Shock Sensitive Chemicals
Acetylene (HCCH)

CAS number 74-86-2

DG cat. 2.3 Dissolved gas

The gas mixes well with air, explosive mixtures are easily formed.

Acetylene is an extremely flammable gas. To avoid flashback, a flash arrestor (a
back flow preventive device) should be connected in-line on the output side of
the pressure regulator.

Acetylene supplied is dissolved in acetone, thus the cylinder must be stored in an
upright position to prevent acetone entering the burner.

The substance may polymerize due to heating. The substance decomposes on
heating and increasing pressure, causing fire and explosion hazard. The
substance is a strong reducing agent and reacts violently with oxidants and with
fluorine or chlorine under influence of light, causing fire and explosion hazard.
Reacts with copper, silver, and mercury or their salts, forming shock sensitive
compounds (acetylides).

Piping material for this gas must not contain over 63% of copper.
Acetylides of Heavy Metals (HCC- M+)

Shock sensitive compounds are formed with silver nitrate and copper salts. The
substance decomposes violently on contact with moisture and water producing
highly flammable and explosive acetylene gas, causing fire and explosion
hazard. Reacts with chlorine, bromine, iodine, hydrogen chloride, lead, fluoride,
magnesium, sodium peroxide and sulfur, causing fire and explosion hazard.
Mixtures with Iron (III) chloride, Iron (II) oxide and Tin (II) chloride ignite easily
and burn fiercely.

Reacts violently with fire extinguishing agents such as water, producing explosive
gas.
Ammonium Nitrate (NH4NO3)

CAS number 6484-52-5

DG cat. 5.1 Oxidizing substances

Heating may cause violent combustion or explosion. The substance
decomposes on heating or on burning producing toxic fumes (nitrogen oxides).
The substance is a strong oxidant and reacts with combustible and reducing
materials.

Become shock sensitive when mixed with organic materials.

Aluminum, antimony, bismuth, cadmium, chromium, cobalt, copper, iron, lead,
magnesium, manganese, nickel, tin, and zinc etc reacted violently or explosively
with fused ammonium nitrate below 200oC.
Ammonium Perchlorate (NH4ClO4)

CAS number 7790-98-9

DG cat. 5.1 Oxidizing substances

Contact with combustible materials, flammable materials, or powdered metals
can cause fire or explosion.

The powdered oxidant functions as an explosive when mixed with finely divided
metals, organic materials or sulfur, which increase the shock sensitivity up to that
of picric acid.
Ammonium Picrate (NH4)O-C6H2(NO2)3

CAS number 131-74-8

Decomposes on melting and explodes at 423oC.

The presence of traces metallic picrates (arising from metal contact) increases
heat sensitivity.
Azides of Heavy Metals

Risk of fire and explosion on contact with acids and many metals (Lead, Brass,
Copper, Mercury and Silver)

May explode on heating above melting point, especially on rapid heating, causing
fire and explosion hazard. The solution in water is a weak base. Reacts with
copper, lead, silver, mercury and carbon disulfide to form particularly shock
sensitive compounds. Reacts with acids, forming toxic and explosive hydrogen
azide.

Metal azide is reported to react with dichloromethane (CH2Cl2) in the presence of
DMSO to form explosive products.
Calcium Nitrate Ca(NO3)2

CAS number 39368-85-9

Can cause explosions in contact with combustible dusts or vapors; occasionally
explosive by shock or friction. Sensitive to mechanical impact.

Unstable. Exposure to heat may result in build-up of dangerous pressures. A
strong oxidizer, reacts violently upon contact with many organic substances,
particularly textile and paper.

Mixtures of the nitrate with organic materials may be explosive.
Chlorate (ClO4-)

The substance is a strong oxidant and reacts violently with combustible and
reducing materials, causing fire and explosion hazard. Reacts with strong acids
giving off carbon dioxide. Reacts with organic contaminants to form shock
sensitive mixture.

Metal chlorates in contact with strong acids liberate explosive chlorine dioxide
gas.

Risk of fire and explosion on contact with flames, sparks and organic materials
(such as clothing, leather and paper) or other incompatible materials.
Dinitrotoluene (NO2)2C6H3CH3

CAS number 25321-14-6

DG cat. 6.1 Toxic Substances

Dust explosion possible if in powder or granular form, mixed with air.

May explode on heating. The substance decomposes on heating producing toxic
and corrosive fumes including nitrogen oxides even in absence of air. A
maximum handling temperature of 150oC was recommended. Reacts with strong
bases, oxidants and reducing agents.
Dinitrophenol (NO2)2C6H3OH

CAS number 25550-58-7

DG cat. 4.1 Readily Combustible Substances (>15% water)

May explosively decompose on shock, friction, or concussion. May explode on
heating. Shock sensitive compounds are formed with alkalis, ammonia and most
metals.

