My Page of Chemical Information
Aluminium, Al -- Fuel
This is used in many compositions to produce bright white sparks or a
a bright white flame. There are many grades of aluminium available
for different spark effects. Most pyrotechnic compositions that involve
sparks use aluminium, e.g. sparklers, waterfalls etc.
Ammonium Nitrate, NH4NO3 -- Oxidizer
This is used very infrequently in pyrotechnics due to its hygroscopic
nature and the fact that it decomposes even at relatively low
temperatures. Even when dry, it reacts with Al, Zn, Pb, Sb, Bi, Ni, Cu,
Ag and Cd. In the presence of moisture it reacts with Fe. It reacts with
Cu to form a brissant and sensitive compound. It is best not to use any
bronze or brass tools when working with ammonium nitrate.
Ammonium perchlorate, NH4ClO4 -- Oxidizer
Used as an oxidiser in solid rocket fuels, most notably the solid booster
rockets for the Space Shuttle. Using it in a composition improves the
production of rich blues and reds in the flames. As with any ammonium
salt, it should not be mixed with chlorates due to the possible formation
of ammonium chlorate, a powerful and unstable explosive.
Anthracene, C14H10 -- Smoke Ingredient
Used in combination with potassium perchlorate to produce black smokes.
Antimony, Sb -- Fuel
The metal is commonly used in the trade as 200-300 mesh powder. It is
mainly used with potassium nitrate and sulphur, to produce white fires.
It is also responsible in part for the glitter effect seen in some
fireworks.
Antimony trisulphide, SbS3 -- Fuel
This is used to sharpen the reports of pyrotechnic noisemakers, e.g.
salutes. It is toxic and quite messy.
Barium salts -- Colouring Agents
Used to colour fires green. several are used:
Barium carbonate, BaCO3 -- Colouring Agent, Stabilizer
As well as being a green flame-colourer, barium carbonate acts as a
neutralizer to keep potentially dangerous acid levels down in pyrotechnic
compositions.
Barium chlorate, Ba(ClO3)2.H2O -- Colouring Agent, Oxidiser
Used when deep green colours are needed. It is one of the more sensitive
chemicals which are still used, best to avoid if possible, but if used it
should be in combination with chemicals which will reduce its sensitivity.
Barium nitrate, Ba(NO3)2 -- Colouring Agent/Enhancer, Oxidiser
Not very strong green effect. Used with aluminium powder to produce
silver effects. Below 1000C aluminium burns silvery-gold, characteristic
of aluminium-gunpowder compositions. Above 1000C it burns silver, and may
be achieved using barium nitrate. Boric acid should always be used in
compositions containing barium nitrate and aluminium.
Barium oxalate, BaC2O4 -- Colouring Agent
Sometimes used, generally in specialised items with magnesium.
Boric acid, H3BO3 -- Stabilizer
This is a weak acid, often included in mixtures that are sensitive to
basic conditions, notably those containing aluminium.
Calcium carbonate, CaCO3 -- Stabilizer
Used as a neutralizer in mixtures that are sensitive to both acids and
bases, for example chlorate/aluminium flashpowder.
Calcium oxalate, CaC2O4 -- Colour Enhancer
Used to add depth to colours produced by other metal salts.
Carbon black/Lampblack, C -- Fuel
A very fine form of carbon made by incompletely burning hydrocarbon fuels.
Commonly used in gerbs to produce bright orange sparks.
Charcoal, C -- Fuel
Probably the most common fuel in firework manufacture, it is not pure
carbon and may contain in excess of 10% hydrocarbons. Indeed, the purer
carbon charcoals (e.g. activated charcoal) do not necessarily give better
results, and are very often worse than less pure grades. It is included
in the vast majority of pyrotechnic compositions in various mesh sizes
and grades, or as a component of black gunpowder.
Clay
This is an important material for making fireworks, not as a reagent but
to perform various practical applications such as blocking or constricting
the ends of tubes for crackers or rocket nozzles, or coating lead shot
prior to the application of star composition when making rolled stars.
Copper and copper compounds -- Colouring Agents
Used to add both green and blue colours to flames:
Copper metal, Cu -- Colouring Agent
Both the bronze and electrolytic forms are occasionally used, but easier
methods are available for the same effect.
Copper acetoarsenate, C4H6As6Cu4O16 -- Colouring Agent
Commonly called Paris Green, this chemical is toxic but used to produce
some of the best blue colours in combination with potassium perchlorate.
Copper carbonate, CuCO3 -- Colouring Agent
This is the best copper compound for use with ammonium perchlorate for
production of blue colours. Also used in other blue compositions.
Copper (I) chloride, CuCl -- Colouring Agent
Cuprous chloride is probably the best copper compound for creating blue
and turquoise flames, and it can be used with a variety of oxidizers.
It is non-hygroscopic and insoluble in water, but it is oxidised slowly
in air.
