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Subject: Morpholine in sprinkler system

Morpholine in sprinkler system

From: Lisa Mibach <perygrine>
Date: Friday, January 15, 1993
This may be an issue of some concern: see the articles by Norbert Baer
and Paula Volent  on film forming amines in the Journal "Museum
Management and Curatorship" published by Butterworths. (sorry, I don't
have the citation, but it was pre-1989; I have a hunch that librarians
have ways of tracking this down...)

Baer and Volent describe the problems caused by blowover of DEAE in the
humidification system at Cornell University Museum.
(diethylaminoethanol: a film forming amine, related to morpholine, used
to protect boilers and HVAC ducts from rust; morpholine is also used for
this purpose).

Occurrences have also been observed at the Univ. of Kentucky Art Museum,
Memorial Art Gallery in Rochester, and the Minneapolis Institute of
Arts, c. 1988.

These incidents involved a hazy film found on paintings, which is
analyzable by gas chromatography/mass spectrometry.  The paintings from
Cornell were cleaned at the Williamstown Regional Conservation Center.
I looked into this at some length on behalf of Kentucky and Memorial
when I was Director of the Intermuseum Laboratory in Oberlin, and
discussed how much of a problem this deposit might pose with Dr. Baer,
and with David von Endt and Tim Padfield, Conservation Scientists at the
Conservation Analytical Laboratory at the Smithsonian.

They confirmed that the film-forming amines are very polar organic
compounds which are strongly alkaline.  There is some debate about
whether these arrive at art surfaces as alkaline or acid materials, or
as salt precipitates formed by the reaction of acid gases on the
alkaline amines. Even in this latter case, moisture from the air would
cause the salts to become chemically active.  In addition, these amine
products may act in a hygroscopic manner, collecting moisture from the
air in microscopic droplets, leading to corrosion pitting in metals, and
grain expansion in wood.  Residues remaining on painting varnishes could
potentially cause swelling, with possible eventual penetration to the
underlying paint surface. Any exposed non-washable organic materials
(wool, leather, etc) are also potential candidates for micro-damage.

It is my opinion that the haze has been observed primarily on paintings
because these often have a dark, plain, background, and are exhibited at
such an angle that the haze is visible.  That doesn't mean that it is
not present on other, lighter-colored materials.  This haze is not the
same as "bloom" on paintings, although it appears to be similar at first
glance.  If you run your finger across it (on a dark painting), it
changes from a pale haze to a vaseline-like smear, possibly as the
deposition lattice is compressed and changes refractive qualities.  It
can be sampled on a Q-tip and analyzed by GC/Mass Spec in your local
Univ. chemistry dept. (I discovered inadvertently that I could test in
situ by sticking said finger in the corner of my eye: it stings.  I
recommend the Q-tip: chemistry department approach as being somewhat
more reliable and less painful.)

Unfortunately, I do not know of any spot test which could be used to
confirm the presence of the amines on light-colored materials, or to
ensure that removal is complete.  Perhaps someone out there has a
chemist friend who could devise a color-indicating spot test for us.

We tried to guess how long it might take for damage to begin, and two
years was suggested as a rough guess, but since one seldom knows when
deposition began, and since conditions and substrates are so variable,
two years could have arrived yesterday.

Removal: it appears that the amines may be sufficiently water soluble
(they are chosen for this solubility, because they are transported
through ducts in steam) to make thorough rinsing sufficient for removal,
assuming that the collection materials in question are washable, and
that washing does not have other, unintended, side-effects...  However,
I must urge that cleaning be carried out by trained conservators,
because of potential damage by water, and because of the possibility of
loosening and removing flakes of softened material.  In addition, simple
wiping of the surface with a damp cloth might "sandpaper" the surface
with atmospheric grit.


    1. Don't panic.. until you KNOW you have a problem...

    2. Consult with your building engineers to find out what materials
    are used to protect boilers in your humidification systems.

    3. Sample and analyze as above to find out if you _do_ have a
    deposit on collections materials.  If so, consult with a conservator
    to find out if this is likely to cause a real problem; the financial
    implications could be daunting.

    4. In the short term, try to cover any valuable exposed collections
    materials. (You DO have all your rare exhibits under glazing, don't
    you? Just like you DO back up your hard disk regularly???)

    5. Consult with your building engineers about the possibility of
    closing diffusers near rare collections, and allowing humidity to
    diffuse from adjacent areas.  I certainly would not recommend
    shutting off a main humidification system entirely; furthermore, the
    fluctuations of relative humidity induced by floor humidifiers
    cycling on and off might be a worse hazard than the amines.

    6. Discuss with engineers the possibility of changing or reducing
    the quantity of boiler protectants, or of capping steam lines from a
    central plant (the likely source of boiler treatment chemicals), and
    using the heat to generate localized steam for humidification using
    distilled water.

In sum, this is a problem which thus far is largely theoretical, because
only Baer and Volent have studied it, and because tracking down whether
it really constitutes a "clear and present danger" takes more time and
effort than most people have, particularly when the financial
implications of changing humidification systems or washing entire
collections tend to induce ostrich-like somnolence.

So don't go all crazy worrying; I just thought we could use a little
something to think about in the post-holiday doldrums... ::grinning

p.s. and this is all I know about it, but I would be most interested if
anyone has taken the question any further?

Lisa Mibach
Perygrine [at] aol__com

                  Conservation DistList Instance 6:38
                 Distributed: Tuesday, January 19, 1993
                        Message Id: cdl-6-38-002
Received on Friday, 15 January, 1993

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