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I grew up reading about materials that shaped the story of modern industry. Isobutylene-isoprene copolymer, or butyl rubber as people often call it, came about in the late 1930s. It wasn't a typical academic invention but a response to wartime scarcity; the world looked for substitutes that could do what natural rubber did without relying on tropical climates. Chemists discovered that combining isobutylene with tiny amounts of isoprene delivered something magic—airtight, flexible, weather-resistant, and immune to oxidation. By World War II, mass production was in full swing. For those who trace the story of innovation, butyl rubber carries the lesson: necessity drives new materials just as much as curiosity does.
You can find this polymer wherever stretch, air-tightness, and resistance to chemicals cross paths. Tires rely on butyl rubber because it holds air better and ages slower than most synthetic alternatives. Pharmaceutical stoppers, protective clothing, adhesives, even sports-ball bladders—all owe their performance to this family of copolymers. I’ve seen whole industries depend on the reliability of butyl rubber’s structure, especially in products that demand low permeability and chemical inertness. In everyday products, it's the unsung workhorse that's easy to overlook, and yet its absence would change how entire sectors function.
Isobutylene-isoprene copolymer shows a unique mix of flexibility, impermeability, and durability. At the molecular level, the saturated nature of the backbone puts up a shield against oxygen, ozone, and chemicals; it hardly cracks under UV exposure and stays elastic down to frigid temperatures. The copolymer picks up low gas and moisture permeability, which gives it a leg up over natural and other synthetic rubbers. Its density clocks in around 0.92 g/cm³, and glass transition happens near -70°C. Solubility trends matter: it dissolves in hydrocarbon solvents but shrugs off polar ones like water and alcohol. These properties underline why tire innertubes and pharmaceutical closures trust butyl rubber's makeup—they're counting on barrier performance day in, day out.
In my lab days, product sheets for butyl rubber never stopped at basic density or viscosity. Technical specs covered molecular weight, Mooney viscosity, degree of unsaturation, and vulcanizate strength. Manufacturers need each batch to remain consistent, and labeling involves trade names, polymer grade, cure system compatibility, and batch lot data. Without clear technical labeling, processing plants face unpredictable end-use properties. Quality assurance teams pore over these details, knowing full well that a mislabel could mean tire recalls or pharmaceutical contamination scares.
The old school process that started in wartime Cincinnati now echoes in modern reactors worldwide: low-temperature cationic polymerization. Large tanks hold isobutylene and a small percent of isoprene, with aluminum chloride as a catalyst, with methyl chloride as a medium, all kept shivering cold, often below -90 °C. The result is a chain with mainly isobutylene units and occasional isoprene, which opens the door for cross-linking when it comes time to extend durability. I’ve heard plant engineers complain about the hazards—the cold, the handling of toxic precursors—but they stick with it, because tweaks to this process change the curing and end-use profile.
On its own, butyl rubber gives you basic rubbery properties, but chemical modifications open whole new application worlds. Halogenation (adding chlorine or bromine) lets the rubber cure faster and tougher with other agents, which is why you see bromobutyl or chlorobutyl names on advanced products. What starts as a simple copolymer turns into a tailored material for applications such as pharmaceutical seals—where leaching and contamination set strict limits. Grafting side groups or blending with fillers and antioxidants lets users tune performance, cost, and process ability. The chemists working on these upgrades live by the mantra: push properties, safeguard health, and respect regulatory limits.
It’s easy to get lost in the maze of names. Butyl rubber, PIBI (polyisobutylene isoprene), or even trade names like Exxon’s Butyl® or Lanxess’ X_Butyl—all point to this single class. Sometimes the rubber gets tagged by its curing approach: regular butyl, bromobutyl, or chlorobutyl. For buyers, these labels mean different performance, different price, and different regulatory hurdles. In my own experience with material sourcing, miss-ordering by relying on a vague trade name means blown deadlines and angry phone calls, because not every isobutylene-isoprene copolymer is fit for every job.
Every time I’ve worked near facilities handling this material, strict rules governed safety. Butyl rubber itself behaves safely in final products. The risks cluster around the production phase: low temperatures, reactive catalysts, toxic monomers. Plants follow international and national safety standards like OSHA, REACH, and ISO, taking chemical exposure, fire risk, and worker safety to heart. Finished goods—be it medical closures or food packaging—have to pass rigorous migration and extractable tests. It’s not just about satisfying checklists but about protecting end users, often hospital patients or kids using sporting goods, from tiny risks magnified by mass use.
