Formaldehyde bomb

[Koen A.L. De Smet]

Dr.W.H. Colledge wrote:
> 
> We wish to formaldehyde bomb our tissue culture room to eliminate an
> annoying sorce of low level contamination. Does anyone know where we can
> purchase the bomb? Many thanks.
> 
> --
> Dr. W.H. Colledge
> Physiology
> University of Cambridge
> Cambridge
> CB2 3EG
> 
> Tel. 01223-333881
> Fax. 01223-333840

We have a containment level three room, which we occasionally have to 
bomb with formaldehyde. 

For this, we use Laycock Fumigators from Tolbest Ltd, 10 Aston Court, 
Kingsland Grange, Warrington, Cheshire WA1 4SG. I presume you can also 
use them for tissue cultures. 

Just a few extra tips. We make sure we can seal the room up COMPLETELY, 
to leave the vapour in it for 24 hours. For this we put masking tape 
around both doors (inner andouter door of the lobby) and tape a plastic 
bag over the air inlet (windows are always sealed anyway..). The 
formaldeyhde doesn't get into our incubators.  At the end of the 24 
hours, we remove the seals and switch on the cabinets, FROM OUTSIDE THE 
ROOM (one cannot go in there without a gasmask).

You can also produce formaldehyde vapour by simply mixing formaldehyde 
with potassium permanganate. I am not sure of the ratios, but think it 
is around 25 ml and 10 g. This may have to be scaled up to do a whole 
room. Don't try this before you have verified these ratios, becuase it 
is a rapid exothermic reaction.

I hope this helps, but I am not prepared to take any responsibility if 
you have problems with formaldehyde escaping out of the room or any 
other hazards associated with this procedure!

Koen

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        Dr Koen A.L. De Smet
        Research Fellow
        Department of Medical Microbiology
        Imperial College Medical School at St Mary's
        Norfolk Place
        London W2 1PG
        Great Britain
                                     
        Tel: (+44)-(0)171-594 3946  
        Fax: (+44)-(0)171-262-6299   
        http://www.sm.ic.ac.uk/medmicro/home.htm
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