It decomposes on heating producing toxic gases including nitrogen oxides.
Ethylene Oxide

CAS number 75-21-8

DG cat. 2.2 Liquefied Gas

Gas / Air mixture are explosive. Risk of fire and explosion as a result of violent
decomposition when heated.

The gas is heavier than air and may travel along the ground; distant ignition
possible.

The substance may polymerize due to heating, under the influence of acids,
bases, metal chlorides and metal oxides with fire or explosion hazard. The
substance decomposes on heating above 500oC, causing fire and explosion
hazard. Metal fittings containing silver, copper, mercury, or magnesium should
not be used since they may react with impurities in the gas to form explosive
compounds.
Formic Acid (HCOOH)

CAS number 64-18-6

Pure formic acid slowly decomposes to release carbon monoxide and may
pressurize containers. Extreme care needed in opening containers of unknown
age.

Use only containers as originally supplied by manufacturer which have vent on
caps.
Fulminating Gold

Prepared by gold chloride and aqueous ammonia, the explosive precipitate is
largely (ClAuNH2)2NH, but on washing with ammonia hydrolysis to the more
explosive
(OHAuNH2)2NH.
Fulminating Silver

Fulminating silver is largely silver nitride (AgN3)

Fulminating silver is the most violently explosive compound among the nitrogen
derivatives of the noble metals. Formed from action of ammonia on silver oxide,
or on addition of potassium hydroxide to an ammoniacal solution of a silver salt.

There is evidence that Tollens reagent (use in organic laboratory to test
aldehyde, also called Silver Mirror Test) can, in reasonably short time, result in
the formation of silver fulminate.

It is black power, which explodes violently in the liquid in which it is formed if the
slightly stirring is used.
Fulminate of Mercury

Readily formed by interaction of mercury (II) nitrate, nitric acid and ethanol.

It may be initiated when dry by flame, heat, impact, friction or intense radiation.

Contact with sulfuric acid causes explosion.
Metal Fulminate (MCN->O)

The metal fulminates are powerful explosive. Of several salts examined those of
cadmium, copper and silver were more powerful detonators than mercury
fulminate, while thallium fulminate was much more sensitive to heating and
impact. Formally related salts are also explosive. Sodium, potassium, rubidium
and cesium fulminates are all easily detonated by feeble friction or heat. They all
form double salts with mercury (II) fulminate which also explode easily, that of the
rubidium salt at 45oC.
Germanium (Ge)

CAS number 7440-56-4

The powdered metal ignites in chlorine, and lumps will ignite on heating in
chlorine or bromine.

The powdered metal reacts violently with nitric acid, and mixture with potassium
chlorate or nitrate explode on heating.

Reacts slowly with water or moisture and liberate explosive hydrogen gas
Hexanitrodiphenylamine C12H5N7O12

CAS number 131-73-7

Powder ignites and burns when heated. Material is shock sensitive and
potentially explosive.

Material can decompose above 251oC.
Hydrazine (H2N-NH2)

CAS number 302-01-2

DG cat. 6.1 Toxic Substances

Stable under ordinary conditions of use and storage. Unstable above 160oC.

Incompatible with oxidizing agents.

Dangerous explosion hazard when dry. Sensitive to mechanical impact.
Sensitive to static charge.
Hydrazoic Acid (HN3)

CAS number 7782-79-8

Hydrogen azide is quite safe in the dilute solution, but is violently explosive and
of variable sensitively in the concentrated (17 - 50%) or pure states.

The solid acid (- 80oC) is also very unstable.

It is necessary to prevent formation of explosive heavy metal azides from
unsuspected contact of hydrogen azide with heavy metals.
Lead Azide Pb(N3)2

Lead azide, on prolonged contact with copper, zinc or their alloys, forms trace of
the extremely sensitive copper or zinc azides which may initiate detonation of the
whole mass of azide.
Lead Styphnate Pb2+ C6H(NO3)2O22
CAS number 15245-44-0

Explosive at temperature above 65.5oC with mechanical shock or impact,
electrical (static) discharge, friction. Extremely hazards when dry.

Store in cool, dry well-vent place away from all sources of ignition. Do not store
at temperature above 65.5oC. Do not subject to mechanical shock.

2-years shelf life limitation.
Nitrate (NO3-)

Nitrate have combustion-supporting properties.

