without 1/2" space between each tube " any multiple tube fountains with over 500 grams of pyrotechnic composition and without 1/2" space between each tube " any reloadable aerial shells over 1.75" diameter " display shells " any single-shot or reloadable aerial shell/mine/comet/tube with over 60 grams of pyrotechnic composition " any Roman candle or rocket with over 20 grams of pyrotechnic composition " any aerial salute with over 130 milligrams of explosive composition

In the United States, the laws governing consumer fireworks vary widely from state to state and even from county to county and municipality to municipality. Many jurisdictions limit sales to seasons and others limit both sales and use to seasons. Fireworks can only be sold to people over the age of 18; it is illegal to sell fireworks to any minor in any state. Five states (Delaware, Massachusetts, New Jersey, New York, and Rhode Island) ban the sale and use of all consumer fireworks including novelties and sparklers by the general public. One state (Arizona) permits residents to purchase and use only novelties. Five states (Illinois, Iowa, Maine, Ohio and Vermont) permit residents to purchase and use only wire or wood stick sparklers and other novelties. Nineteen states (California, Colorado, Connecticut, Florida, Georgia, Kentucky, Idaho, Maryland, Michigan, Minnesota, Nebraska, North Carolina, Oregon, Pennsylvania, Utah, Virginia, Wisconsin, West Virginia, and the District of Columbia) allow residents to purchase and use non-aerial and non-explosive fireworks like novelties, fountains and sparklers. For example: California has very specific requirements for the types of consumer fireworks that can be sold to and used by residents. Even then each city can and often does place restrictions on sale and use. In Minnesota only consumer fireworks that do not explode or fly through the air are now permitted to be sold to and used by residents. In Nebraska the sale and use of all consumer fireworks are prohibited in Omaha, while in Lincoln there is a two day selling period and in other parts of the state all of the permitted types can be sold and used by residents. Nineteen states Alabama, Alaska, Arkansas, Indiana, Kansas, Louisiana, Mississippi, Missouri, Montana, New Hampshire, New Mexico, North Dakota, Oklahoma, South Carolina, South Dakota, Tennessee, Texas, Washington and Wyoming permit the sale of all or most types of consumer fireworks to residents. Many of these states have selling seasons around the 4th of July and/or Christmas and New Year's Eve. Some of these states also allow local laws or regulations to further restrict the types permitted or the selling seasons. For example: Missouri permits all types of consumer fireworks to be sold to residents with two selling seasons; June 20-July 10 and December 20-January 2. South Carolina permits all types of consumer fireworks except small rockets less than ½" in diameter and 3" long to be sold and used by residents year round. Two states (Hawaii and Nevada) allow each county to establish their own regulations. For example, Clark County where Las Vegas is located allows residents to purchase and use only non-explosive and non-aerial consumer fireworks during the 4th of July, while other counties permit all types of consumer fireworks. Many states have stores with all types of consumer fireworks that sell to non-residents with the provision they are to remove the purchased fireworks from that state. This is why there are so many stores selling fireworks in states like Ohio, Florida, Missouri, New Hampshire, Nevada and Wisconsin with all types of consumer fireworks, even though residents are limited or prohibited from buying or using those very same consumer fireworks unless they have the appropriate licenses and/or permits. Many Native American Tribes have consumer fireworks stores on reservation lands that are exempt from state and local authority. These are often near casinos and tobacco outlets that are also exempt from state and local laws.

How Fireworks Work 

Have you ever wondered how fireworks magic works? What is launched into the sky to make these beautiful displays? You have probably seen both sparklers and firecrackers. It turns out that if you understand these two pyrotechnic devices, then you are well on your way to understanding aerial fireworks. The sparkler demonstrates how to get bright, sparkling light from a firework, and the firecracker shows how to create an explosion. Firecrackers have been around for hundreds of years. They consist of either black powder (also known as gunpowder) or flash powder in a tight paper tube with a fuse to light the powder. Black powder, discussed briefly in How Rocket Engines Work, contains charcoal, sulfur and potassium nitrate. A composition used in a firecracker might have aluminum instead of or in addition to charcoal in order to brighten the explosion.  Sparklers are very different from firecrackers. A sparkler burns over a long period of time (up to a minute) and produces extremely bright and showery light. Sparklers are often referred to as "snowball sparklers" because of the ball of sparks that surrounds the burning portion of the sparkler. A sparkler consists of several different compounds: " A fuel " An oxidizer " Iron or steel powder " A binder " potassium nitrate is a very common one. The fuel is charcoal and sulfur, as in black powder. The binder can be sugar or starch. Mixed with water, these chemicals form a slurry that can be coated on a wire (by dipping) or poured into a tube. Once it dries, you have a sparkler. When you light it, the sparkler burns from one end to the other (like a cigarette). The fuel and oxidizer are proportioned, along with the other chemicals, so that the sparkler burns slowly rather than exploding like a firecracker. It is very common for fireworks to contain aluminum, iron, steel, zinc or magnesium dust in order to create bright, shimmering sparks. The metal flakes heat up until they are incandescent and shine brightly or, at a high enough temperature, actually burn. A variety of chemicals can be added to create colors. An aerial firework is normally formed as a shell that consists of four parts: " Container - Usually pasted paper and string formed into a cylinder " Stars - Spheres, cubes or cylinders of a sparkler-like composition " Bursting charge - Firecracker-like charge at the center of the shell " Fuse - Provides a time delay so the shell explodes at the right altitude Located just below the shell is a small cylinder that contains the lifting charge. The shell is launched from a mortar. The mortar might be a short, steel pipe with a lifting charge of black powder that explodes in the pipe to launch the shell. When the lifting charge fires to launch the shell, it lights the shell's fuse. The shell's fuse burns while the shell rises to its correct altitude, and then ignites the bursting charge so it explodes. Simple shells consist of a paper tube filled with stars and black powder. Stars come in all shapes and sizes, but you can imagine a simple star as something like sparkler compound formed into a ball the size of a pea or a dime. The stars are poured into the tube and then surrounded by black powder. When the fuse burns into the shell, it ignites the bursting charge, causing the shell to explode. The explosion ignites the outside of the stars, which begin to burn with bright showers of sparks. Since the explosion throws the stars in all directions, you get the huge sphere of sparkling light that is so familiar at fireworks displays. Multibreak Shells More complicated shells burst in two or three phases. Shells like this are called multibreak shells. They may contain stars of different colors and compositions to create softer or brighter light, more or less sparks, etc. Some shells contain explosives designed to crackle in the sky, or whistles that explode outward with the stars. Multibreak shells may consist of a shell filled with other shells, or they may have multiple sections without using additional shells. The sections of a multibreak shell are ignited by different fuses. The bursting of one section ignites the next. The shells must be assembled in such a way that each section explodes in sequence to produce a distinct separate effect. The explosives that break the sections apart are called break charges. The pattern that an aerial shell paints in the sky depends on the arrangement of star pellets inside the shell. For example, if the pellets are equally spaced in a circle, with black powder inside the circle, you will see an aerial display of smaller star explosions equally spaced in a circle. To create a specific figure in the sky, you create an outline of the figure in star pellets, surround them as a group with a layer of break charge to separate them simultaneously from the rest of the contents of the shell, and place explosive charges inside those pellets to blow them outward into a large figure. Each charge has to be ignited at exactly the right time or the whole thing is spoiled.