Back in the mid-1960s, chemists at Boots Co. in England started searching for a new antimicrobial to tackle stubborn bacteria in pharmaceuticals, personal care products, and industrial water systems. Their research led them to 2-bromo-2-nitropropane-1,3-diol, which they called bronopol. It didn’t take long before companies across Europe and North America began bringing bronopol to their lines thanks to its punch against bacteria and fungi, giving products a longer shelf life and solving big contamination headaches in everything from cosmetics to cooling systems. The growth continued through the 1970s and ‘80s, as the chemical earned a reputation for keeping bacteria under control without a strong odor or staining tendencies that plagued similar preservatives.
Bronopol shows up in small, white or off-white crystalline form, usually sold as a fine powder or granular solid for manufacturing, although it can also arrive dissolved into ready-to-use liquid blends. It gets shipped in well-sealed drums and lined cartons to keep moisture away, because contact with water shortens its shelf life and causes clumping. In practice, bronopol preserves shampoos, creams, hand soaps, and household cleaners, and also keeps bacteria at bay in industrial water used for paper making and oil recovery. Even though plenty of businesses have tried to switch to more “natural” alternatives under consumer pressure, bronopol still fills a unique spot in product formulations that need reliable microbial control with limited impact on texture and scent.
Bronopol’s chemical structure, C3H6BrNO4, packs a bromine atom and a nitro group onto a propanediol backbone. It melts at around 130 °C and dissolves quite well in water, making it easy to mix into most liquid systems. Because it has both oxidizing and halogenated groups, it doesn’t break down easily at room temperature, though it reacts with reducing agents or sunlight, which can set off a color change from white to yellow or brown. Its strong activity against bacteria comes from the way it messes with cellular enzymes, especially in water with a neutral or slightly acidic pH.
Standards for bronopol vary a bit from country to country, though most manufacturers guarantee a minimum purity above 99%, with tight controls to limit free bromine, moisture, and any unknown impurities. Safety data sheets spell out precautions for handling, since high concentrations may irritate skin and eyes, and dust inhalation can kick up respiratory symptoms. Regulations across the United States and European Union require clear labeling if bronopol sits among other preservatives in cosmetics or cleaning agents, since certain people react to it even at low levels. All professional handling setups use gloves, goggles, and well-ventilated spaces to cut down exposure risk and chemical breakdown.
Bronopol builds from a straightforward synthetic reaction. Starting with nitromethane and formaldehyde in basic conditions, manufacturers add in hydrobromic acid to introduce the bromine atom. The reaction gets carried out in stainless steel reactors that resist acid corrosion, keeping the temperature in check to avoid unwanted byproducts. After cooling and filtration, the crude bronopol gets crystallized and dried, leaving behind a stable chemical fit for shipment and blending into commercial goods. Every batch goes through thorough testing for purity, moisture content, and active ingredient strength before it gets put into a bag or bottle.
This chemical stands out because it breaks down efficiently in the presence of reducing agents, alkaline conditions, or sunlight—meaning it’s quite stable in bottles and tanks, but begins decomposing rapidly as soon as it enters an environment with organic matter or certain metals. Some research labs have tested tweaks to the structure—like swapping bromine for chlorine or switching out the nitro group—to try and make bronopol derivatives that keep its power but reduce its drawbacks, like nitrosamine formation. So far, none of these alternatives have hit the same balance of stability and antimicrobial effect as the original molecule, but the search goes on, especially for use in areas with stricter environmental demands.
Across different industries and countries, bronopol can appear under several names: 2-bromo-2-nitro-1,3-propanediol, BIS (short for bromo-nitrodiol), BNPD, or its trade names such as Myacide, Bronosol, and Onyxide. Depending on the application, a supplier’s datasheet might list any of these, which can make it a little tricky for buyers trying to cross-check regulatory databases or safety records. Most global regulatory lists recognize all these identifiers, but checking the full list of synonyms still matters for preventing mix-ups in technical documents or export paperwork.
