Primary Explosives Safety

[Ech0Sierra]

How do all of you go about handling these sensitive materials with a minimum risk of ignition or detonation? I've tinkered with a lot of secondaries, but am so far unsure how to go about safely producing and handling small amounts of primaries for detonators, blasting caps, and the like.

[fuckbiscuit]

Anti-static spray and do it in a location where there is no items hanging overhead or strong light (fire, duh). Don't store any primary's in jars ( we all know how good things can turn rotten when AP recrystallises on the threads.)

Just use HMTD/KN03 its relatively safe if you handle it with care.

[Ech0Sierra]

When an explosive is referred to as "friction sensitive" does that mean that movement inside a container will detonate it? Or does it mean something else?

[fuckbiscuit]

When an explosive is referred to as "friction sensitive" does that mean that movement inside a container will detonate it? Or does it mean something else?

It depends just how much force was put into shaking it, but even then a powder explosive isn't going to det (unless it's generating static.).

Friction sensitive generally apply's if there is force exerted directly onto the product in question. But it can go on just how sensitive the chemical you're handling is.

[HereToDisagree]

Choosing a safe primary is probably one of the most important safety steps you can take. Which primary you use will probably depend largely on how cautious you are and what materials and equipment you have available.

There are several methods for judging the safety of an explosive. Some of the most common standards include thermal stability (usually expressed as the temperature at which an explosive will decompose or detonate), sensitivity to impact, friction, and electrostatic discharge.

Sensitivity to impact is usually measured by placing a small amount of the explosive to be tested on a small metal plate. Above this plate is a metal weight. The weight is drawn to a certain height above the explosive and dropped. On each drop, the weight is elevated slightly. Sensitivity to impact is usually expressed as the height at which a given weight will detonate the explosive in question a certain percentage of the time. For instance, PETN will detonate 25% of the time when a 2.5kg weight is dropped onto it from a height of 14 cm.

Sensitivity to friction is usually determined by placing the explosive in question on a sliding plate. A small amount of the explosive in question is placed upon this surface and another plate is placed parallel to the first on top of it. In this case, the friction sensitivity is measured as the mass which must be applied to two parallel surfaces such that the sliding of the the plates will cause a 50% chance of detonation. For instance, PETN will detonate 50% of the time when a porcelain plate with 5800g placed upon it is slid across the surface of the bottom porcelain plate. Another common method for determining friction sensitivity is to use a roller or a wheel in a fixed position. A plate is then slid underneath the wheel, crushing the explosive between the two surfaces.

Electrostatic discharge sensitivity is usually expressed in joules of energy required to initiate an explosive via spark a given percentage of the time. For instance, a .02 J spark is required to detonate HMTD 50% of the time.

The two explosives most commonly used by amateur pyros are probably HMTD and AP. I suspect this to be largely due to the ease with which they can be synthesized, and not their explosive properties- they're both relatively unsafe. HMTD has the unfortunate property of extreme friction sensitivity. During testing HMTD detonated when the two plates were slid across each other with no weight added. Acetone peroxide has a rather unfortunate volatility, in addition to high sensitivities across the board.

Lead azide and lead styphnate are or have both been used as primary explosives, but they hold the danger of extremely high sensitivity to electrostatic discharge. Lead styphnate was able to detonate from a mere 0.0002 J discharge, and lead azide was not much better at 0.0047 J. Compare this to 0.2 for HMTD (or just about any other explosive for that matter- very few explosives are as sensitive to static electricity as these two lead compounds).

There's a whole plethora of various primary explosives out there- literally dozens to choose from. I'd recommend doing some research on what you can make with the chemicals and equipment available to you, and then researching in detail the sensitivity figures for those explosives. If there is nothing suitably safe you can make, you may want to consider holding out until you have a better lab.

In addition to the normal sensitivity figures for an explosive, also check for any other important properties, such as volatility, whether it is hygroscopic, how easily it can DDT, sensitivity to light, chemical incompatibilities (HMTD is said to react with most metal surfaces), and toxicity.

I'm personally a fan of the nitrotetrazole complexes :D These tend to be very thermally stable, insensitive to electrostatic discharge, insensitive to impact, and most of them have high values for friction as well (although a couple of the complexes have friction sensitivity in the 20-40g range, most of them are over 500g, with some as high as 4200g). Fortunately, some of them DDT very easily (and unusually quickly), and detonate with extreme force (most of them have a higher VoD than TNT).

THE TL;DR VERSION: AP and HMTD aren't nearly as safe as some other primary explosives- research what is available to you and make something safer. There's a lot of options out there, invest some time at google to figure out what is best for you.

[Ech0Sierra]

Thanks for the help. I'm trying not to rush in like an idiot and go "ZOMG TATP I CAN BLOW SHIT UP NOW!!!!11!1". Right now I'm just trying to find the best balance of ease of production and safety. So friction sensitive is usually referring to sensitivity when the explosive is between two weights and rolled around. I originally thought it referred to just movement of the explosive in the container, with the weight/friction of the particles being sufficient to detonate it. I currently have the means to create TATP and HMTD, not much else, but I'm thinking right now the best solution is to keep it wet until needed for use.

[fuckbiscuit]

Thanks for the help. I'm trying not to rush in like an idiot and go "ZOMG TATP I CAN BLOW SHIT UP NOW!!!!11!1". Right now I'm just trying to find the best balance of ease of production and safety. So friction sensitive is usually referring to sensitivity when the explosive is between two weights and rolled around. I originally thought it referred to just movement of the explosive in the container, with the weight/friction of the particles being sufficient to detonate it. I currently have the means to create TATP and HMTD, not much else, but I'm thinking right now the best solution is to keep it wet until needed for use.

