The liquid inside squishy toys is not a single standardized substance, and some formulations do contain chemicals that can be harmful, especially for young children who mouth, squeeze open, or inhale fumes from these products. The fill material ranges from mineral oil and silicone-based gels to water mixed with polymers, and the outer shells are typically soft plastics or rubber that may themselves leach chemicals. Research on tactile toys has flagged problems with boron levels, volatile organic compounds, bacterial contamination, and the physical danger of swallowed gel beads, so the short answer is that the risk depends on what is inside, how it gets out, and who is playing with it.
What Is Actually Inside Squishy Toys
The category “squishy toy” covers a wide range of products: gel-filled stress balls, water-bead sensory toys, foam-based slow-rise squishies, slime in sealed pouches, and rubbery water-wiggle tubes. The filling differs across types. Gel stress balls often contain a thick, clear liquid that is typically mineral oil, silicone oil, or a proprietary polymer gel. Water bead toys contain superabsorbent polymer spheres suspended in water. Slime-type products use polyvinyl alcohol or polyvinyl acetate cross-linked with a boron compound. Foam squishies may not have a liquid interior at all but are saturated with chemical residues from the manufacturing process. The outer casing is usually polyurethane, PVC, or thermoplastic rubber, and each of these materials brings its own concerns about plasticizers and volatile residues.
Because there is no universal “squishy toy liquid,” the toxicity question breaks down into several distinct risks. Some are chemical, some are biological, and some are purely physical. Each depends on what material the toy is made of, how old the toy is, and what a child does with it.
Boron in Slime and Gel Fillings
Boron is one of the best-documented hazards in this product category. Cross-linked slime and putty-type toys use borax or boric acid as the ingredient that gives the material its stretchy, gooey consistency. A 2021 study tested 127 slime products sold across five Asian cities and found that the average boron migration levels ranged from about 509 to 956 milligrams per kilogram of product, depending on the city. More than 70 percent of the products exceeded the European Union’s boron migration limit of 300 milligrams per kilogram for toys made with sticky material.1Journal of Exposure Science & Environmental Epidemiology. Children’s exposures to boron and biocides from slime products in Asian regions The study identified oral exposure as the most important route, meaning that children who put slime in or near their mouths absorb the most boron.
Boron at high doses irritates the digestive tract, and chronic exposure at elevated levels has been associated with reproductive and developmental effects in animal studies. For a child who plays with slime occasionally and washes their hands afterward, the risk is low. For a toddler who regularly mouths slime or plays with it for long stretches without handwashing, cumulative oral exposure can become significant. The fact that more than two-thirds of tested products exceeded the EU safety threshold suggests the problem is not confined to off-brand products from unregulated markets; it was widespread across every city sampled.
Volatile Chemicals That Off-Gas from Tactile Toys
Even if a child never breaks a squishy toy open, the toy can release chemicals into the air. A study evaluating volatile organic compound emissions from tactile toys found total VOC concentrations ranging from about 25 to 775 micrograms per cubic meter per gram of toy material. Among the hazardous residues detected were dimethylformamide and methylene chloride, both of which are process-related chemicals left over from manufacturing. In screening-level comparisons, these residues exceeded the U.S. Environmental Protection Agency’s reference concentrations for safe inhalation exposure.2Ecotoxicology and Environmental Safety. Quantitative evaluation of hazardous VOC emissions from tactile toys and investigation of emission drivers
Dimethylformamide is a solvent used in producing polyurethane foams, and methylene chloride is a common industrial solvent. Neither has any business being inhaled by a child. The concentrations varied widely across products, which means some toys are far worse than others, and there is no easy way for a parent to tell by looking at the packaging. A strong chemical smell when you first open a squishy toy is a rough indicator that VOC levels are high, but some harmful volatiles are nearly odorless. The practical takeaway is that new squishy toys benefit from being left out of their packaging in a ventilated space for a day or two before a child plays with them, which allows the most volatile residues to dissipate.