Working with bronopol in the lab or on a factory floor, the health and safety team sets up rigorous procedures. Skin and eye irritation show up quickly after accidental splashes, and inhaling fine dust can bother the lungs. Chronic exposure, especially among workers in manufacturing plants without proper ventilation, has raised concerns about cumulative health risks, particularly as bronopol breaks down into trace bromide and nitrite compounds. On the consumer end, most products use bronopol below 0.1% concentration, and that’s largely considered safe for days or weeks of skin contact. Still, allergic reactions have popped up now and then—most linked to leave-on cosmetics—pushing many brands to switch to shorter-preserved products or at least flag bronopol on labels. Responsible manufacturing hinges on good airflow in bulk handling rooms, sealed containers during storage, and regular worker medical checks for dermal or respiratory sensitivity.
Bronopol first found its footing in the personal care sector, defending shampoos, creams, and lotions from bacteria in the shelf-life lottery, but engineers soon brought it to pulp and paper mills, where it kept cooling water and wet paper free of microbial slime. Oilfield operators and industrial water treatment plants now use bronopol as a biocide in injection water, tackling sulfate-reducing bacteria that cause souring and pipe corrosion. Hospital cleaning products, some over-the-counter disinfectants, and even select veterinary solutions still use bronopol when other preservatives either don’t work or risk disrupting the product’s feel and scent. Some regions have scaled back usage, especially in baby products or leave-on lotions, but few ingredients hit the same mix of antimicrobial power and easy formulation.
Academic groups and major chemical producers keep pressing for next-gen bronopol applications, especially for industrial water systems battered by growing resistance to basic biocides. Biologists study its breakdown profile in real-world settings, trying to find tweaks to slow the formation of nitrosamines, which cause regulatory headaches across much of Europe. Meanwhile, formulation chemists are experimenting with bronopol blends that use less overall preservative per product, layering multiple agents to gain similar protection with less risk of irritation or allergy. Trials in wound-care and surface sanitization are ongoing, especially where bacterial resistance or unconventional pathogens threaten to outpace classic control methods.
Toxicologists have kept their eyes on bronopol for decades, especially as traces show up in river runoff and wastewater plants. High doses show toxicity in lab animals, mostly tied to nitrite and bromide buildup, while skin patch tests in humans flag irritation at concentrations well above what commercial goods normally use. Of greater concern is the possibility for bronopol to form nitrosamines, a toxin linked to cancer in some studies. Regulatory authorities in the EU and US set strict limits on bronopol’s use in leave-on skin care and high-dose settings. Still, in properly formulated rinse-off products and industrial water, routine monitoring shows risk stays well under the bar, particularly with tight controls over pH and metal contamination during storage.
Bronopol’s spot in the world of antimicrobial chemicals stands in flux as companies weigh consumer safety trends, tightening environmental law, and the looming threat of superbugs. Some newer formulations keep the same bacteria-busting edge with lower use levels, mixing bronopol with milder acids or organic agents. Chemical firms pour research dollars into derivatives and blends that cut down formation of dangerous byproducts without losing reliable killing power. Market analysts predict that bronopol’s future could move toward specialized uses—like high-value medical devices or harsh industrial settings—where proven, potent preservatives still outshine most “natural” competitors. Scientists focusing on green chemistry keep up the pursuit for better breakdown pathways, searching for ways to break down both bronopol and its byproducts quickly at the end of their working lives. All signs point to a future where bronopol sticks around, but in tighter, more closely regulated niches with an eye on safety and sustainability.
Bronopol doesn’t turn many heads at the grocery store, but take a stroll through an industrial plant or visit a water treatment facility, and chances are someone’s working with this chemical. At its core, bronopol acts as a biocide—fighting off unwanted bacteria, yeast, and fungi that like to pop up anywhere water collects with organic material. In my time working with municipal water districts, the problem of microbial contamination showed up everywhere, from cooling towers to swimming pools. Let it slide, and the systems can turn into breeding grounds for everything from algae to dangerous bacteria. Bronopol helps cut down the risk.
