Re: Alcohol volumes

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From:Tim Morken <> (by way of histonet)
To:histonet <>
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Contrary to your feelings that "Thus, for
all but the smallest hospitals and labs, there should be few
restrictions because of space-related alcohol volume limitations" most
labs I've been in are easily over the limit. You have to consider that
most labs have 1) a weeks-worth of alcohol and xylene on hand for each
tissue processor and stain setup and 2) each stain setup is usually more
that a gallon of total solvents. I would bet that there are few labs in
compliance. Extra safety cabinets don't help because if you have too
much stored you will still be over the limit. Now, what if you have a
distiller in the vicinity as well?

At the last hospital I worked at we had three processors and two stain
setups. We had eight gallons of solvents on each processor and enough on
hand to change each once a week, rotate some solvents once a week and
enough on hand to keep the stain setups in good shape. That amounted to
about 70 gallons of solvents in all in a lab of 40 x 30 feet (1200 sq
ft). That's about three times the amount "allowed" by regulations. In
fact, I estimated that we would barely be within the regulation if we
stored no solvents at all!

The only solution we could come up with was to store all our solvents in
another room. Unfortunately, we didn't have another room nearby which
qualified as a flammables storage room. In fact, the nearest qualifiying
area was in a warehouse a quarter mile away.

We reduced our solvents on hand but still not enough to be within the

Tim Morken, B.S., EMT(MSA), HTL(ASCP)
Infectious Disease Pathology
Centers for Disease Control
1600 Clifton Rd.
Atlanta, GA 30333


FAX:  (404)639-3043

----Original Message Follows----
Date: Mon, 30 Nov 1998 19:46:36 -0600
From: Mathew Osborn <> (by way of Histonet)
Subject: Alcohol volumes


Recently a question was posed regarding the allowable volumes of alcohol
in a lab.  I hope what follows sheds some light on this issue.

Ethanol is classified as a Class IB combustible liquid. Class IB liquids
have a maximum allowable container capacity of 20 liters in "metal (non
approved) or approved plastic containers, safety cans or DOT spec metal

The amount of combustible liquids allowable is determined by the size of
the "laboratory unit". For hospitals with sprinkler systems, per 100 sq.
feet of lab space, Class I, II and IIIA (including IB) flammable liquids
are limited to 4 L (1.1 gallons) not in approved storage containers or
safety cans and 7.5 L (2 gal) total including quantities in storage
cabinets and safety cans. That is, only half of the combustibles in a
can be outside of approved storage containers. Note that there is no
governing total volume except as it pertains to lab area and to

The key definition here is "laboratory unit". Some EH&S officers define
laboratory unit roughly as the space enclosed by fire doors. Thus, for
but the smallest hospitals and labs, there should be few restrictions
because of space-related alcohol volume limitations. As an example, one
Sakura VIP has 21 L of ethanol and 9 L of Xylene (Class IIIA). Assuming
that a tissue processor is not an approved storage container, this means
that the "lab unit" would need to be a minimum of 750 sq. ft. (30x25
for each tissue processor to be "legal" ((30 L =F7 4 L) X 100 sq. ft. ).
a tissue processor that is considered to be an approved storage
then the space requirements are halved.

I hope this helps to answer the question.

If you have concerns or questions about cost effectively recycling these
solvents, please contact me.


Matt Osborn
Product Manager
Naiad Technologies, Inc.

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