For many years I
have worked to discourage people from using “mothballs” to repel animals from
their homes and gardens. I am now
seeing articles on line encouraging people to use them in the garden for all
sorts of things from deterring Japanese beetles to scaring away squirrels. Mothballs are about the farthest thing
imaginable from a safe, natural way to repel pests. I personally wouldn’t use them in the house
even to discourage clothes moths.
one of two ( sometimes both) highly toxic chemicals, naphthalene and Para
dichlorobenzene. These chemicals are
classified as hazardous and a possible carcinogen by the EPA. There are sometimes other hazardous chemicals
in mothballs too. Pesticides, which mothballs are, (they are not a repellant,
they kill insects), are labeled as to how to use the product and by law they cannot be used any other
Mothball boxes, if
you read them, do not list the use of the product outdoors, or to repel
animals. So if you use them in this way you are breaking the law. If you
instruct people to use them in a non-approved way you are also breaking the
But breaking the law
is not the most important consideration. These chemicals do serious damage to
humans and other animals exposed to them. They can be absorbed through the
skin, inhaled, or ingested. The amount of damage done varies as to exposure and
who is exposed, but severe and fatal consequences can occur.
The chemicals in
mothballs can cause hemolytic anemia, damage to the liver and kidneys,
neurological damage, cataracts and damage to the retina. Children, pets, people
who already have liver or kidney problems or some forms of inherited blood
disorders are at special risk. Deaths have occurred from naphthalene and Para
dichlorobenzene exposure in both children and adults.
Using a lot of
mothballs in an attic or crawl space may allow toxic fumes to enter the living
area and just breathing those fumes can be hazardous. When people place
mothballs outside in an attempt to discourage animals they are exposing
themselves, children and pets to possibly fatal reactions. The chemicals also
pass through the placental barrier and a pregnant woman who handles mothballs
or even exposes herself to the fumes for an extended period of time can damage
Soil that is
contaminated with dissolved mothballs is also toxic; plants should never be
consumed if they are grown in soil contaminated by mothballs. It’s not known
how long the contamination remains in the soil.
If you can smell the
mothballs you are inhaling vaporized poison. If a child or pet swallows just
one mothball it can cause serious problems and the poison hotline should be
called immediately. (1-800-222-1222). The pesticides in
mothballs can be absorbed through the skin by children handling them or pets
walking on them. Never put them in pet’s
beds or store them with pet food. Don’t
use them in any food area.
Mothballs are a
toxic pesticide and should be treated as such.
They are definitely not an organic or safe solution to garden or pest
problems. They are intended to be used
in an enclosed area to prevent insects from eating stored clothing. Read the
label on the box and follow it. Even
though your grandmother used them all over the house doesn’t mean they are
safe. Your grandparents also used DDT without knowing the consequences. And the
old wives tale of discouraging animals with mothballs doesn’t work most of the
pesticide hotline page on toxic effects of mothballs.