Is Gorilla Glue Toxic? Risks to Humans and Pets

Gorilla Glue is genuinely hazardous, though the specific dangers depend on which product in the Gorilla Glue lineup you’re dealing with and how you’re exposed. The original polyurethane formula contains an industrial chemical called MDI (methylene diphenyl diisocyanate) that can irritate the lungs, trigger asthma, and expand dramatically inside the stomach if swallowed. For pets, especially dogs, accidental ingestion is a veterinary emergency that often requires surgery. Even the brand’s cyanoacrylate-based “Super Glue” products carry risks that go beyond a simple skin bond, including a burn hazard most people have never heard of.

The Chemical That Makes Original Gorilla Glue Dangerous

Original Gorilla Glue is a polyurethane adhesive, and its key reactive ingredient is MDI. This chemical is what gives the glue its distinctive foaming, expanding behavior: when MDI contacts moisture, it undergoes a polymerization reaction that generates carbon dioxide gas, causing the glue to swell and harden into a rigid foam. That expansion is useful for filling gaps in woodworking, but it creates serious problems inside a living body. The same moisture in your mouth, throat, stomach, or lungs triggers the same reaction, and the resulting foam is difficult to dissolve or break apart once it has cured.

MDI itself, before it cures, is classified as a sensitizer and irritant. Animal studies have shown that inhaling MDI produces airflow limitation and an influx of inflammatory cells into the lungs.¹ Once the glue has fully cured and the MDI has reacted, the hardened polyurethane is largely inert. The danger window is during application and while the glue is still wet or off-gassing.

Breathing Gorilla Glue Fumes

Respiratory exposure is the risk that occupational health researchers have studied most thoroughly when it comes to diisocyanates like MDI. The fumes released during application are not as volatile as those from some other adhesives (MDI has a relatively low vapor pressure at room temperature), but in warm or poorly ventilated spaces, enough MDI can become airborne to cause trouble. Heating the glue or sanding partially cured glue generates more airborne particles and raises the risk considerably.

The most serious long-term consequence of MDI inhalation is occupational asthma. A large clinical follow-up of workers exposed to diisocyanates found that MDI was responsible for roughly four in ten new cases of diisocyanate-induced asthma diagnosed over a 16-year period.² Once someone becomes sensitized to MDI, even tiny subsequent exposures can provoke asthma attacks. Research on isocyanate exposure in workplace settings has confirmed that asthma can develop even at low concentrations, though higher exposure increases the risk.³

For someone using Gorilla Glue on a weekend project, the exposure is far lower than what factory workers experience daily. Still, the prudent approach is to work in a well-ventilated area or outdoors, avoid directly sniffing the bottle or freshly applied glue, and wear a respirator rated for organic vapors if you’re applying the product in an enclosed space or for extended periods. People with existing asthma or reactive airways should be especially cautious.

Skin and Eye Contact

Getting original Gorilla Glue on your skin is not a chemical burn scenario the way a strong acid would be, but it is a stubborn mechanical problem. The glue bonds tightly to skin and expands as it cures, and it cannot be washed off with soap and water. Acetone or mineral spirits can soften uncured polyurethane glue, but once it has hardened, you may need to wait for the outer layers of skin to naturally shed over several days. Prolonged or repeated skin contact with uncured MDI-containing products can also cause contact sensitization, meaning your skin may develop an allergic reaction to future exposures even in small amounts.

Eye exposure is more urgent. Any adhesive in the eye can cause the eyelids to stick together, and removing it risks damaging the cornea. Case reports of superglue eye injuries (which behave similarly to any fast-bonding adhesive splashed in the eye) show that separating stuck eyelids sometimes requires trimming eyelashes, and in at least one case, removing glue from the cornea caused a corneal abrasion that needed medical treatment and patching.⁴ If Gorilla Glue of any formulation gets in your eye, flush with warm water and seek medical attention promptly rather than trying to pry your eyelids apart at home.

Why Gorilla Glue Is a Veterinary Emergency for Dogs

Dogs are the animals most commonly affected by Gorilla Glue ingestion, largely because they’re attracted to the bottle and tend to chew it open. The consequences are severe. When the polyurethane adhesive hits the warm, moist, acidic environment of a dog’s stomach, the same expanding polymerization reaction takes over. The glue can swell to four to eight times its original volume within minutes, forming a hard, rigid mass that conforms to the shape of the stomach.⁵ As little as two ounces of glue has been reported to produce a foreign body large enough to cause obstruction.