People often overlook what it takes to keep things from going bad—literally. Bronopol plays a quiet role in extending the life of everyday products. In the cosmetics aisle, you’ll find it hiding inside makeup removers, shampoos, and skin creams. Bacteria love the damp, nutrient-rich environment these products offer, and no company wants a batch of face cream spoiling before it ever reaches a customer. A little bronopol can mean the difference between a lotion that glides on smooth and a jar that’s turned into a petri dish. My sister works in quality assurance for a big personal care brand, and I’ve heard her talk about the constant battle to keep formulas safe without sending users running for the doctor with an allergic reaction. This is a real balancing act.
Water treatment relies on bronopol, too. Municipal water utilities use it to control iron and sulfur bacteria that make water smell bad or cause corrosion in infrastructure. Oil and gas companies inject it into wells to keep pipelines clear—microbial growth builds up clogs and emits corrosive byproducts that eat away at metal pipes. Without something to stop that growth, companies end up with costly repairs and even emergency shutdowns. My neighbor once worked at a drilling site in Texas, and he told me stories about wellheads getting so gunked up with bacteria that entire systems had to be torn down and rebuilt. A preventative dose of bronopol can save money by sidestepping those headaches altogether.
With all its upsides, bronopol comes with baggage. Long exposure or high concentrations create risks for people handling the chemical—it can irritate skin, eyes, and breathing passages. Reports have found that when bronopol breaks down, it can release formaldehyde and nitrosamines—substances the scientific community links with health hazards. My own time on a safety review committee showed how quick people can be to overlook the dangers if they think the job looks routine. Direct handling should always call for gloves and goggles, and nobody should ignore ventilation.
Environmental persistence creates a second puzzle. Bronopol doesn’t hang around as long as some chemicals, but breakdown byproducts can still carry risks for local ecosystems. Countries like the European Union set strict rules about how much can end up in wastewater. Treatment plants have upgraded filtration and monitoring to catch any residues before they leave the facility. In industry, research teams work on alternatives that are safer and break down even faster in the environment, but for now, bronopol holds its ground in a lot of applications.
Companies and municipalities can train workers better, update safety gear, and keep up with the latest research. Cutting down on how much bronopol enters water systems—by using just enough, and switching to safer materials when possible—keeps workers and communities healthier. Biodegradable or plant-based preservatives are showing promise, but aren’t always tough enough for heavy-duty industrial jobs. With smart planning and honest assessment, industries can balance efficiency with safety, so this small molecule keeps doing the big jobs we rely on, without tipping the scales toward unnecessary risk.
Bronopol pops up in everything from household cleaners to cosmetics. Manufacturers like it for its ability to kill bacteria and fungi. Hospitals use it to keep medical equipment and environments clean. You can find it in shampoos, lotions, cooling fluids, even water treatment plants. The chemical smells slightly sweet, almost like medicine, so it’s familiar if you’ve opened a disinfectant or a topical skin ointment at home.
Bronopol got approval decades ago, long before people dug deep into the effects of small chemical exposures. The thing is, it works fast against bacteria. That’s helpful—few things spread germs as quickly as poorly cleaned surfaces or shared personal care products. So it makes sense that people saw Bronopol as a useful solution. It keeps mold away and helps creams or liquids last longer, which can help stop waste and extra expense for consumers. That reliability lowered infection risks in places like hospitals, factories and nail salons.
People ask about its safety for good reason. Scientific studies tell us Bronopol breaks down and produces formaldehyde under certain conditions. Formaldehyde causes skin irritation, allergies and even cancer after long-term exposure. Lab research connects repeated Bronopol contact with allergic reactions—itchiness, redness and rashes show up more often in folks with sensitive skin or eczema. One study highlights that Bronopol by itself rarely causes harm in short, occasional use, but products can move from “probably okay” to “riskier” if they combine Bronopol with other ingredients that also give off formaldehyde.
Poorly ventilated rooms or mixing multiple Bronopol products together makes things worse, especially for children and pets who spend longer closer to those surfaces. Bronopol also pollutes water supplies, and fish exposed to it struggle to survive. These aren’t small side effects; people juggling asthma, allergies or kids with sensitive skin have real reasons to check product labels.