If you want to appreciate the reach of this copolymer, look at your car tires. Air loss from innertubes goes way down with butyl rubber. The same property saves lives in gas masks and gloves, blocking toxic vapors far better than natural rubber. Stoppers in injection vials protect drugs from moisture and contamination, key in critical care settings. Construction sector uses the material in sealants and membranes, where leak-proofing and weather resistance bring down repair costs. Consumer products—from adhesives and chewing gum base to electrical insulation—gather value from the predictability of butyl rubber’s traits.
Labs and companies spend time and money searching for better grades, cleaner processes, and smarter blends. During my visits to industry conferences, the big guns always showcased improved modifiers, curatives, and blending agents. Research groups probe new catalyst systems, seeking higher efficiency and greener production. University labs test bio-based isobutylene, studying ways to lower the environmental footprint without changing performance. Analytical chemists measure trace extractables in medical closures, working to stay ahead of tightening pharma standards. Everyone in the field seems locked in an arms race: higher purity, lower footprint, and product performance that adapts to new end-use challenges.
Health and safety studies often draw me in, especially when they tip the balance for industry acceptance. Finished butyl rubber runs chemically stable, doesn’t leach much, and sits near the top for safety in skin and respiratory contact. Regulatory agencies focus on phthalates, nitrosamines, and extraction profiles for medical and food use. Regular monitoring of monomer residues, especially isoprene, protects against mutagenic risk—something no one wants to gamble with. Toxicity research keeps improving: worker exposure in plants, atmospheric releases near production clusters, and long-term safety studies on packaging materials. Companies bet on rigorous documentation and testing because the liability of missing contamination harms both public trust and market access.
Based on where the industry aims, this copolymer won’t fade out anytime soon. Tires will still need air-tightness and fuel efficiency, so demand tracks with car and truck production. Green chemistry offers real hope: bio-based synthesis, solvent recovery, and recycling promise to reduce environmental headaches. My discussions with younger researchers suggest new blends and nano-composites could unlock biomedical and electronics applications—areas hungry for elasticity and chemical resistance with better purity and sustainability. Global regulations tighten every year, so companies willing to innovate on cleaner processes and safer chemical profiles will find markets ready to reward them. The next chapter in butyl rubber’s story probably means cleaner, smarter, and more specialized uses, not just more of the same.
Isobutylene-isoprene copolymer, often called butyl rubber, has become a behind-the-scenes workhorse in modern industries. Its mix of stretch, chemical stability, and resistance to heat explains why it often gets picked for tasks where regular rubber, natural or synthetic, just won’t cut it. People in manufacturing count on its air retention, softness, and ability to handle ozone or weather without breaking down.
Butyl rubber hits the road, literally, as a main ingredient in tire inner liners. Tire makers turn to this copolymer when they want a product that won’t let air seep out over time, keeping rides safer and drivers out of the shop. Manufacturers also use it to improve sealing in car windows and doors, helping to block noise and water. Inside vehicles, it finds its way into hoses and belts, where resistance to aging and chemicals matters. This kind of reliability can mean the difference between a regular commute and a sudden roadside mishap.
Anyone who’s ever popped the top on a medicine vial has dealt with butyl rubber. It seals injectable medicines because it holds up under sterilization—the high heat or gamma radiation—without letting fragments break loose. Its low permeability comes in handy for keeping drugs pure, infection-free, and safe while on the shelf. Medical stoppers, plungers for syringes, and seals for IV lines all rely on this polymer’s specialty mix of sterility and flexibility. Using a material like this lowers the chance of contamination, protects patients, and eases regulatory headaches.
Manufacturers lean on butyl rubber in situations where aging, weather, or harsh chemicals chew through lesser plastics. Roofing and waterproofing tapes made from this material shrug off sun and rain for years. In cable insulation, it resists electrical leaks and keeps connections dry and safe. Factories use it as a barrier in chemical tanks or linings in pipelines, knowing that it blocks nearly anything trying to get through—acids, gases, or plain water.