Mixtures of the nitrate with organic solvents, after the solvent has evaporated, the
remaining solid may be with explosive properties.
Nitric Acid (HNO3)

CAS number 7697-37-2

Nitric acid and organic is very unstable and may explode in a sealed container,
this involving formation of unstable fulminic acid (HC
Nitrogen Triiodide (NI3)

Ammonia solutions react with iodide to produce highly explosive addition
compounds of nitrogen triiodide and ammonia.

It is extremely sensitive when dry.

Unstable detonator capable of initiation by minimal amounts of any form of
energy (light, heat, sound, mechanical vibration), even at sub-zero temperatures,
and occasionally even with moisture present.

It explodes possibly owing to heat-initiation on contact with virtually any
concentrated acid, with chlorine or bromine, ozone or hydrogen peroxide
solution.
Nitrogen trichloride (NCl3)

CAS number 10025-85-1

Reaction of ammonium compounds with chlorine may form explosive chlorinenitrogen compounds.

The solid frozen under vacuum in liquid nitrogen explodes on thawing, and the
liquid explodes on heating to 60 to 95oC.

Exposure to impact or light will cause detonation.

A wide variety of solids, liquids and gases will initiate the violent and often
explosive decomposition of nitrogen trichloride. These include concentrated
ammonia, arsenic, hydrogen sulfide, nitrogen oxide, organics, potassium
hydroxide solution or selenium. All four hydrohalide acids (HF, HCl, HBr and HI)
will also initiate explosion of the trichloride.
Nitroglycerin HC(NO3)3

CAS number 55-63-0

Explosive. Many reactions may cause fire or explosion. Gives off irritating or
toxic fumes (or gases) in a fire

Heating may cause violent combustion or explosion. May explosively
decompose on shock, friction or concussion. On concussion, from toxic fumes
including nitrogen oxides. Reacts with ozone causing explosion hazard.
Nitroglycol (NO3CH2-CH2NO3)

CAS number 628-96-6

Explosive. Gives off irritating or toxic fumes (or gases) in a fire.

Heating may cause violent combustion or explosion-producing toxic fumes
(nitrogen oxides). May explosively decompose on shock, friction, or
concussion.

Reacts with acids.
Nitroguanidine (NO2-NH-C=NH-NH2)

CAS number 556-88-7

DG cat. 1.3.2 Explosives and Blasting Agents, Nitro-compound

Dusts at sufficient concentrations can form explosive mixtures with air.

Containers may explode in the heat of a fire. This material poses an explosion
hazard when dry.
Nitrourea NH2(CO)NH-NO2

A rather unstable explosive material, insensitive to heating or impact, which gives
mercuric and silver salts which are rather sensitive to impact.
Ozonides

The presence of peroxidic impurities is thought to cause the violently explosive
decomposition.

A very few isomeric linear trioxide (ROOOR) are known, they are also explosively
unstable. Inorganic ozonides, salt of the radical O3- anions, are also hazardous.

Polymeric alkene ozonides are shock sensitive.

Ozonides are decomposed, sometimes explosively by finely divided palladium,
platinum or silver.
Perchlorates of Heavy Metals (MClO4)

DG cat. 5.1 Oxidizing Substances

Contact with reducing agents may cause extremely violent combustion. Contact
with combustible materials, flammable materials, or powdered metals can cause
fire and explosion.

Sensitive to mechanical impact and friction.
Perchloric Acid (HClO4)

CAS number 7601-90-3

DG cat. 5.1 Oxidizing Substances

Not combustible, but substance is a strong oxidizer and its heat of reaction with
reducing agents or combustibles may cause ignition. Can react with metals to
release flammable hydrogen gas. Reactions may cause fire and explosion.

The anhydrous form of Perchloric acid is a serious explosion hazard due to its
unstable nature and ability to react violently with many organic materials.

Hot Perchloric acid is a strong oxidizing agent and its oxidizing power increase
with increasing in temperature.

All work with concentrated Perchloric acid requires special precautions such as
use of Perchloric acid fumehood which installed with a water wash down system
such as scrubber.
Picric Acid C6H2(NO2)3OH

CAS number 88-89-1

DG Cat. 5.1 Oxidizing Substances

Common use as Bouin's Solution in histology and pathology laboratories.

Water content less than 30% is classified as explosive substance.

Dangerous explosion hazard when dry. Becoming increasingly shock, heat and
friction sensitive as it loses its moisture.

Store in non-metal containers and wet screw tops before sealing to prevent
formation of dry picric acid around the cap.

Incompatible with metals including copper, lead iron and zinc (corrodes the metal
to form shock sensitive metal salts); aluminum and water (ignites after a delay
period), ammonia and concrete (forms explosive salts such as calcium picrate).
Picric Acid Paste
Rusty Picric Acid container with an obsolete
manufacturing date