It’s easy to trust what’s sitting on shelves, but real safety comes from informed choices and regulation. Some governments now place limits on Bronopol in cosmetics and personal care items—a strict maximum concentration, not a free-for-all. These limits change as scientists learn more about how the chemical breaks down in the body and the environment.
Switching to simpler products, buying from brands that don’t hide ingredient lists, reading packaging—you gain control over what comes into your home. Natural preservatives, careful labeling, and stronger rules for hazardous ingredients have all grown from concerns about products like Bronopol.
Very low doses found in consumer products don’t usually cause immediate problems for healthy adults. Danger grows with repeated use, mixing Bronopol products or leaving them on your skin for long stretches—think of lotions, makeup, baby wipes. That risk turns serious for workers who touch industrial forms of Bronopol every shift. Extra washing, gloves, and adequate ventilation cut down on trouble, but not everyone sticks to these precautions, especially at home.
The real takeaway is not panic, but awareness. Ask questions at your pharmacy, research ingredients before buying, support brands that skip Bronopol. Push for clearer rules, because everyone deserves honesty about what goes on their skin and into shared water. The science keeps growing, so safe habits and transparency should grow too.
Bronopol pops up in a range of personal care products, industrial water systems, and even some medicines as a preservative. Its antimicrobial punch keeps bacteria and fungi from growing in products like shampoos, lotions, and skin creams. In factories, it stifles bacterial slime in water systems. This chemical gets the job done, but stories from people who use these products and data from several health bodies point out that Bronopol is not always friendly to the skin or human health.
Folks with sensitive skin sometimes run into trouble with Bronopol. Redness, burning, or itching break out soon after a product containing the chemical goes on the skin. Over time, repeated exposure leads some people to deal with eczema or allergic contact dermatitis. In my pharmacy days, customers with persistent hand rashes often switched to Bronopol-free lotions and noticed relief within weeks. Testing backs this up: the American Contact Dermatitis Society put Bronopol on their “watch” list years ago, especially in folks with eczema or known fragrance allergies.
Most people think of skin reactions first, but inhaling Bronopol at work or at home carries risk too. Large industrial users, like those who maintain cooling towers, work in settings where vapors circulate. Studies done on rats show that breathing in vapors irritates the nose and lungs, bringing on symptoms like coughing or wheezing, especially with high doses or long-term exposure. Factory health surveys in Europe noted a link between Bronopol-containing mist and increased asthma rates among workers. Proper ventilation and masks cut down on complaints, but these protections sometimes get ignored until problems pile up.
Bronopol produces small amounts of nitrosamines as it breaks down. These byproducts raise red flags because many nitrosamines have shown cancer-causing potential in animal studies. Regulatory health agencies like the European Chemicals Agency warn that while these levels are low in personal care bottles, risk climbs in closed-cycle water systems and during heavy industrial use. Over the years, the European Union has lowered legal limits for Bronopol in cosmetics. America has not followed suit as aggressively, but watchdog groups push for change, calling for clearer labeling and safer alternatives.
For everyday users, checking ingredient lists helps. People with known allergies can pick up brands that skip Bronopol altogether. For industrial workers, workplace safety rules must become routine, not an afterthought. Wearing gloves, using proper fans, and monitoring air quality keep exposure in check and cut down on sick days.
Switching to less reactive preservatives in personal care products protects folks with sensitive skin. Natural options like potassium sorbate and sodium benzoate show fewer allergy complaints, though no preservative comes perfectly risk free. A patch test at a dermatologist’s office can pick up many preservative allergies before a rash flares up.
In the end, Bronopol does a specific job well, but not without baggage. Its side effects highlight the basic truth that no chemical safeguard works for everyone. Paying attention to skin, lungs, and new research lets both consumers and workers make safer choices where they can really count.
Bronopol turns up at workplaces that deal with water treatment, industrial fluids, and often in cosmetic or personal care labs as a preservative. People working with it know its bugs-control powers, but storing it without respect can put health, product quality, and even the environment at risk. Forgetting this step, or just getting sloppy, makes trouble more likely. Over the years, unsafe storage has caused headaches—from product recalls to workplace accidents.