Sports gear takes a beating, so butyl rubber backs up inner tubes for balls and bikes. It keeps the air where it should be, whether you’re pedaling or dribbling down a court. On construction sites, builders trust butyl copolymer to help seal windows and roofs. It stays flexible over seasons of sun or frost, keeping leaks out and energy bills down. Even common consumer products like adhesives, tapes, and protective gloves benefit from its durability and stretch.
The business end of all this comes down to safety, reliability, and cost. Using isobutylene-isoprene copolymer means fewer product failures, longer lifespans, and less waste—a win for companies and the planet. Investing in better recycling systems for this copolymer and researching plant-based alternatives could help cut the environmental footprint, answering growing calls for sustainable industry solutions. It pays off for everyone: cleaner water, safer roads, and fewer headaches for workers and regular folks alike.
Isobutylene-isoprene copolymer shows up in a lot of beauty and personal care products, especially things like lip gloss, mascaras, and skin creams. It makes textures smoother, keeps ingredients locked in, and helps the product stay put longer through hot days or a bit of rain. People with skin sensitivities or allergies start to wonder about anything with such a chemical-sounding name. As someone who once spent years tracking down allergic triggers in skin care, I make it a habit to learn what is behind the label, not just what it promises.
Most people know isobutylene-isoprene copolymer as a synthetic rubber, created from two types of molecules, sometimes named butyl rubber in technical lists. This polymer features in popular waterproof formulas—often delivering that coveted no-smudge result that the beauty world loves. Its job doesn’t sound glamorous, but for makeup to resist humidity and sweat, something needs to keep the product together without crumbling into flakes or stinging eyes.
The safety talk usually begins with the basics: does this substance pass muster with skin care authorities? The US Food & Drug Administration (FDA) and European regulators allow it in cosmetics as long as manufacturers stick to purity guidelines. Research and cosmetic safety panels, such as the Cosmetic Ingredient Review (CIR), have found little public evidence of irritation or long-term health harms at the concentrations used in typical beauty items. Most allergy reports focus on the fragrance mixes and preservatives in the same jar, not this copolymer.
Synthetic polymers, especially those from petroleum, sometimes make people uneasy. Isobutylene-isoprene copolymer is no exception. Some worry about its impact beyond the beauty aisle. It does not break down easily in the environment, leading to concerns over accumulation and microplastics—tiny bits that can end up in rivers and oceans. For anyone passionate about green or zero-waste lifestyles, petroleum-based plastics in personal care products do seem out of step.
Most dermatologists report little risk for people without a latex allergy. I’ve seen this reflected in community forums and at my own dermatologist’s office. Copolymers don’t stick out as a common cause of skin problems. Out of hundreds of products using this ingredient, only rare allergy cases appear in the literature. If someone already struggles with allergic reactions, running a patch test makes sense.
For shoppers who want both performance and peace of mind, some brands now offer “clean beauty” formulations that avoid petroleum-derived ingredients. Reading labels, checking for third-party certifications, and reaching out to brands about sourcing offer practical steps for reducing exposure. For those who need waterproof makeup, the performance trade-off still weighs on the final choice. But anyone can scan the ingredient list, ask about allergy testing, and decide based on personal needs and environmental values.
Researchers continue to look for plant-based or biodegradable substitutes that can match the function of these copolymers. Some of these alternatives, still in development, show promise for people wanting fewer synthetics in daily routines.
Isobutylene-isoprene copolymer, often called butyl rubber, shows up quietly in lots of places—think car tires, shoe soles, basketballs, even the lining of medicine bottles. Most folks won’t ever hear its full name, but this polymer shapes modern life more than we notice. What makes it special isn’t only how tough it is or how it stretches; it’s the blend of physical and chemical traits that help it outperform natural rubbers in tricky conditions.
Flexibility matters. Melt butyl rubber and you’ll see that it flows steadily, a sign of its excellent processability during manufacturing. Finished products stay elastic—even at low temperatures—because the material has a very low glass transition temperature, around -70°C. So rubber liners in a freezer truck flex and snap back to shape instead of turning brittle or cracking.
Poke or squeeze a block of this copolymer and you’re dealing with a dense, solid chunk—most grades hover between 0.91 to 0.92 grams per cubic centimeter. In practice, this delivers enough substance for car tires that won’t give out under pressure. Drop those tires into a drum of water, and you’ll notice no bubbles—water vapor has a hard time getting through. This property comes from the tight, stable arrangement of the polymer chains, which block moisture and air better than most other rubbers.
