[Histonet] Cryostat decontamination...

[Liz Chlipala]

>From what I understand if you require that an individual wear a N95
respirator when they are sectioning frozen sections then you are also
required to have that respirator fit tested yearly.  

We are a research lab that does quite a bit of work on TB samples.  We
do not section TB infected samples on a cryostat.  All samples that we
receive have been fixed in 10% NBF for several days and then transferred
to 70% alcohol.  When I was in a clinical lab, we would not section
frozen sections of lung samples if they wanted to rule out TB, the
pathologist would recommend to process to paraffin first.  In fact since
the samples are generated in a biosafety level 2 or 3 facility, they can
not leave that facility unless the samples have been fixed and rendered
non infectious.  Frozen sections would need to be prepared within that
biosafety facility with all of the appropriate PPE's in place.  The
University that we work with has tested these samples via culture after
their fixation and alcohol procedure.  We do however offer the N95
respirator to the techs and they can wear it if they want to, when they
are grossing, embedding or sectioning these samples.  But since it is
voluntary we do not have to fit test, we have a specific procedure that
covers this.  This protocol has been developed with the help of our
local OSHA rep.  The other thing is we use a special vacumme with a hepa
filter to vacume up the paraffin trimmings.  OSHA has a program for
small businesses and will work with them to make sure that they are
within compliance, they have been very helpful to us here.  Just go to
the OSHA website.   

Liz

Elizabeth A. Chlipala, BS, HTL(ASCP)QIHC
Manager
Premier Laboratory, LLC
PO Box 18592
Boulder, Colorado 80308
office (303) 682-3949 
fax (303) 682-9060
www.premierlab.com
 
 
Ship to Address:
1567 Skyway Drive, Unit E
Longmont, Colorado 80504

-----Original Message-----
From: histonet-bounces <@t> lists.utsouthwestern.edu
[mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of Tom
McNemar
Sent: Monday, November 16, 2009 12:17 PM
To: histonet <@t> pathology.swmed.edu
Subject: [Histonet] Cryostat decontamination...

Hello all,

We have always used absolute alcohol to decontaminate our cryostat and
wondered what others use.  This has been brought up by an article in the
September issue of CAP Today that talks about biosafety when doing
frozens (specifically talks about TB).  As a related question, how many
institutions require the wearing on an N95 respirator when doing
frozens?

The article states that diluted alcohol is more effective "because the
presence of water causes proteins to denature more quickly."  I just did
the decontamination of our cryostat last weekend and used 70% alcohol as
the article suggested.  The alcohol evaporated and I was left with
beads/drops of water that I had to then dry by hand.  I guess the
alternative would be is just to go over it again with aboslute after
usiing 70%.

The article goes on to recommend that personnel should wear N95 masks
that are fit tested on a yearly basis.

Thanks in advance.

Tom McNemar, HT(ASCP)
Histology Co-ordinator
Licking Memorial Health Systems
(740) 348-4163
(740) 348-4166
tmcnemar <@t> lmhealth.org
www.LMHealth.org


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