Based on direct experience in quality control, humidity is Bronopol’s biggest enemy. Moisture kicks off breakdown, leading to dangerous byproducts such as formaldehyde. At my last plant job, one rainy week turned a carelessly sealed Bronopol drum into a sticky mess, triggering a scramble to fix contamination. Always keep it in an area with controlled temperature, away from heat sources. The best practice is a sealed, tightly closed container stored under 25°C, away from any direct sunlight, radiators, or poorly ventilated corners.
It’s easy for containers in a shared facility to get mixed up. One mislabeled drum can create confusion and real risks for anyone who grabs it next. Using tough, chemical-resistant containers with straightforward labels cuts out guessing. Experience shows that labels should not just feature the name, but include warnings, manufacturing date, expiry date, and hazard icons. It is never a good plan to transfer Bronopol into unmarked containers—this short-cut has landed companies in legal trouble and led to staff hospitalizations in the past.
Bronopol reacts badly with reducing agents and some organic materials. Mixing it accidentally with incompatible substances—even fumes nearby—jump-starts chemical reactions that can risk fires or release toxic gases. In a shared storage room, segregate Bronopol strictly from acids, alkalis, combustible organics, and strong reducing agents. Using designated shelves or locked cabinets helps cut the odds of cross-contamination.
Safe storage is not just about equipment—it’s a habit. New staff often overlook the basics, like checking that the lid is secured or recording temperature readings. Simple, routine training keeps everyone on the same page. At companies that treat storage like a team responsibility, leaks and accidents drop off fast. Scheduled inspections matter. Even experienced workers make mistakes if reminders aren’t built in. Regular checks catch small cracks or signs of moisture before they can start trouble.
Leftover Bronopol doesn’t belong down the drain or tossed in regular trash. Unsafe disposal creates bigger headaches, including environmental fines and long-term pollution. Facilities with clear disposal policies and easy-to-follow instructions have fewer accidents—and less stress for staff.
Why bother with all these steps? Everyone wants safe, reliable products and a workplace that sends people home healthy. By making Bronopol storage a priority, quality stays high, accidents fall, and regulatory headaches stay rare. Safe storage shows respect—not only for the material but for the people handling it and for the wider community.
Bronopol gets plenty of attention in the world of preservatives and biocides. You’ll spot it in everything from cosmetics to industrial water systems, even though most people using these products don’t realize it’s there. The main job for Bronopol is fighting bacterial growth. Its chemical formula means it can disrupt a range of microbes—Staphylococcus, Pseudomonas, and even some strains that resist other treatments—so you get longer shelf life and less risk of spoilage.
Most supermarket shampoos or lotions need to stay fresh for a long time, riding out warm storerooms and humid bathrooms. In my own years working with raw ingredient suppliers, nothing threatened a batch faster than surprise contamination. We’d run challenge tests with Bronopol, watching how it broke down cell walls and stopped bacterial colonies from spreading across the agar plates. Clear spots—no bacteria—meant the stuff worked, every time. Yet labs and real life aren’t always the same. Bacterial loads in the lab rarely match what you find in a leaky shipping crate or dirty water tank.
Many regulations now limit Bronopol concentrations, especially in personal care. More brands worry about byproducts like formaldehyde, which can form when Bronopol breaks down under certain conditions. Customers expect clean labels and harsh preservatives aren’t welcome. The truth is Bronopol does a number on Gram-negative bacteria and even holds off spores from Gram-positive strains, but even a proven biocide stops short against every threat.
Plenty of people talk about Bronopol’s strength against bacteria. The fungal story feels different. Molds and yeasts, common troublemakers in damp household products, laugh at some traditional preservatives. Bronopol slows their growth, but nowhere near as effective as with bacteria. My first antifungal test with Bronopol showed some reduction, but colonies still crept across the dish unless we mixed in extra support like parabens or isothiazolinones. Fungal cell membranes and enzymes demand more specialized intervention.
Industries using Bronopol learn quickly: don’t rely on one ingredient to handle every challenge. The smartest companies layer protection—using Bronopol mainly for bacteria then pairing it with antifungal chemicals to guard against black mold, yeast, and other durable fungi. Some companies source recipes that combine acids, alcohols, and even silver-based preservatives to hit every possible angle. From personal use, I know nothing’s worse than opening a favorite cream, only to catch that musty scent that means fungus won.