A veterinary case series examining 22 dogs that ingested Gorilla Glue documented gastrointestinal foreign body formation and mechanical obstruction as consistent outcomes.⁶ The clinical signs to watch for typically appear within 12 hours and include loss of appetite, lethargy, vomiting, rapid breathing, and a visibly swollen or painful abdomen.⁵ If the mass blocks the stomach’s outlet or lodges in the esophagus, the situation can escalate to hemorrhage, ulceration, perforation of the stomach or esophageal lining, and death.

Treatment almost always means surgery. The expanded glue mass cannot be dissolved with any readily available agent, and it’s too large and rigid to pass on its own. Veterinarians typically perform a gastrotomy to remove the foreign body. If you suspect your dog has chewed into a bottle of polyurethane glue, don’t wait for symptoms to develop. Contact your veterinarian or an emergency animal hospital immediately. Do not induce vomiting at home, because the expanding mass can obstruct the esophagus or airway on the way back up, making the situation worse.

Cats, rabbits, and other household pets face the same theoretical risk, though reported cases are less common, likely because dogs are more prone to chewing through plastic containers. The safest approach for any pet household is to store polyurethane adhesives in a closed cabinet or toolbox that animals cannot access.

Gorilla Super Glue Is a Different Chemical Entirely

The Gorilla Glue brand now sells several products under the same name, and they are not all the same formula. The original brown-bottle polyurethane glue and the various Gorilla Super Glue products (clear bottles, gel formulas) use completely different chemistry. Gorilla Super Glue is a cyanoacrylate adhesive, the same class of chemical found in Krazy Glue and most “instant” adhesives. Cyanoacrylate and polyurethane adhesives create different hazards, and mixing them up can lead to the wrong first-aid response.

Cyanoacrylate adhesives are generally less toxic if accidentally swallowed in small amounts. A large review of cyanoacrylate exposures reported to a poison control system found 893 patients over a multi-year period. The vast majority of exposures were unintentional, and about three-quarters of patients were managed at home without needing to visit a healthcare facility. Effects were classified as none in about a third of cases, minor in most of the rest, and moderate in a small fraction. No major effects or deaths were reported.⁷ The most common routes of exposure were ingestion, eye contact, and skin bonding, often in children. The median patient age was 11 years, underscoring how frequently kids get into these products.

That relatively reassuring profile does not mean cyanoacrylate glues are harmless. They bond skin instantly and can seal eyelids shut. Ingestion in larger amounts can glue tissues together in the mouth or throat. And cyanoacrylate produces irritating fumes (the familiar stinging-eye sensation when you open a tube of superglue), which can bother people with sensitive airways. But the expanding-foam nightmare that makes original Gorilla Glue so dangerous when swallowed does not happen with the Super Glue version, because cyanoacrylate polymerizes into a thin, hard film rather than an expanding mass.

The Cotton and Cyanoacrylate Burn Hazard

One risk associated with cyanoacrylate glues that catches most people off guard is the violent reaction between superglue and cotton. When cyanoacrylate contacts cotton fibers (or other cellulose-rich fabrics like denim), it triggers a rapid exothermic polymerization that generates enough heat to cause a full-thickness burn on the skin underneath.⁸ The temperatures reached during this reaction can cause significant thermal injury, and case reports have documented children requiring burn treatment after superglue dripped onto cotton clothing.⁹

This means you should never wipe up spilled Gorilla Super Glue (or any superglue) with a cotton rag, and you should keep it away from cotton clothing while working. If superglue soaks into a cotton garment you’re wearing, remove the garment quickly rather than trying to wipe it off. The heat builds rapidly and can burn before you realize what’s happening. Synthetic fabrics like polyester and nylon do not trigger the same reaction.

