Mothballs are small balls of chemical
pesticide and
deodorant used when storing clothing and other articles susceptible to damage from
mold or
moth larvae (especially
clothes moths like
Tineola bisselliella).
Their use when clothing is stored out-of-season gave rise to the
colloquial
usage of the terms "mothballed" and "put into mothballs" to refer to
anything which is put into storage or whose operation is suspended.
Composition and safety
Older mothballs consisted primarily of
naphthalene, but due to naphthalene's flammability, modern mothballs instead use
1,4-dichlorobenzene
(also called para-dichlorobenzene, p-dichlorobenzene, pDCB, or PDB).
Both of these ingredients have a strong, pungent, sickly-sweet odor
often associated strongly with mothballs. 1,4-Dichlorobenzene and
naphthalene should not be mixed, as they react chemically to produce a
liquid which may cause damage to items being preserved.
[1] Camphor, an insect repellent, can also be used as a less-toxic ingredient in mothballs.
Both naphthalene and 1,4-dichlorobenzene
sublimate, meaning that they evaporate from a solid state directly into a gas; this gas is toxic to moths and moth larvae.
For either of these insecticidal chemicals to be effective, they need
to be placed with the clothing in a sealed container so the vapors can
build up and kill the moths. In a sealed atmosphere like this, the
vapors are not as harmful to people because they are relatively
contained. The main exposures would occur when filling or opening the
containers, or from wearing clothes immediately after opening
(especially a problem for infants). A possible solution is to open the
containers outside and let the clothes hang and air out for a day before
wearing, though this practice will also expose the clothes to any moths
that may be flying about, risking re-infestation.
Uses and risks
In addition to repelling or killing insects such as moths and
silverfish, mothballs have been used as a stovepipe cleaner, snake repellent, and to keep away mice or other pests.
[2]
The main concern about the use of mothballs as a snake, mouse, or
animal repellent or poison is their easy access to children, pets, and
beneficial animals. Leaving them in a garden or in a living space
unprotected makes it very easy for unintended victims such as children
and pets to gain access to them. Mothballs are highly toxic when
ingested (they have a sweet taste, making this more likely), and will
cause serious illness or death. In addition to this, using a very large
quantity of mothballs in a basement or a living space may cause serious
respiratory problems in people living in the space.
[3]
Mothballs have been promoted as a
squirrel
repellent, and are an ingredient in some commercial repellent products.
They are generally ineffective, and are no substitute for physical
measures to exclude squirrels from building interiors.
[4]
Mothballs are a neurotoxin - especially those made of
para-dichlorobenzene - and need to be treated as such. Mothballs have
also been found to be
carcinogenic.
[5]
Mothballs have been used for
solvent abuse by adolescents, causing a variety of neurotoxic effects.
[6][7]
Older-formula mothballs have also been used by drag racers to enhance
the octane value of fuel by dissolving the mothballs in some of the
fuel and filtering out the remains with a filter paper. In the
Mythbusters episode "
Scuba Diver, Car Capers", it was shown to be "plausible" that adding mothballs to a car's fuel tank would increase its
horsepower.
It
sounds great, especially if you have a grudge against someone. The
problem with this rumor is that it simply isn't true. As it turns out,
sugar doesn't dissolve in gasoline. Pouring sand into the gas tank would
have about the same effect as pouring in sugar. The sand or sugar might
clog up the filter, and that could disable the car, but it's not a sure
thing.