Butyl rubber laughs in the face of most chemicals. Oils, ozone, UV rays, and aggressive solvents all run off its surface because of the stable, saturated backbone in its structure. In the courses I took on polymer science, this trait came up again and again: tire liners don’t just last because of strength—they resist the invisible attack of oxygen and light that’d make alternatives fail long before their time.
As for reactivity, isobutylene-isoprene copolymer keeps itself to itself. That makes it great in pharmaceutical closures; if you’re storing medication, you don’t want the seal to react with your drug. Only strong acids or oxidizers break it down easily. Its low level of unsaturation limits unwanted cross-reactions, so manufacturers can predict performance over decades, not just a few years.
Sealing in freshness, insulating from weather, or lining tanks for aromatic chemicals becomes possible thanks to the toughness and tight structure of this copolymer. The impermeability to gases—about 10 times better than natural rubber—keeps car tires inflated for months and protects sensitive products inside food and medicine packaging. I’ve seen how a small rubber gasket with these properties stopped a months-long headache in a water treatment project; switching from natural rubber to this copolymer ended the leaks completely.
By combining strength, flexibility, and chemical resistance, isobutylene-isoprene copolymer keeps costs down through fewer replacements and repairs. Manufacturers benefit from predictable long-term performance. For folks worried about toxic substances, the stability also means less chance of leachable contaminants reaching water or food.
Every material has limits. Isobutylene-isoprene copolymer doesn’t handle concentrated hydrocarbons or extreme heat above 120°C. Newer applications always push those boundaries—sometimes blends with other materials, or new crosslinkers, offer ways to improve heat resistance without losing flexibility or the impressive barrier properties. Research points toward recycling and alternative feedstocks for greener production methods, too. Greater transparency in measures of chemical migration, especially for food and pharma uses, stands out as a must. Advances in analytical chemistry let us track these migrations down to the parts-per-billion range, building trust along the supply chain.
Ongoing collaboration between chemists, engineers, and end users holds promise for stronger, safer, and more sustainable rubber materials. Each new product brings a chance to learn from both lab tests and real-world experiences, ensuring future generations of materials meet rising expectations in safety and reliability.
Walk down the drugstore aisle and you’ll notice a pile of everyday products promising all kinds of perks. The common factor in some of these—baby bottle nipples, rubber stoppers, the seal in a medicine vial—is Isobutylene-Isoprene Copolymer, often recognized by many as butyl rubber. This tough, squishy polymer makes sure baby bottles don’t leak, medicine stays sealed, and tires grip the road reliably. Engineers and manufacturers prefer it because it stands strong against heat, gases, and moisture, and doesn’t get brittle for years.
Isobutylene-Isoprene Copolymer’s biggest selling point is its stubbornness in tough environments. Strong chemical bonds pack its molecular structure, blocking oxygen, water, and sunlight from breaking it down. That’s a real asset in hospitals or on the highway, but it poses a challenge for nature. Living things—bacteria, fungi, even the sun’s energy—struggle to break apart those chemical links.
I once worked for a local recycling campaign in a busy city. Sorting through bins, I saw just how much rubber-based packaging people tossed out. Most ended up in landfills, where oxygen is scarce and bacteria hardly survive. Science backs this up. Research in Waste Management & Research showed that butyl-based rubbers hold their shape after years of burial, far longer than natural rubber or plant-based plastics.
Statistics tell their own story. According to a 2022 report by PlasticsEurope, synthetic rubbers make up a significant slice of global plastic waste. Isobutylene-Isoprene Copolymer accounts for a decent chunk in tire and medical markets. These products stick around for decades, not months. Landfill operators measure decay in timeframes of centuries, not years.
Laboratory tests tried to speed things up with heat, UV rays, and experimental enzymes, but only surface cracks appeared. No full breakdown or composting occurred. Compostable plastics, like polylactic acid (PLA), fall apart in under a year with the right conditions, but butyl rubber stands firm.
