Stemming from July 4, 1776, Fourth of July symbolizes Independence Day in the United States. Every year, American families gather on this date for afternoon barbecues – engorging themselves with cheeseburgers, hot dogs, pasta salad, casseroles, watermelon and desserts.

But what does Fourth of July have in common with other celebrations in cultures worldwide? – Fireworks. So...just how are those explosive wonders made?

The Science

No surprises here: The conception of the firework was simply derived from chemistry's Combustion Theory.

In order to construct a successful firework, six key ingredients must be present:

• A fuel source.
• An oxidizing agent.
• A reducing agent.
• A regulator.
• A coloring chemical.
• A binding agent.

Each day, Vortex slide gates and diverter valves handle many raw materials used in fireworks production.

Fuel Sources

The most common material used to fuel fireworks is charcoal.

Fuel ignition is a basic scientific concept, but is complex to understand. In short, a firework propels itself from the ground as a result of many chemical reactions.

Step 1. At the base of the firework is an oxidizer. This structure is what provides the firework with a direct path of travel.

Step 2. When the firework is ignited, the fuel source begins to lose electrons as they travel toward atoms in the oxidizer.

Step 3. The electron-charged atoms generate a chemical reaction that reduces the oxidizer. This causes the oxidizer to also reject the atoms, allowing them to pass through it.

Step 4. The atoms and fuel source bond to create a combustible compound.

Step 5. When ignited, the compound liquefies and creates a pressurized vapor. That pressure expels through the back-end of a firework to energize it for lift-off.

Oxidizing Agents

As explained above, an oxidizing agent is necessary to ensure a firework's internal contents can burn and combust. Common oxidizing agents include nitrates, chlorates and perchlorates.

Though the chemistry behind each material is intricate, chlorates are the most effective oxidizing agent in firework manufacturing. The reason being: Chlorates retain the perfect amount of oxygen at the point of explosion, which creates the most impressive combustion.

Alternatively, perchlorates retain even more oxygen, but have improved chemical stability – making them less likely to explode. Nitrates use only one-third of their oxygen potential, resulting in an underwhelming firework explosion.

Reducing Agents

Using the same chemical reaction that allows a hot air balloon to take flight, reducing agents are necessary in fireworks to produce hot gasses, which allow for vertical travel. The most common reducing agents are sulphur and charcoal. When ignited, these materials react with oxygen to create sulphur dioxide and carbon dioxide, respectively. These gasses fuel the firework through its path of travel, prior to explosion.

Regulators

Regulators are often made from various metal powders and are essential to firework safety. As the technical term "regulator" suggests, by adding trace amounts of metal to a firework's internal mix of chemicals, the speed of the explosive reaction can be regulated. In essence, the inclusion of metal creates a slower burn and thus, a delayed explosion.

Regulators are arguably the firework's most important component, as they are the difference between "bombs bursting in air" and "bombs bursting at your feet." 

Coloring Chemicals

It is a little-known fact that, in order to create different firework colors, different chemicals must be added to the firework's "ingredients."

The following chemicals are most commonly used to create each firework color: 

• Red: Strontium and/or Lithium
• Orange: Calcium
• Yellow: Sodium
• Green: Barium
• Blue: Copper
• Purple: Potassium and/or Rubidium
• Gold: Iron, Charcoal and/or Lampback
• White: Titanium, Aluminum, Beryllium and/or Magnesium

Just like paints and dyes, different-colored chemicals can be mixed to create another color, or to create multi-colored fireworks.

To generate the colors, the chemicals reach high temperatures as they burn in the explosion. The high temperatures generate photon (hv) light energy, thus allowing spectators to see color.

DID YOU KNOW? – Blue is the most challenging firework color to achieve. This is because blue color saturation can only be achieved at very high chemical temperatures. Thus, the higher the temperature, the bluer the firework.

Binding Agents

Binding agents serve as the firework's "cabin," housing all of the explosive materials in a confined space so that they can burn and react with one another. Binding agents are often constructed from starchy materials, such as dextrin and paron.

DID YOU KNOW? – Paron is only used to bind red and green fireworks because its properties make those colors more vibrant.

The Biggest Firework of All...

Vortex equipment is used to handle fuel for the largest firework ever built; a piece of art that propels the highest distances known to man – but does not explode.

Did you solve the riddle? It is a space shuttle.

Okay...so our equipment was not used to make a Guinness World Record-breaking explosive, but it is used to handle dry, solid rocket fuel.

Launching spacecrafts to perform research on our universe? That's the greatest show of all!