Greater consumer transparency and tougher regulations push innovators to explore new molecules and gentle blends. Kathon, phenoxyethanol, and sorbic acid all compete for shelf space once reserved for Bronopol. Some new solutions rely on plant extracts or fermented compounds, which show promise for handling both bacteria and fungi without the harsh side effects. Still, switching isn’t quick. Every swap-out means full testing—stability checks, patch tests, long-term shelf trials. Factories require retraining; labeling and distribution systems need updates. These changes take time, money, and engineering know-how.
Bronopol sticks around in many formulations because it delivers results, particularly on the bacterial side. Companies and consumers aware of health concerns make educated choices—reading ingredient lists, asking questions, pushing for greener options. For anyone in charge of production safety, the key is respect for these risks and honest communication about strengths and limitations. The world won’t toss Bronopol aside tomorrow, but new doors keep opening for smarter, less aggressive ways to keep products safe.
| Names | |
| Preferred IUPAC name | 2-bromo-2-nitropropane-1,3-diol |
| Other names |
2-Bromo-2-nitropropane-1,3-diol BNPD Bronosol Bronocot Bronon Myacide Aseptin Onyxide 222 Cereform Dix Asept |
| Pronunciation | /ˈbroʊ.nəˌpɒl/ |
| Identifiers | |
| CAS Number | 52-51-7 |
| Beilstein Reference | 3599282 |
| ChEBI | CHEBI:73004 |
| ChEMBL | CHEMBL1565 |
| ChemSpider | 5756 |
| DrugBank | DB00852 |
| ECHA InfoCard | 03e1d8e9-d67e-4331-a587-6bf1f5915760 |
| EC Number | 200-143-0 |
| Gmelin Reference | 69312 |
| KEGG | C10468 |
| MeSH | D001976 |
| PubChem CID | 2459 |
| RTECS number | DJ6125000 |
| UNII | WB0N3F5F94 |
| UN number | UN3241 |
| Properties | |
| Chemical formula | C3H6BrNO4 |
| Molar mass | 199.991 g/mol |
| Appearance | white crystalline powder |
| Odor | Odorless |
| Density | 1.31 g/cm³ |
| Solubility in water | 0.25 g/mL (20 °C) |
| log P | 0.18 |
| Vapor pressure | 2.48E-3 Pa (25 °C) |
| Acidity (pKa) | 11.57 |
| Basicity (pKb) | 7.96 |
| Magnetic susceptibility (χ) | -51.0e-6 cm³/mol |
| Refractive index (nD) | 1.617 |
| Dipole moment | 2.71 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 170.5 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | -216.0 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | -2481 kJ/mol |
| Pharmacology | |
| ATC code | D08AJ06 |
| Hazards | |
| Main hazards | Harmful if swallowed, causes skin irritation, causes serious eye irritation, may cause an allergic skin reaction, very toxic to aquatic life. |
| GHS labelling | GHS07; GHS05; Warning; H315, H319, H335, H302 |
| Pictograms | GHS05,GHS07 |
| Signal word | Warning |
| Hazard statements | H302, H318, H400 |
| Precautionary statements | P273, P280, P305+P351+P338, P337+P313, P501 |
| NFPA 704 (fire diamond) | 2-0-0-☣ |
| Flash point | > 138°C |
| Autoignition temperature | > 250 °C |
| Lethal dose or concentration | LD50 (oral, rat): 305 mg/kg |
| LD50 (median dose) | LD50 (median dose) of Bronopol: "180 mg/kg (oral, rat) |
| NIOSH | ZE4200000 |
| PEL (Permissible) | PEL (Permissible Exposure Limit) for Bronopol: "Not established |
| REL (Recommended) | 0.1 |
| IDLH (Immediate danger) | Unknown |
| Related compounds | |
| Related compounds |
Bromochlorohydroxypropane Chlorhexidine Bromodichlorohydrindene 2-Bromo-2-nitropropane-1,3-diol derivatives |