Copper oxides, CuO/Cu2O -- Colouring Agent
Used for many years for blues, but needed mercury chloride to intensify
colours. Seldom used.
Copper oxychloride -- Colouring Agent
Occasionally used in cheap blue compositions.
Cryolite, Na3AlF6 -- Colouring Agent
Also known as Greenland spar, this is an insoluble sodium salt. Sodium
salts are used to produce yellow colours, but as sodium salts generally
absorb water this tends to be a problem. By using cryolite this problem
is surmounted.
Dextrin -- Binder
Dextrin is a type of starch that is added to many firework mixtures to
hold the composition together. It is the most commonly used binder in
pyrotechnics.
Gallic acid (3,4,5-trihydroxybenzoic acid)
This is used in some formulas for whistling fireworks. Whistle mixes
containing gallic acid are generally the most sensitive of the whistling
fireworks, with high sensitivity to both friction and impact when used
with chlorates, but cannot be used with perchlorates either. There are
safer alternatives for whistle compositions.
Gum arabic (Gum Acacia) -- Binder
An example of the various wood-resin-based adhesives used to bind firework
compositions. Others used include Red Gum and Gum Copal.
Gunpowder
Black powder is the mainstay of pyrotechnics. At a basic level it is
a mixture of potassium nitrate, charcoal and sulphur. However, simply
mixing these ingredients together will not produce proper black powder.
It merely produces a much milder version, which itself is used
extensively in pyrotechnics, and is commonly called meal powder.
True black powder takes advantage of the extreme solubility of potassium
nitrate by mixing the very fine milled ingredients into a dough with
water, then using strong compression to force the water out of the
mixture, so that tiny crystals of potassium nitrate form in and around
the particles of the other ingredients. This produces a product that
is far fiercer than the simple meal powder.
Hexachlorobenzene, C6Cl6 -- Colour Enhancer
Used as a chlorine donor in coloured compositions that require one.
Rarely used, with PVC, Saran and Parlon being preferred.
Hexachloroethane, C2Cl6 -- Smoke Ingredient
The basic ingredient in many military smoke formulas. Not often used
with inorganic smoke mixtures, except those containing zinc.
Iron, Fe -- Fuel
The metal filings are used mainly in gerbs to produce sparks. Iron will
not keep well in firework compositions, and so it is generally pre-coated
with an oil/grease. One simple method is to add 1 gram of linseed oil to
16 grams of iron filings, mix, and boil off the excess oil.
Linseed oil -- Stabilizer
Used to coat metal powders in order to prevent them from oxidation, both
prior to use and in the firework composition. Polyesters are used in
commercial fireworks, but linseed oil remains an accessible option to the
amateur.
Lithium carbonate, Li2CO3 -- Colouring Agent
Used to colour fires red. It has no advantage over strontium salts for
the same purpose.
Magnesium, Mg -- Fuel
Used to produce brilliant white fires. Should be coated with linseed oil/
polyester resin if contained in a composition which is not to be used
immediately, as it may react with other components of the mixture. The
coarser magnesium turnings are sometimes used in fountains to produce
crackling sparks. Magnesium-aluminium alloys give similar effects, and
are rather more stable in compositions.
Parlon -- Colour Enhancer, Binder
Parlon is a chlorine donor, and a key ingredient in many coloured stars.
It is a chlorinated isoprene rubber, chlorine content 66%. It interferes
with burning less than PVC or saran, and can be used as a binder. It
is soluble in methyl ethyl ketone (MEK) and partially in acetone.
Compositions made with parlon and acetone or MEK are nearly waterproof.
Phosphorus, P -- Fuel
Phosphorus is rarely used in pyrotechnics today, except for a few
specialized applications. It was used commonly many years ago, but as the
hazards associated with its use became known it dropped out of use.
Phosphorus comes in several forms, of which the red and the white/yellow
varieties were used. Red phosphorus (used in the strikers on the side of
matchboxes) is the more stable form, while white phosphorus (used by the
military in incendiary devices) ignites spontaneously in air, and must
therefore be stored under water or otherwise protected from the
atmosphere. Both forms are toxic.
Polyvinylchloride (PVC) -- Colour Enhancer, Binder
PVC is a commonly used chlorine donor. It is not as good as Parlon for
this purpose, but is cheaper and more readily available. PVC is soluble
in tetrahydrofuran (THF) but almost all other solvents are useless.
Methyl ethyl ketone (MEK) will plasticise PVC to some extent, however.
Potassium benzoate, C6H5CO2K -- Fuel
Used in whistling fireworks, in combination with potassium perchlorate.
It must be very dry for this purpose, and should be less than 120 mesh.