Phthalates and Plasticizer Migration
The soft, flexible shell of a squishy toy is typically made from PVC or a similar plastic that requires plasticizers to stay pliable. Phthalates are the most common class of plasticizer used in soft plastics, and they are not chemically bonded to the plastic matrix, which means they can migrate out over time, especially into saliva. Researchers have developed methods to measure how much phthalate migrates from plasticized toys into artificial saliva under conditions that simulate a child mouthing the object.3Journal of Chromatography B. Simultaneous GC–MS determination of eight phthalates in total and migrated portions of plasticized polymeric toys and childcare articles The concern is real enough that the EU and the United States both restrict certain phthalates in children’s toys, though enforcement and testing vary.
Phthalates are endocrine disruptors, meaning they can interfere with hormone signaling at sufficiently high exposure levels. For squishy toys specifically, the risk is highest when a child chews on the outer casing, because saliva accelerates migration. If the toy ruptures and the child swallows the inner liquid, the exposure route changes depending on what that liquid is. Mineral-oil-based fillings carry their own set of concerns, while water-based polymer gels present different ones. The shell and the filling should be thought of as separate exposure pathways.
Bacteria and Viruses in Water-Based Toy Fillings
Any toy that contains water or an aqueous gel creates a potential environment for microbial growth. An Italian survey of toys containing aqueous media found that nearly a quarter of the examined products failed to meet the limits set by European microbial safety guidelines. The most commonly exceeded limits were for aerobic bacteria, which were found in the majority of noncompliant samples. Pseudomonas aeruginosa, an opportunistic pathogen that can cause skin and ear infections, was detected in roughly 30 percent of the noncompliant toys. Other bacteria found included species of Stenotrophomonas, Burkholderia, and Sphingomonas.4Journal of Applied Microbiology. An Italian survey on the microbiological safety of toys containing aqueous media
The same study also tested a subset of samples for viruses and detected adenovirus genetic material in a quarter and enterovirus material in about one in ten, though neither showed active infectivity when cultured on cells.4Journal of Applied Microbiology. An Italian survey on the microbiological safety of toys containing aqueous media The presence of viral genomes without active infection is somewhat reassuring for that specific batch, but it does confirm that these toys are capable of harboring pathogens. A squishy toy that develops a small puncture or is played with by multiple children over weeks becomes a warm, moist reservoir where bacteria can thrive. If a child with a cut on their hand squeezes a contaminated toy, or if the liquid leaks onto a mucous membrane, the bacteria have a direct entry route.
This is an underappreciated risk because parents tend to think of squishy toys as sealed systems. In practice, the seals degrade. Small tears, compression fatigue, and rough play all compromise the casing, and the liquid inside does not stay sterile indefinitely, especially if the product contained no preservative to begin with.
When a Child Swallows the Contents
The most acute danger comes not from chemical toxicity but from what happens physically when certain toy contents are swallowed. Superabsorbent polymer beads, the kind found in water bead toys and some gel-filled squishies, are designed to expand dramatically when they absorb water. A literature review on superabsorbent polymer bead ingestion found that while most cases are initially considered harmless, the beads can swell inside the intestinal tract and cause bowel obstruction. Fatal outcomes have been reported.5PubMed. Bowel obstruction following ingestion of superabsorbent polymers beads: literature review The beads are small and colorful, which makes them look like candy to a toddler, and they may not show up well on standard X-rays because they are mostly water once expanded.
Mineral oil fillings present a different swallowing risk. If a child aspirates mineral oil (meaning it enters the airway rather than the stomach), it does not trigger the normal protective cough reflex the way water would, and it impairs the airway’s natural clearance mechanisms. This can lead to lipoid pneumonia, a form of lung inflammation caused by fat-based substances sitting in the lungs.6PubMed. Lipoid pneumonia: a silent complication of mineral oil aspiration Lipoid pneumonia can be insidious because the initial aspiration event may not produce dramatic symptoms, so a parent might not realize anything happened until the child develops a persistent cough or breathing difficulty days later.
Silicone-oil fillings, by contrast, are generally considered less toxic if swallowed in small amounts because medical-grade silicone is biologically inert. But “medical-grade” is the key qualifier. The silicone in a cheap squishy toy is not pharmaceutical-grade dimethicone; it may contain impurities or additives that make it less benign. Without knowing the specific formulation, which manufacturers rarely disclose in detail, assuming safety is a gamble.
