Bugs are among the most unwelcome guests in homes and gardens. Insecticides might be a quick fix, but here’s the twist: While these chemicals are effective against insect pests, they can also pose a risk to humans and pets.

The Illinois Poison Center (IPC) handles over 1,000 exposures to insecticides every year. Our experienced staff have heard it all—from toddlers licking ant traps like candy to folks believing “more spray equals more dead bugs” to storing insecticides into drinking bottles (yikes!).

IPC pharmacists and nurses can provide information and recommendations for any toxic (and non-toxic) exposures to these bug-killing products. Most calls from the public are about the following classes of insecticides:

• Pyrethrins and Pyrethroids
• Organophosphates
• Carbamates
• Chlorinated Insecticides

Pyrethrins & Pyrethroids: Nature-Inspired but Not Risk Free

By far, pyrethrins and pyrethroids are the most common insecticide exposures and account for nearly 60% of insecticide cases reported to IPC. This is likely because they are the most widely used agents in homes.

Pyrethrins and pyrethroids are the active ingredients in roach, ant, fly, wasp, mosquito and flea sprays and bombs. Pyrethrins are derivatives of chemicals in chrysanthemum flowers and pyrethroids are their long-lasting, synthetic cousins. These products are of low toxicity to humans but can cause allergic reactions and/or irritation to the skin or eyes. Occasionally they can cause coughing and wheezing in patients with respiratory problems or if large amounts of powder or aerosol are inhaled.

Not so fun fact: These products can be extremely toxic to cats.

Safety tips for using pyrethrins/pyrethroids:

• Avoid inhaling sprays; ventilate well during and after application.
• Remove pets and children from treated areas and allow surfaces to dry completely before reentry.
• Wear gloves and wash exposed skin thoroughly after use.
• Call IPC or your regional poison center at 1-800-222-1222 if symptoms develop after exposure.

Organophosphates: Highly Effective, Highly Dangerous

Organophosphates are potent bug killers and—this might raise a few eyebrows—they’re closely related to military nerve agents. Commonly used in agriculture, organophosphates such as malathion and chlorpyrifos (now restricted for residential use) are extremely toxic and pose serious health risks to humans, even in small doses.

These chemicals inhibit a critical nervous system enzyme (i.e. acetylcholinesterase), leading to overstimulation of certain nerves in both insects and humans. Doctors use the memory aid “DUMBELS” to remember the effects of these agents:

• Diarrhea/Diaphoresis (sweating)
• Urination
• Miosis (pinpoint pupils)/Muscle weakness
• Bronchorrhea/Bronchospasm/Bradycardia (the Killer Bs)
• Emesis (vomiting)
• Lacrimation (excessive tearing)
• Salivation

Having uncontrolled sweating, urination, vomiting and diarrhea sounds like an absolutely awful experience. However, the shortness of breath caused by Bronchorrhea (excessive watery mucus from the lungs), Bronchospasm (tightening of the lungs airways) and Bradycardia (slow heart rate) can kill a person, hence the nickname of the Killer Bs.

Safety tips for using organophosphates:

• Never use agricultural insecticides indoors. Doing so will cause illness.
• Only use these products outdoors and wear full protective gear. These products can persist in the environment.
• If you suspect poisoning, call IPC or your regional poison center immediately at 1-800-222-1222. Time is critical in these cases.

Carbamates: The Less Intense Cousin of Organophosphates

Carbamates (e.g. carbaryl, propoxur) are close relatives of organophosphates and are used in some garden and household bug products. These products degrade much faster than more toxic organophosphates. While these products can cause similar nerve-related symptoms listed above, the chemicals quickly break down in the body, reducing the time you would experience symptoms.

Safety tips for using carbamates:

• Only use products clearly labeled for home use and follow instructions carefully.
• Keep children or pets away from treated areas until safe to return per product label instructions.
• Wash hands, tools and clothing thoroughly after application.

Chlorinated Insecticides: Mostly Banned, Still Can Be Dangerous

Most products in this category are outdated and include chemicals like DDT, aldrin, and chlordane, which are mostly banned now due to their toxicity and long-term environmental effects.

Lindane is a chlorinated insecticide still used medically as a second-line treatment for head lice and scabies after first-line treatment has failed. If used correctly, it should not be toxic to humans. However, if used incorrectly or ingested, toxicity can occur. Mild symptoms can include nausea, vomiting and headache. Symptoms from severe poisoning can include seizures, slow or shallow breathing, and coma.

Safety tips for using chlorinated insecticides:

• If you find a dusty can of DDT in the garage, call your local hazardous waste center for disposal.
• Don’t use unlabeled or mystery sprays.
• If you are prescribed lindane as a second-line treatment for lice or scabies, follow instructions exactly. Apply and remove the medication in the recommended time frame.  
• If in doubt, call IPC or your regional poison center at 1-800-222-1222.

If something goes wrong and someone has been exposed to an insecticide:

• If inhaled: Move the person to fresh air immediately. Seek medical attention if they have difficulty breathing.
• If it gets on the skin: Remove contaminated clothing and wash the skin with soap and water.
• If it gets in the eye: Rinse eyes with water for at least 15 minutes and seek medical help.
• If swallowed: Do not induce vomiting. Call the poison center immediately.
• Call IPC or your regional poison center at 1-800-222-1222. We are available 24/7 and your call is free and confidential.

Insecticide Prevention Tips:

• Check your cabinets and read the ingredients of any insecticide in your home to assess the risk to your family.
• Read labels carefully: Know what you’re using, how to apply it and what protective equipment is required.
• Store safely: Keep all insecticides in their original containers, out of reach of children and pets, and in locked cabinets.
• Use protective equipment: Always wear gloves and, if required, a mask or eye protection.
• Ventilate the area: Open windows and doors when applying sprays or foggers indoors.
• Don’t mix products: Mixing chemicals together can create toxic fumes or reactions.
• Dispose responsibly: Take expired or unwanted insecticides to designated hazardous waste facilities. Never pour them down the drain or in your yard. Do not burn insecticides in a fire.  

Insecticides are powerful tools—use them with respect and caution. Preventing accidental exposure is far easier and safer than treating it. Call IPC or your regional poison center at 1-800-222-1222 for advice if you’re unsure about a product or if an unexpected exposure occurs.

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