Black Powder:
 The term Black Powder was first used in the late 19th century to distinguish prior gunpowder formulations from the new smokeless powders and semi-smokeless powders, by color reference, up to this point the powder was always refered to as gunpowder.

 21st century, the term gunpowder refers broadly to any small arms, firearms, propellant powder.

Powder Keg:
 A powder keg is a barrel of gunpowder. The powder keg was the primary method for storing and transporting large quantities of black powder up until the 1870s.

Explosive:
 Gunpowder is classified as a low explosive because of its relatively slow decomposition rate. Low explosives deflagrate at subsonic speeds. Ignition of the powder packed behind a bullet must generate enough pressure to force it from the muzzle at high speed, but not enough to rupture the gun barrel.

Mixture:
 Gunpowder, also known since the late 19th century as black powder, is a mixture of sulfur, charcoal, and potassium nitrate. Gunpowder can be made just using potassium nitrate and charcoal, but without the sulfur, the powder is not as strong. It burns rapidly, producing a volume of hot gas made up of carbon dioxide, water, and nitrogen, and a solid residue of potassium sulfide. Because of its burning properties and the amount of heat and gas volume that it generates, gunpowder has been widely used as a propellant in firearms and as a pyrotechnic composition in fireworks.

Ingredients:
 Black powder is a granular mixture of a nitrate, typically potassium nitrate (KNO3), which supplies oxygen for the reaction; charcoal, which provides carbon and other fuel for the reaction, simplified as carbon (C); sulfur (S), which, while also serving as a fuel, lowers the temperature required to ignite the mixture, thereby increasing the rate of combustion. Potassium nitrate is the most important ingredient in terms of both bulk and function because the combustion process releases oxygen from the potassium nitrate, promoting the rapid burning of the other ingredients.

Various Mixtures:
 These ratios have varied over the centuries and by country, and can be altered somewhat depending on the purpose of the powder. For instance, power grades of black powder, unsuitable for use in firearms but adequate for blasting rock in quarrying operations, is called blasting powder rather than gunpowder.

Gunpowder:
 Proportions by weight are 75% potassium nitrate, 15% charcoal, and 10% sulfur.

Sizes:
 Potassium nitrate, sulfur, and carbon react together to form nitrogen and carbon dioxide gases and these expanding gases provide the propelling action for projectiles in muzzleloaders.
 Granular size of black powder determines the intended use of the powder. The following sizes are for the specific use in muzzleloaders.
 Fg: This grain size of black powder has the largest grains and normally is used in muzzleloading muskets and small cannons.
 FFg: This grain size of black powder is smaller than Fg powder and is most commonly used in muzzleloading shotguns and larger bored rifles starting at about .45 caliber and up.
 FFFg: This grain size of black powder is smaller than FFg and is used primarily in pistols and muzzleloading small bore rifles .45 caliber and down.
 FFFFg: This grain size of black powder is smaller than FFFg and is used only in flash pans on flintlock ignition systems.

Blasting Powder:
 Proportions by weight are 70% potassium nitrate, 14% charcoal, and 16% sulfur.

Ignition Inhibitor:
 To reduce the likelihood of accidental ignition by static electricity, the granules of modern black powder are typically coated with graphite, which prevents the build-up of electrostatic charge. Anyone handling black powder are well advised to wear cotton clothing as this reduces static electricity as well.

Other Uses:
 In quarrying, high explosives are generally preferred for shattering rock. However, because of its low brisance, black powder causes fewer fractures and results in more usable stone compared to other explosives, making black powder useful for blasting monumental stone such as granite and marble. Black powder is well suited for blank rounds, signal flares, burst charges, and rescue-line launches. Black powder is also used in fireworks for lifting shells, in rockets as fuel, and in certain special effects.

Classification:
 United States Department of Transportation, have classified Gunpowder (black powder) as a Group A: Primary explosive substance for shipment because it ignites so easily. Complete manufactured devices containing black powder are usually classified as Group D: Secondary detonating substance, or black powder, or article containing secondary detonating substance, such as firework, class D model rocket engine, etc., for shipment because they are harder to ignite than loose powder. As explosives, they all fall into the category of Class 1.