Potassium chlorate, KClO3 -- Oxidizer
Originally used very commonly in pyrotechnics, potassium chlorate has
gradually been phased out due to its sensitivity, in favor of potassium
perchlorate. Mixtures containing potassium chlorate and ammonium salts,
phosphorus or anything acidic are particularly dangerous. For this reason
mixtures containing potassium chlorate and sulphur are to be avoided,
as sulphur (especially the common "flowers" of sulphur) may contain
residual amounts of acid that can sensitize the mixture. In general,
potassium chlorate should be avoided unless absolutely necessary.
Chlorates have probably caused more accidents in the industry than all
other classes of oxidisers together. The reason lies in their sensitivity
to acids and their low decomposition temperature. When mixed with an
easily ignitable fuel, such as sugar or sulfur, chlorates will ignite
from a fingernail striking a wire screen. Moreover, sulfur is often
acidic, a fact that has lead to spontaneous ignition of sulfur-chlorate
compositions. If you intend to use chlorates, pay extra attention to
safety.
Potassium nitrate, KNO3 -- Oxidizer
A very common oxidising agent in pyrotechnics, potassium nitrate is one
of the chemicals you should never be without. From its essential use
in gunpowder to general applications in most fireworks, you will find
potassium nitrate used wherever a relatively mild oxidiser is required.
In fireworks it should pass 120 mesh, but can be used at 60 mesh. The
fine powder should be used as soon as possible after grinding or
milling as it will soon cake and have to be re-ground.
Potassium perchlorate, KClO4 -- Oxidizer
More expensive than potassium chlorate, but a better oxidising agent
and far safer. In almost all mixtures that previously required the
chlorate, safety factors have led to its replacement with potassium
perchlorate. It should be used in place of the chlorate wherever possible.
Potassium picrate
This is a shock sensitive compound that is used in some whistle formulas.
While safer than gallic acid formulas in this respect, care should be
taken to keep it away from other metals such as lead, because some
other metallic picrates are extremely sensitive.
Saran -- Colour Enhancer, Binder
Saran is another plastic chlorine donor. It is most commonly encountered
in the form of the cling wrap used to protect foodstuffs. It is slightly
soluble in tetrahydrofuran (THF) and will be plasticised by methyl ethyl
ketone (MEK).
Shellac -- Binder
Shellac is an organic rosin commonly used as a binder where a water-
soluble binder would be inappropriate. It can be bought at hardware
stores in the form of lustrous orange flakes, which can be dissolved
in boiling ethanol.
Sodium salts -- Colouring Agents
Sodium salts are sometimes used in place of the corresponding potassium
salts, but this is uncommon due to their hygroscopic nature. They rapidly
absorb water from the air, which can ruin a pyrotechnic composition.
In particularly dry environments they can be used without too much
trouble, and are therefore used in places like Egypt due to the relative
cheapness of some of the salts with respect to the potassium ones. Sodium
salts are also used as colourising agents, producing a characteristic
orange flame.
Strontium salts -- Colouring Agents
Used to colour flames a brilliant red:
Strontium carbonate, SrCO3 -- Colouring Agent, Retardant
Used often for producing red colours, and as a fire retardant in
gunpowder mixtures.
Strontium oxalate, SrC2O4 -- Colouring Agent, Retardant, Stabilizer
As for strontium carbonate, generally, but suffers from greater water
content.
Strontium nitrate, Sr(NO3)2 -- Colouring Agent, Oxidiser
This is the most commonly used strontium salt, because it provides the
most superb red colour available. Best results will be acheived if the
strontium nitrate is anhydrous.
Sulphur, S -- Fuel
Another basic fuel in pyrotechnics, sulphur is used in many pyrotechnic
formulas across the range of fireworks, most obviously in black powder.
It is recommended to avoid the common "flowers" of sulphur, as they
contain residual acid. If they cannot be avoided, a small amount of a
neutralizer such as calcium carbonate should be added if acid is likely
to present a problem.
Titanium, Ti -- Fuel
The coarse powder is safer than aluminium or magnesium for producing
sparks, and gives rise to beautiful, long, forked blue/white sparks.
Fantastic for use in any spark composition, especially gerbs.
Petroleum jelly (Vaseline) -- Stabilizer
Very occasionally used to protect metal powders e.g. iron by coating them
with a thin film of petroleum jelly.
Zinc, Zn -- Fuel, Smoke Ingredient
Zinc metal is used in what are known as zinc spreader stars, which
produce a very nice effect that looks like a green glowing cloud. Also
used in several smoke formulas, due to the thick clouds of zinc oxide
that can be produced.
SPECIAL CAVEATS
---------------
AVOID:
Mixing chlorates with: acidic ingredients
sulphur or sulphides
ammonium salts
phosphorus
pitch or asphalt
gum arabic solution.
Mixing picric acid with: lead or lead compounds
almost any other metal.
Mixing ammonium nitrate with metals especially copper.
Mixing nitrates with aluminium WITHOUT boric acid.