Snake-A-Way can be harmful to humans, primarily because it contains naphthalene, a chemical the EPA and the International Agency for Research on Cancer have both classified as a possible human carcinogen. The product is made of 7% naphthalene and 28% sulfur by weight, and both ingredients carry real health risks with repeated exposure, inhalation, or accidental ingestion. Making matters worse, university research has found the product doesn’t actually repel snakes, meaning you’re taking on chemical risk for little to no benefit.
What’s in Snake-A-Way
Snake-A-Way (sold as Dr. T’s Snake-A-Way Snake Repelling Granules) is a granular product you spread around your yard. Its two active ingredients are naphthalene at 7% concentration and sulfur at 28%, with the remaining 65% listed as inert ingredients. Naphthalene is the same chemical found in traditional mothballs, and it’s the ingredient that raises the most serious health concerns.
Health Risks of Naphthalene
Naphthalene damages red blood cells, changing or destroying them so they can no longer carry oxygen effectively. This can lead to organ damage. While a single brief outdoor exposure to Snake-A-Way granules is unlikely to cause poisoning, the risks increase with repeated use, enclosed spaces, or accidental ingestion.
Symptoms of naphthalene exposure can be delayed. Stomach problems like abdominal pain, nausea, vomiting, and diarrhea may not appear until two days after contact. More serious symptoms include headache, confusion, drowsiness, rapid heart rate, low blood pressure, shortness of breath, and yellowing of the skin. In severe cases, convulsions, reduced urine output, and coma can occur.
People with a genetic condition called G6PD deficiency (which affects roughly 400 million people worldwide, often without their knowledge) are significantly more vulnerable to naphthalene’s effects. Even small exposures can trigger a dangerous breakdown of red blood cells in these individuals.
Both the EPA and the International Agency for Research on Cancer classify naphthalene as a possible human carcinogen. That classification means there is enough evidence from animal studies and limited human data to raise concern about cancer risk with ongoing exposure.
Health Risks of Sulfur
Sulfur makes up the largest active portion of the product at 28%. It’s less dangerous than naphthalene but still irritating. Breathing in sulfur dust can irritate your airways and cause coughing. It irritates the skin and eyes on contact, and prolonged or repeated skin exposure can cause rashes or calluses.
Long-term inhalation of sulfur dust can irritate the nose and respiratory tract, potentially leading to chronic bronchitis. If the granules are ever burned (accidentally or otherwise), sulfur produces sulfur dioxide gas, which causes coughing, shortness of breath, sore throat, and labored breathing.
Children and Pets Face Greater Risk
The granular form of Snake-A-Way makes it particularly risky around children and pets. Small children may pick up and mouth the granules, and accidental ingestion of naphthalene is a medical emergency. Product labels specify storing the product in its original container in a dry place inaccessible to children and pets, but once spread across a yard, the granules are accessible to anyone. The product can also cause moderate eye irritation on contact and skin irritation in sensitive individuals.
The Product Likely Doesn’t Work
A controlled study at the University of Nebraska-Lincoln tested Snake-A-Way’s exact formulation on the most commonly encountered snake species in the test area, the plains garter snake. The results were definitive: naphthalene, sulfur, and the combination of both chemicals failed to cause any avoidance behavior. There were no statistically significant differences between treated areas and untreated controls (P = 0.849), meaning the snakes behaved identically whether the product was present or not.
The researchers went further, noting that applying Snake-A-Way could actually backfire. Snakes in their home territory simply ignore the chemicals. Over time, they associate the smell with familiar, safe habitat. When you then apply the same product near your patio or doorway, migrating snakes that have already learned to associate the scent with a safe home range may actually be drawn toward the treated area rather than away from it.
The study’s conclusion was blunt: usage of these repellents should be discouraged. The researchers recommended education and habitat modification (removing debris, sealing gaps, reducing rodent populations) as the most effective and intelligent approach to reducing snake encounters.
Safer Alternatives to Snake-A-Way
Since the chemical approach carries health risks without delivering results, habitat modification is the better path. Snakes are attracted to areas that offer food and shelter, so the most effective steps are practical ones:
- Remove hiding spots like rock piles, wood stacks, and tall grass near your home
- Seal entry points including gaps under doors, cracks in foundations, and openings around pipes
- Control rodent populations since mice and rats are a primary food source for many snake species
- Keep your yard trimmed so snakes lose the ground cover they rely on for safety
These changes address the reason snakes visit your property in the first place, rather than layering chemicals that the snakes will likely ignore anyway.