Mothballs are nearly 100% active ingredient, and the active ingredient may be either naphthalene or paradichlorobenzene. Each active ingredient can cause different health effects if the exposure is high enough. Mothballs slowly turn from solids to toxic vapor. When you smell mothballs, you are inhaling the insecticide. Mothballs can also be dangerous if they are chewed or eaten. Children, pets and wildlife may mistake them for food or candy and eat them. One mothball can cause serious harm if eaten by a small child.

If someone has swallowed a mothball, call the Poison Control Center at 800-222-1222 for emergency medical advice. If you think your pet has eaten a mothball, contact your veterinarian or one of these emergency resources.

Additional Resources:

If you have questions about this, or any pesticide-related topic, please call NPIC at 800-858-7378 (8:00am - 12:00pm PST), or email us at npic@oregonstate.edu.