From: ahahma@polaris.utu.fi (Arno Hahma)
Newsgroups: rec.pyrotechnics
Subject: Re: Blasting Caps
Keywords: blasting caps lead azide
Message-ID: <1992Mar15.135517.10666@polaris.utu.fi>
Date: 15 Mar 92 13:55:17 GMT

In article <6574@sirius.ucs.adelaide.edu.au> Zoz@ucs.adelaide.edu.au writes:

>Can anyone tell me what is used in commercial blasting caps,
>detonators etc? Also, here's a

Lead azide, lead styphnate or diazodinitrophenol or mixtures thereof.
Base charge can be PETN, Comp. B or RDX or pentolite. Tetryl has been
used, hardly any more due to its toxicity.

>rather interesting bit of info courtesy of the safety chart on the
>wall of our Organic Chem lab: Lead Azide is only classed as an
>explosive when it contains more than 20-30% water. Does this mean
>lead azide only deflagrates when dry, or does it decompose
>non-violently if not kept wet?

??? I would not rely on that chart any more! Lead azide is an
explosive with any moisture content. Adding water does desensitize it,
but it is still an explosive. Lead azide NEVER burns quietly, it
invariably detonates on ignition, regardless of the amount. Wet lead
azide just does not ignite as easily as dry.

Water is added to lead azide to make is transportable. According to
regulations it is only allowed to transport it wet - this applies to
all of the primary explosives.

ArNO
    2

From: ahahma@polaris.utu.fi (Arno Hahma)
Newsgroups: rec.pyrotechnics
Subject: Re: Chemical and safety questions
Message-ID: <1992Aug20.110616.23460@polaris.utu.fi>
Date: 20 Aug 92 11:06:16 GMT

In article <1992Aug20.083235.19576@usenet.ins.cwru.edu> cd353@cleveland.Freenet.Edu (Norman Spiney) writes:

>Does any body know about the relative safety and chemical and
>physical properties of the following chemicals;

>a) DDNP
>b) TACC

>specifically, as TACC is a chlorate, will microscopic traces of
>inorganic acids cause unwanted decomposition (possibly explosive)

Acids will cause decomposition. Depending on the acid concentration,
the decomposition may lead to ignition or not. In any case, acids are
very harmful in contact with TACC and that is probably one of the
reasons this compound is not widely used.

>I have very little data on TACC. DDNP seems to be relatively safe
>to handle as it is used commercially, although I do not anything
>about safety and precautions in manufacture.

DDNP is also safe to manufacture, there is virtually no possibility of
an explosion due to errors in the manufacturing procedure. You would
have to really try blowing things up to get any trouble with that.
What is possible is a total mess, if the materials are spilled around.
(The raw materials are very effective dyestuffs as well). One of the
reactions is rather exothermic ( I assume picric acid as the starting
material) and may cook off on the table (experience ;-).

>Is DDNP a suitable replacement for PbN3? The latter is much
>easier to synthesize, but I do not like using chemicals

DDNP can be used as direct replacement for PbN6. It is slightly less
effective and requires considerably more pressing to function
properly. DDNP is also less sensitive against mechanical action (safer
to press) but much easier to ignite with a flame (static sensitive).

>containing heavy metals (Yes I do care about my health and that
>of the environment).

Well, the amounts of heavy metals you need are quite neglidgible
compared to any other source of pollution. While manufacturing PbN6
the lead is really not the hazard you are concerned about. The
hydrazoic acid (easily evolved in high enough concentrations) is the
compound you should be careful with (a nasty experience speaks again
;-).

>Mark.

ArNO
    2

Newsgroups: rec.pyrotechnics
From: nreitzel@lonestar.utsa.edu (Norman L. Reitzel   )
Subject: Re: azide salts
Message-ID: <1994May10.173316.24215@ringer.cs.utsa.edu>
Date: Tue, 10 May 1994 17:33:16 GMT

In article <2qms9v$od6@dingo.cc.uq.oz.au> fernee@dingo.cc.uq.oz.au (Mark Fernee) writes:
>bill nelson (billn@hpcvaac.cv.hp.com) wrote:
>: hankwang@pleasure.hacktic.nl (Han-Kwang Nienhuys) writes:
>: : Op 29 Apr 1994 schreef billn@hpcvaac.cv.hp.com:
>: :
>: : [sodium azide]
>: :  bh> It can be made from the acid - that was how it was first
>: :  bh> produced.
>: :
>: : Yeah, and how does one obtain the acid? Right, by treating NaN3 with sulfuric
>: : acid. :-)
>
>: Actually, it was first produced by reacting nitrous acid with hydrazine.
>: It is highly explosive, and tends to explosively decompose on storage.
>
>Hydrazoic acid is also very toxic and almost odourless. One report I have
>read states that when you smell it you are already poisoned. Hydrazoic
>acid formation when synthesising meavy metal azides should be carefully
>avoided.

I can tell you from personal experience that hydrazoic acid is anything
but almost odorless.  It has a sharp biting odor that reminds me in some
ways of chloramine, NH2Cl.  It's really strong, even in ppm concentrations,
and as you point out, it's -wazoo- toxic.  The MCB safety bullitins state
that if you can smell it at all, you should go somewhere else immediately.

I spilled about 10 ml of a 2% ether solution, and even after rinsing the
surfaces, you could smell it for -days-.  Unlike hydrogen cyanide, it
apparently does not cause olifactory fatigue, so you keep right on
noticing the odor.  Which, I suppose, is a good thing.

  ------------------------------------------------------------------------
  Norman L. Reitzel, Jr.       |    "When you live beside the graveyard,
  nreitzel@lonestar.utsa.edu   |       you can't cry for every funeral."
  Blue Water Ventures, dba.    |                         Russian Proverb
  ------------------------------------------------------------------------