What to Do If Someone Is Exposed

The right response depends on which product was involved and how the exposure happened. Here are the most common scenarios:

Skin bonding: For cyanoacrylate (Gorilla Super Glue), soak the bonded area in warm soapy water and gently peel or roll the skin apart. Acetone-based nail polish remover can dissolve the bond but should not be used near the eyes, mouth, or on young children’s skin. For polyurethane (original Gorilla Glue), try wiping uncured glue off with acetone or mineral spirits before it sets. Once cured, it has to wear off naturally.
Eye contact: Flush with warm water and do not force eyelids open if they are stuck together. Go to an emergency room or ophthalmologist. Pulling stuck lids apart can damage the cornea.
Ingestion of original Gorilla Glue: Call Poison Control (1-800-222-1222 in the United States) or go to an emergency room immediately. The expanding foam reaction means the window for intervention is short. Do not induce vomiting.
Ingestion of cyanoacrylate glue: Small amounts typically cause only minor effects, but call Poison Control for guidance. If the glue has bonded lips or tissues inside the mouth, do not try to pull them apart forcefully.
Fume inhalation: Move to fresh air. If you develop wheezing, chest tightness, or difficulty breathing, seek medical care. Mention that the product contains MDI if you were using the polyurethane formula, as this information helps clinicians choose the right treatment.
Pet ingestion: Contact your veterinarian or an emergency animal hospital immediately. For polyurethane glue ingestion, surgery is the most likely outcome and the sooner the animal is evaluated, the better.

Occupational Exposure and Long-Term Use

Most of the serious human health data on MDI and other diisocyanates comes from occupational settings, where workers handle these chemicals daily for years. Beyond asthma, chronic exposure to volatile organic solvents used in adhesive manufacturing has been linked to neurotoxic effects. A study of workers in a plant producing adhesive materials found that prolonged low-level exposure to solvents (primarily n-hexane and toluene, which are found in various adhesive formulations though not specifically in Gorilla Glue) was associated with impaired balance control, reflecting damage to the central nervous system structures involved in postural regulation.¹⁰

For the average person using Gorilla Glue a few times a year for household repairs, the occupational literature is not directly applicable. You’re not breathing MDI fumes for eight hours a day, five days a week. But the research establishes that these chemicals are not benign, and it reinforces why ventilation matters even for short projects. If you find yourself using polyurethane adhesives frequently for a hobby like woodworking or model-building, investing in a proper respirator and ensuring good airflow in your workspace is worthwhile. The sensitization risk with MDI is particularly worth taking seriously: once your immune system decides MDI is a threat, the reaction doesn’t require much chemical to trigger, and the resulting asthma can persist even after exposure stops.

Intentional Misuse and the TikTok Incident

In early 2021, a widely publicized case brought Gorilla Glue into mainstream conversation when a woman used Gorilla Glue Spray (a polyurethane-based adhesive spray) as a hair styling product. The adhesive bonded to her hair and scalp so thoroughly that she required medical treatment to remove it. While extreme, this case illustrates a broader pattern: adhesive products are sometimes used in ways the manufacturer never intended, and the consequences can be severe precisely because these chemicals are designed to form permanent bonds.

The poison control data on cyanoacrylate exposures confirms that intentional misuse, while uncommon, does happen. Out of 893 cyanoacrylate exposure cases reviewed, a small number were classified as intentional, including attempts to seal bleeding cuts and pranks involving gluing someone’s eyes shut.⁷ The takeaway is straightforward: adhesives should only be used on the materials they’re intended for. Human skin, hair, and mucous membranes are not among them.

Storing Gorilla Glue Safely

Proper storage reduces the most common exposure scenarios, particularly for children and pets. Original Gorilla Glue bottles are brown plastic with a flip-cap that dogs find easy to chew through. Cyanoacrylate tubes are small and easily mistaken for eye drops or lip balm, which accounts for many of the accidental exposures in children. A few practices make a meaningful difference:

Store out of reach: A locked toolbox, high shelf, or latched cabinet keeps products away from both children and pets. The median age of cyanoacrylate exposure patients being 11 years old suggests that “out of reach” needs to account for school-age kids, not just toddlers.
Reseal tightly: Polyurethane glue cures when exposed to moisture in the air, so a poorly sealed bottle will slowly harden and may crack open. A cracked bottle leaking glue in a drawer is an invitation for a curious dog.
Don’t decant: Transferring glue into unmarked containers creates confusion. Keep products in their original packaging with warning labels intact.
Dispose of old product carefully: Partially used bottles of polyurethane glue that have started to cure internally can build up pressure from the CO2 generated during the reaction. Open old bottles cautiously, pointed away from your face.

For households with dogs that have a history of chewing into containers, it’s worth treating polyurethane adhesives with the same level of caution you’d give to medications or cleaning chemicals. The veterinary literature makes clear that even a small amount of ingested glue can form a mass large enough to require surgical removal, and the speed at which the reaction occurs leaves very little time for the glue to pass through the digestive system before it solidifies.