POST 00617E : DESTRUCTION OF VACCINES
Follow-up on Posts 00603E, 00606E, 00609E, 00611E and 00614E
25 November 2003
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Henrik Oja (mailto:[log in to unmask]) shares his experience on
incineration following questions raised in the previous posting on the
subject (Post 00614E). This interesting contribution highlights the need
for a clear and detailed policy on this issue and for filling gaps
recognized in Post 00606E by Yves Chartier and Ãœmit Kartoglu among others.
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Regarding glass in incineration:
Glass indeed does not burn. We have been doing controlled lab testing of
our incinerator using hospital waste for a year, and glass is always a
problem. If you have a system that is fired with external fuel (such as
ours which uses liquid gas to reach the EU emissions specs) any glass will
result in very high localised temperature around the melted glass. If the
total amount of glass is not too high and the design of the system is good,
you can just remove the glass in conjunction with ash removal / maintenance
activities. Any glass may also result in poor final burning, as some of the
material may "cling" to the lump of glass and not end up as nice fine ash.
Particularly safety box cardboard can behave like this.
Glass in the ashes is always a safety risk for the operator. It may have
huge amounts of needles encased in the lump. It can also throw off shards
of glass as you remove it, because of stress created by uneven cooling.
This can occur even 24 hrs after burning.
If there is very much glass you may have problems with metal fatigue from
the high temperature and/or clogging or other problems in your grid system
if your incinerator has one. Explosions can be an issue and most definitely
will result in emissions bursts as the system gets unbalanced for a while.
The behaviour of a small ampoule at least in our experience is that the
aluminium cap will melt and seal the ampoule first, which of course will
subsequently result in a minor explosion after heating up sufficiently.
Our recommendation is definitely to do good segregation, and this cannot be
accomplished if you do not have the glass container right next to the
safety box. Since any waste management system will only be as good as the
practises and procedures that support it, this is just one item on the list
of things that need to work.
Henrik Oja/Mediburner
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