Not unless you had a very deep container :p

.....or nitrogen triiodide.

[Ech0Sierra]

My wee brain once thought ALL explosives described as "friction sensitive" were as unstable as nitrogen triiodide. The container won't be too big, at most 2 ml. So keeping it wet is the way to go?

[fuckbiscuit]

My wee brain once thought ALL explosives described as "friction sensitive" were as unstable as nitrogen triiodide. The container won't be too big, at most 2 ml. So keeping it wet is the way to go?

Nitrogen triiodide can be detonated by its own weight, flash powder is friction sensitive; it cannot. Not all compounds are incredibly volatile just because they're labelled as friction sensitive.

EDIT: sorry didn't answer your question, yeah make a suspension and recrystallise when you intend to use.

[Sentinel owl]

Good thread on tetrazoles:

http://www.sciencemadness.org/talk/viewthread.php?tid=12938

[nuclearrabbit]

Not unless you had a very deep container :p

.....or nitrogen triiodide.

I remember an old fool who kept over a mole of AP in a little frosting container. He lived to tell you this. ;)

[lordnitrox]

I remember an old fool who kept over a mole of AP in a little frosting container. He lived to tell you this. ;)

oh god dude, I'm so shocked you lived.

[Anders Hoveland]

Explosives which will easily explode by being hit, or by exposure to flame, are known as primary explosives. These types of explosives are potentially very dangerous to work with. While some of these substances can seem moderately safe, many of them are unpredictable in their sensitivity to detonation. Substances which neither burn nor explode when lit with a match, can later detonate from ambient static electricity on a day with low humidity. Substances which do not explode when thrown against a hard surface, can later detonate when they are gently and cautiously mixed, sometimes even when wet. Sometimes an primary explosive will detonate for seemingly no reason when left in storage after several months. But usually, accidents care caused when a lid is removed from a container containing the substance, or when the solid primary explosive is being divided into smaller portions. Even very careful handling of primary explosives can still result in accidents. There are many complicated factors that can greatly increase the sensitivity and danger of a primary explosive substance over time. If a sample of the substance does not easily explode, this does not mean that the substance is safe. The sample could later explode from the slightest touch after hours, days, or even years.

Never work with a quantity greater than 5 grams of any primary explosive.
This in no way implies that 5 grams is a safe quantity!! A safer quantity to work with is closer to about 500 milligrams (one half gram). Keep your hands away from the sample at all times! For less than 2 grams, never touch the substance, even with gloves. For quantities more than 3 grams, keep a distance of at least 20cm away from the sample, and be sure to waer safety goggles to protect your eyes (goggles are actually recommended whenever handling any explosive compound). It is also recommended not to use metal tools or containers for working with potentially sensitive primary compounds, since detonation could send dangerous sharp metal fragments flying out at high speed. If possible, try to use a plastic container. This is not always possible when performing nitrations, since nitric acid may burn through the plastic.

Be sure you know the proper precautions that need to be taken, and the things not to do, before working with any primary explosive. While an accident might be unlikely, many younger people have suffered severe injuries (losing fingers, suffering permanent ear damage, or losing sight in an eye, and even death).

One particular note, while acetone peroxide is very simple to prepare, it is one of the most dangerous primary explosives to handle, being far more sensitive than nitroglycerine. A teenager in Sweden killed himself when handling a over a kilogram of this dangerous substance. Please never prepare or store more than 2 grams of this substance (about the size of a large spoon full)!! Sometimes this substance can be thrown against a hard surface without incident, while other times it can detonate when being cautiously divided with a thin plastic playing card.

Another safety tip is to wear only cotton clothes when handling primaries that are very sensitive to static discharge, and preferably avoid handling such compounds on days when the humidity is very low (when the air is dry).

When moving a small quantity of a highly sensitive primary, the substance can be placed into a large paper bag at the bottom, and the bage can be held away from the body which is carrying it.
In this way, if there is an accidental detonation, there will be plenty of space between the substance and the person carrying it. Keeping your fingers a distance of only 5cm away from a small quantity of sensitive explosive can provide much protection if something should go wrong. To provide confinement for the small quantities of primary, use a small tube made of rolled up paper. Doing this (rather than using a plastic container) will prevent dangerous hard fragments from shooting out if the substance detonates.

Good genral rules: only use very small quantities and keep fingers at least 5cm away at all times. Plastic tableware could be used to manipulate quantities under 0.5g. Something longer should be used for 1-2g.

If acetone peroxide is being stored, use a plastic bag and do not store more than 0.5g of the substance. Be sure the powder is fluffy and loose, and not all piled together in one corner of the bag. In this way, if ambient static charge should ignite the substance, it will be less likely to detonate. This is also a way to seal the substance, otherwise the solid slowly evaporates into the air. Never use a jar or stopper. Crystals could sublime onto the lid and then detonate when the lid is forcefully removed.
Acetone peroxide that is more than a day old can be more dangerous because it has had time to fully dry and possibly crystallize more.

ETN and MHN can be absorbed into a small quantity of nitrocellulose, which makes the compounds more resistant to impact for increased safety. (the liquids can later begin to leak out of the nitrocellulose making the substance as dangerous as before)

Finally, (hopefully this should be obvious) never store primary sensitive compounds near larger quantities of less sensitive energetic material. The primary could spontaneously detonate for a variety of reasons, keeping the two separated will prevent the larger quantity from being detonated. Do not insert the primary until immediately before use, and only after the main charge has been placed on the ground. Ensure that the paper case that contains the primary will easily and effortlessly slide into the main charge. Trying to force the primary into place could be disasterous.