Younger generations notice this lasting impact. Social media is filled with calls for less plastic waste, and governments are making moves, too. France and Germany introduced fees for packaging materials that stick around too long. China’s limits on tire disposal pushed automakers to research “greener” alternatives. Even in conversation with friends who grew up in rural towns, dumping old rubber boots in the woods is no longer seen as harmless. People want real answers.
No magic bullet exists right now, but there’s movement. Researchers at MIT and in Europe test plant-derived fillers and additives that help bacteria attack rubber’s tough bonds. Some companies experiment with recycling used butyl rubber into industrial flooring or playground mats. More promising, investment is rising in biobased polymers, like natural rubber blends, that can do much of the same work but eventually break down in soil or water.
In my own family, switching out certain plastics for glass or silicone helped cut down on stubborn waste. Cities that invest in recycling plants for rubber and plastics see lower landfill rates and better air quality. It’s clear that single-use plastics with no end-of-life plan shouldn’t be the norm. Consumers and industry leaders both drive this change, whether by swapping out products, innovating materials, or demanding stricter policies.
Isobutylene-Isoprene Copolymer brings safety and reliability, but its resistance to breakdown creates a hidden cost for the environment. Until more biodegradable options arrive, reducing use, improving recycling, and investing in new chemistry offer practical paths forward.
Isobutylene-isoprene copolymer turns up in plenty of everyday items. People find it inside adhesive bandages, sealants, and even baby bottles. The chemical mix makes rubber that’s flexible and resistant to many chemicals. It keeps things sealed tight and holds up against wear. The stuff gets picked for products that touch skin, food, and even the insides of medical devices. Doctors and industry leaders like this copolymer since it rarely picks up dust or moisture and tends not to break down easily.
Most people hearing about chemicals in products wonder if touching or using them can spark allergies. That worry doesn’t come out of nowhere. Latex allergies can cause hives, rashes, or even dangerous trouble with breathing. Latex’s protein content triggers most reactions, and some assume all rubber-like products can do the same. Isobutylene-isoprene copolymer stands apart because it doesn’t have those proteins. It’s a synthetic rubber, made in factories, not tapped from trees like latex.
Allergists and medical researchers have looked for patterns among folks who use products containing isobutylene-isoprene copolymer. Studies published by the American Contact Dermatitis Society show very few, if any, cases where this copolymer sparked allergic skin reactions. The Material Safety Data Sheets and resources like the FDA point out that compared to natural rubber latex, this material is a low-risk choice for sensitive people. That’s why you’ll see it listed as a main component in “latex-free” products.
My own experience with patients in healthcare backs this up. Children and adults with severe latex allergies often do just fine having wounds dressed with bandages containing this copolymer. Parents with anxious kids ask about the adhesive strips and hospital gloves, and medical professionals steer them toward products that use this type of synthetic rubber.
No material waits entirely free of risk. Rare people might react, not to the copolymer itself, but to impurities left over in the manufacturing process, or to additives blended during production. Patch testing on people with a history of contact allergies usually returns negative with this copolymer, but outliers exist. Anyone facing red, itchy skin or swelling around these products should see an allergist for patch testing. Also, regulatory agencies keep watch, updating safety assessments if reports show problems.
Reading packaging still helps. Most makers of medical and personal care products clearly state “latex-free” if they use isobutylene-isoprene copolymer. Picking those products makes sense for schools and clinics that aim to keep allergic reactions to a minimum. Manufacturers stand to earn trust by listing ingredients openly and adopting stricter purity checks. Health professionals do well to stay updated on material recalls and alerts from groups like the CDC or FDA.
This issue matters. Allergies put lives at risk and shake up daily routines for families. Anything that lowers that risk deserves attention and clear information. Products built around isobutylene-isoprene copolymer tend to make life easier for people with sensitivities, but asking questions and reporting unusual symptoms builds a safer world for everyone.