How Regulation Handles These Products
Children’s toys are subject to safety standards in most countries, but squishy toys fall into a gray area. Standards like ASTM F963 in the United States and EN 71 in Europe set limits for heavy metals, certain phthalates, and mechanical hazards. A study of teethers, for example, found that concentrations of arsenic, cadmium, lead, and mercury did not exceed the safety limits set by ASTM F963 and EN 71.7Biological Trace Element Research. Infants’ Exposure to Toxic Trace Elements in Teethers That is good news for heavy metals, but it says nothing about boron levels, VOC off-gassing, microbial contamination, or the physical hazard of expandable polymer beads, none of which are consistently covered by the same standard.
The EU has a specific boron migration limit for sticky toy materials, but as the slime study showed, most products on the market exceed it.1Journal of Exposure Science & Environmental Epidemiology. Children’s exposures to boron and biocides from slime products in Asian regions In the United States, the Consumer Product Safety Commission has issued recalls and warnings for specific water bead products, but there is no blanket regulation requiring manufacturers to disclose what liquid is inside a squishy toy or to test it for microbial safety before sale. The regulatory framework was built for rigid plastic toys and has been slow to adapt to the wave of tactile, liquid-filled, and gel-based products that now dominate sensory play aisles.
This gap means parents are largely on their own when evaluating these toys. A product can carry a “non-toxic” label and still contain boron levels above EU limits, because “non-toxic” in the toy industry refers to acute poisoning thresholds, not to chronic low-level chemical exposure or microbial contamination. A toy that will not kill a child if they eat a piece of it can still expose them to endocrine disruptors, respiratory irritants, or opportunistic bacteria over months of regular play.
Practical Steps That Actually Help
Given the patchwork of risks, a few concrete habits reduce exposure without requiring you to throw every squishy toy in the trash:
- Air out new toys: Leave new squishy or foam toys unwrapped in a well-ventilated room for 24 to 48 hours before giving them to a child. This lets the most aggressive volatile residues dissipate.
- Inspect regularly: Check the casing for punctures, tears, or sticky residue on the surface. A leaking toy should be discarded, not patched.
- Enforce handwashing: The dominant exposure route for boron and plasticizers is hand-to-mouth transfer. Washing hands after play interrupts that route.
- Limit mouthing: Squishy toys are not teethers. If a child is young enough to mouth objects reflexively, they are too young for liquid-filled squishy toys.
- Avoid water beads for children under three: Superabsorbent polymer beads pose a serious physical hazard if swallowed. Many consumer safety agencies have issued specific warnings about these products for young children.
Why “Non-Toxic” on the Label Does Not Settle the Question
The phrase “non-toxic” on a toy label is one of the most misunderstood terms in consumer products. In the United States, the designation typically means the product has been evaluated by a toxicologist who determined it is unlikely to cause acute harm if a child ingests a small amount. It does not mean the product has been tested for chronic exposure, endocrine disruption, respiratory irritation, or microbial safety. A slime product with boron levels double the EU limit can legally carry a “non-toxic” label in a country without a boron-specific toy regulation. A squishy toy off-gassing methylene chloride at levels above EPA reference concentrations can be labeled “non-toxic” because the label refers to ingestion toxicity, not inhalation.2Ecotoxicology and Environmental Safety. Quantitative evaluation of hazardous VOC emissions from tactile toys and investigation of emission drivers
The label is not lying, exactly. It is just answering a much narrower question than the one parents are asking. When a parent reads “non-toxic,” they hear “safe.” What the label actually means is “probably won’t poison your child in a single exposure event.” Those are very different assurances, and the gap between them is where most of the real-world risk with squishy toys lives. Repeated skin contact, daily inhalation of residual solvents, cumulative oral exposure to boron through hand-to-mouth behavior, bacterial colonization of a slowly degrading gel reservoir: none of these scenarios are what the “non-toxic” evaluation was designed to address.
Until toy safety standards catch up with the chemistry and microbiology of these products, treating “non-toxic” as a floor rather than a ceiling is a reasonable approach. It means the toy probably will not cause an emergency from a single encounter. It does not mean you should stop paying attention to what is leaking, off-gassing, or growing inside it.