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Subject: Mothproofinging


From: Mary Ballard <ballardm<-a>
Date: Thursday, December 23, 2004
Victoria Gill <endangeredtextiles [at] ozemail__com__au> writes

>I have recently been working on some relatively contemporary woollen
>textiles works (tapestries, weavings and cross stitches)  all of
>which incorporate yarn which has been mothproofed. I suspect the
>chemicals most likely used are Dieldrin methoxychlor (brand name
>Mitin FF) Eulans or/and even DDT. These compounds are all organo
>chlorides, long lasting and washable. ...

Long answer: I looked into various chlorinated and a few
non-chlorinated mothproofing agents (ICOM-CC 1984,  "Mothproofing
Museum Textiles") and I found some confusion because not all
chlorinated products were water soluble nor fast to washing ('low
washfastness'). DDT and Dieldrin were, if I remember correctly,
soluble in drycleaning solvents, not water. Thus, *handling* would
expose me to the pesticide--the stuff would be as happy to come off
on my hands as to stay on the fiber. In dye terms, these agents are
not substantive to the fiber.

Washing (wet cleaning)would not be effective, but would give you a
contaminated waste water problem. Drycleaning might resolublize your
agent. Some agents, like DDT can also crystalize out--and might be
vacuumed off.  At the other end of the spectrum, Mitin FF (a
substituted urea with dichlorophenyl ether) and Edolan U (Eulan U33
in Europe, a chlorophenyl ether with methyl sulfonamide) are
different. They are  substantive to the fiber, like a dye. Mitin FF
is applied at the boil, but Edolan in warm water, as an
aftertreatment (the term 'aftertreatment' refers to after
manufacture, not in the loose fiber stage. Some aftertreatments are
suitable for conservation uses, some are not.

Edolan U was feasible but its potential toxicity for applicators and
its waste water effluent led to its removal from the market. (Some
natural history museum staff were spraying on Edolan U in an
isopropanol solution, but this would not be substantive to the fiber
(or fur)--leading to a problem with handling the stuffed animals.) I
have not been focusing on the issue recently but recollect the use
of 11% pyrethrin as the only mothproofing aftertreatment agent
currently available. This is a skin irritant and not substantive to
the fiber. It will bleed off in washing--it may be removed to your
wash water; pyrethrin breaks down with ultraviolet light and is

Before disposal, you would have to review the label directions
carefully. Pyrethrin, the Edolan/Eulan U33, and the Mitin FF will
cause slightly faster yellowing of wool than would otherwise occur
with light ageing. Of course, for long undisturbed display of large
cumbersome, fragile wool handings and carpets such yellowing may be
preferable to carpet beetle or clothes moth infestations.

Barbara Reagan did a wonderful job with a group paper for the AATCC,
"Effect of Insecticides on the Colorfastness of Acid and Disperse
Dyes on Nylon and Polyester" can be found in the Textile Chemist and
Colorist January 1984, Volume 16, Page 25+ (available at

Acid dyes are also used on wool. Though the substrate (wool vs.
nylon or PET) affects the outcome, you will find which agents
altered the dyes the most egregiously. Short answer: Slightly more
yellowing of wool; mothproofing agents were not widely used on
cellulosics (why waste money, time, chemicals?). Wash your hands
frequently (wear disposable gloves and dispose of them), use a HEPA
filtered vacuum cleaner, look for crystallinity, find out whether
the objects were commercially treated (aftertreated) or treated by
drycleaners, homeowners (DDT, etc).

Get an organic chemist to run an extraction for gas chromatography
and/or get an inorganic analysis for halogens on materials that you
question. Your agricultural extension service (pest control) and
industrial hygienists (health department) should provide you with
additional advice once you have identified your specific concern.

                  Conservation DistList Instance 18:29
                Distributed: Wednesday, January 5, 2005
                       Message Id: cdl-18-29-001
Received on Thursday, 23 December, 2004

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