| Names | |
| Preferred IUPAC name | Poly(1-butene-co-2-methylprop-1-ene) |
| Other names |
Butyl Rubber Isobutene-Isoprene Rubber Butyl Polysobutylene IIR |
| Pronunciation | /ˌaɪ.səˈbjuː.tɪˌliːn ˌaɪˈsɒ.priːn ˈkəʊ.pɒl.ɪ.mər/ |
| Preferred IUPAC name | poly[(1-methylethylene)-co-(2-methyl-1,3-butadiene)] |
| Other names |
Butyl Rubber Isobutene-Isoprene Rubber Butyl Polymers |
| Pronunciation | /ˌaɪsəˈbjuːtəˌliːn ˌaɪˈsɒpriːn kəˈpɒlɪmər/ |
| Identifiers | |
| CAS Number | 9010-85-9 |
| Beilstein Reference | 3850045 |
| ChEBI | CHEBI:53487 |
| ChEMBL | CHEMBL3331324 |
| ChemSpider | 10092410 |
| DrugBank | DB09555 |
| ECHA InfoCard | 100.127.324 |
| EC Number | 232-945-1 |
| Gmelin Reference | 46318 |
| KEGG | C22137 |
| MeSH | D007533 |
| PubChem CID | 11910706 |
| RTECS number | NI0525000 |
| UNII | RXY5T8J6XH |
| UN number | UN 1866 |
| CompTox Dashboard (EPA) | DTXSID7020182 |
| CAS Number | 9010-85-9 |
| Beilstein Reference | 1461135 |
| ChEBI | CHEBI:53487 |
| ChEMBL | CHEMBL1742871 |
| ChemSpider | 21259746 |
| DrugBank | DB11097 |
| ECHA InfoCard | ECHA InfoCard: 100.112.998 |
| EC Number | 232-945-6 |
| Gmelin Reference | 14729 |
| KEGG | C18683 |
| MeSH | D007651 |
| PubChem CID | 12405 |
| RTECS number | WHX9696DU9 |
| UNII | 6T7U8O43UU |
| UN number | Not regulated |
| CompTox Dashboard (EPA) | DTXSID9020937 |
| Properties | |
| Chemical formula | C8H14 |
| Molar mass | 68000.0 g/mol |
| Appearance | White or light yellow transparent solid or semi-solid |
| Odor | Odorless |
| Density | 0.92 g/cm³ |
| Solubility in water | insoluble |
| log P | 0.11 |
| Vapor pressure | Negligible |
| Basicity (pKb) | >12. |
| Magnetic susceptibility (χ) | −9.94×10⁻⁶ |
| Refractive index (nD) | 1.516 |
| Viscosity | 800 - 11,000 mPa·s (at 100°C) |
| Dipole moment | 0.13 D |
| Chemical formula | (C4H8)x(C5H8)y |
| Molar mass | 68000.00000 g/mol |
| Appearance | White to light yellow elastic solid |
| Odor | Odorless |
| Density | 0.92 g/cm³ |
| Solubility in water | insoluble |
| log P | >6 |
| Vapor pressure | Negligible |
| Acidity (pKa) | >40 (estimated) |
| Magnetic susceptibility (χ) | -11.9e-6 cm³/mol |
| Refractive index (nD) | 1.515 |
| Viscosity | 250-350 mPa.s (100°C) |
| Dipole moment | 1.32 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 153 J mol⁻¹ K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | -59.9 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | -4529 kJ/mol |
| Std molar entropy (S⦵298) | 146.6 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | -68.1 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | -45600 kJ/mol |
| Pharmacology | |
| ATC code | V09FX10 |
| ATC code | V09FX10 |
| Hazards | |
| GHS labelling | GHS07 |
| Pictograms | GHS07,GHS09 |
| NFPA 704 (fire diamond) | 1-1-0 |
| Flash point | 260 °C (500 °F) (approximate) |
| Autoignition temperature | 420°C (788°F) |
| LD50 (median dose) | > 9900 mg/kg (rat, oral) |
| NIOSH | NQ6475000 |
| PEL (Permissible) | PEL (Permissible) of Isobutylene-Isoprene Copolymer: Not established |
| REL (Recommended) | 10 mg/m³ |
| GHS labelling | GHS02, GHS07 |
| Pictograms | GHS07,GHS09 |
| Signal word | No signal word |
| Hazard statements | No hazard statement. |
| NFPA 704 (fire diamond) | 1-1-0 |
| Autoignition temperature | 443°C |
| NIOSH | RN9083 |
| REL (Recommended) | 40 mg/m³ |
| Related compounds | |
| Related compounds |
Polyisobutylene Butyl rubber Halobutyl rubber Polyisoprene Styrene-butadiene rubber |
| Related compounds |
Butyl rubber Isobutylene Isoprene Polyisobutylene Halobutyl rubber |
