Dipotassium hydrogen phosphate, or K₂HPO₄, carries a track record rooted in both the growth of chemical manufacturing and the expansion of agricultural science. Early chemical innovators in the 19th century recognized potassium salts as valuable plant nutrients, and soon phosphates made their way from curiosity to commodity. My own exposure began in university labs, though farmers and scientists in the 1800s were already turning to potassium phosphates to shore up depleted soils. Early preparation techniques involved processing animal bones for phosphorus and running simple double decomposition reactions. Over time, more efficient routes came online, scaling up production for fertilizer and industrial uses. Advances in purity and process automation boosted its adoption, setting the stage for today’s flexible product formats and applications.
K₂HPO₄ shows up in labs and industry as a granular or crystalline powder, white in color, without odor. Away from the sample kits and into the warehouse, you’ll find large sacks and drums stamped with batch codes and compliance numbers. Companies use several names for it, including potassium phosphate dibasic, dipotassium phosphate, and secondary potassium phosphate, reflecting slight shifts in chemistry or application. Each label points back to this reliable, quick-dissolving salt. It’s recognized for its clean taste profile and stable behavior in processing environments, which matters when you use it for food additives, buffer solutions, or crop nutrition.
Looking at the white powder on a lab bench, the basic numbers matter: K₂HPO₄ melts at around 340°C, dissolves smoothly in water, and doesn’t catch fire. It offers a pH range just below neutral when dissolved, keeping solutions steady under a range of temperatures and conditions. Its density rests at roughly 2.44 g/cm³, with high solubility making it easy to use wherever consistent ions are needed. The compound crystallizes in a monoclinic lattice, a detail that might sound academic until you’re trying to separate it from similar salts.
You won’t get far with bulk chemical supply chains without meeting standards. Producers offer technical and food grades, with potassium content and phosphate purity spelled out on every certificate of analysis. Good labeling steps keep operators safe and quality lines clear—look for hazard statements, recommended storage temperatures, and instructions for spill management. My time helping in a chemical warehouse showed me that lots of missteps start with sloppy packaging or faded labels. Every genuine shipment lays out batch history and composition, plus notes on moisture content, so users match product to process without costly guesswork.
On the production side, manufacturers often create K₂HPO₄ by reacting phosphoric acid with potassium carbonate or potassium hydroxide. I’ve watched operators charge reactors with careful portions and monitor exotherms that tell them the reaction’s heading in the right direction. Neutralization needs close control of pH, with product crystallizing as water evaporates off. After filtration, drying, and milling, the finished powder heads through testing before release. Alternative routes will use different grades of starting materials, but every approach balances purity, efficiency, and downstream safety.
In lab work, you see K₂HPO₄ go into buffer solutions, stabilizing pH in biochemical reactions. That’s just the start—mix it with monopotassium phosphate (KH₂PO₄) to tailor phosphate levels in solution, or react it under heat to slide towards tripotassium phosphate. These transformations pop up all over water treatment, food chemistry, and battery development. I’ve spent long hours tweaking buffer concentrations to get enzymes humming along, proof that small changes in phosphate balance can make or break experiments.
Industry documents and academic articles throw several names at K₂HPO₄, making quick research a trickier job than expected. Besides potassium phosphate dibasic and dipotassium phosphate, you’ll see references to potassium hydrogen orthophosphate or secondary potassium orthophosphate. Brand names cycle through as suppliers merge or rebrand, yet global standards rely on the IUPAC naming system for clarity. In practice, you bump into code numbers for food additives—E340(ii) in Europe—pinning down its identity in global commerce.
Workplaces handle K₂HPO₄ with routine but solid caution. It’s not explosive or especially toxic, but dust can irritate skin, eyes, and lungs, so gloves and goggles remain non-negotiable. Material safety data sheets spell out best practices: store bags in cool, dry places, keep containers sealed, and deal with spills using simple containment and disposal steps. Accidents tend to come from inattention rather than surprises in chemistry. I’ve seen near-misses cleaned up quickly thanks to good training and clear safety culture, which keeps regulatory agencies mostly content.
K₂HPO₄ works overtime across industries. In agriculture, growers add it to fertilizers, taking advantage of both potassium and phosphorus nutrients, boosting root growth and yields. Food manufacturers use it for buffering dairy products, stabilizing whipped cream, or balancing pH in processed meats. Pharmaceuticals lean on its buffering action to make injectable medicines safer and more compatible with the human body. Water treatment engineers choose it to sequester hardness ions and prevent scale buildup. I’ve seen it in everything from yeast nutrient mixes for brewing to electrolytes for modern battery research. Research labs run through kilos keeping their cell cultures steady and experiments reproducible.
Lab teams continue to search for new uses and blend modifications. Recent years bring new energy storage devices requiring high-purity phosphate salts. Agriculture scientists look to use dipotassium hydrogen phosphate in precision nutrient blends, dialed in for specific crops and soil types. Environmental researchers want more data on phosphate leaching and its role in water eutrophication; they push for controlled-release formulations or biodegradable alternatives. Food technologists eye lower-sodium versions to meet updated dietary goals. On a personal note, I’ve found that every time a new application crops up, supply chains and makers draw up tighter specs—all part of a race to offer more effective and sustainable phosphate materials.
Research into toxicity underscores the relative safety of K₂HPO₄ at recommended levels. Large doses can upset body electrolyte balance, a real concern in poorly formulated food products or industrial accidents. Animal studies and regulatory reviews mark it as a low-to-moderate hazard, mainly through the risk of irritation or, in rare cases, effects on kidney function with chronic overexposure. Environmental persistence of phosphates calls attention from scientists worried about harmful algal blooms and aquatic ecosystem shifts. Ongoing studies continue to map out metabolic pathways and investigate longer-term impacts, prompting guidelines for further limits and monitoring in agriculture and food use.
Industry watchers expect more demand for dipotassium hydrogen phosphate as world agriculture strives for higher yields and new food-processing trends lean into phosphate-based solutions. Shifts in battery manufacturing add unexpected requirements for high-purity salts, moving market priorities. Environmental guidelines shape how and where these chemicals get used. The push for sustainable farming, stricter water-quality standards, and safer food packaging drives chemistry labs to invent greener, less persistent alternatives. My own experience suggests the next decade will see much more focus on circular processes, energy-efficient synthesis, and better monitoring for runoff or contamination. Regulatory pressure plus market need puts innovation front and center as the next chapter for this historic, adaptable compound unfolds.
You probably don’t spot “dipotassium hydrogen phosphate” on your grocery list, but it shows up in plenty of places outside your chemistry textbook. In agriculture, K2HPO4 helps crops grow by putting both potassium and phosphorus into the soil. That’s a big deal, especially on farms trying to squeeze maximum yield from every acre. Potassium makes plants sturdier, helps them fend off drought, and lets roots bring up water. Phosphorus gives seeds the start they need for strong roots and blooms. When farmers put K2HPO4 on their fields, they’re setting up their plants for a stronger harvest—something that matters a lot with unpredictable weather and ever-rising food demand.
Inside food factories, K2HPO4 does a quieter but important job. It keeps powdered drinks, dairy products, and even some veggie meats tasting right and keeping their texture. Too many phosphates can mess with health, but add the right amount and you get cheese that melts, pudding that stays creamy, and instant drinks that mix smoothly. These food jobs shape what we see on our plates and influence how healthy it is to eat “processed” food. Ingredients like K2HPO4 remind us to care about what’s in our meals, not just what’s on the front of the box.
In the lab and hospital, K2HPO4 looks less like a farm tool and more like an essential helper. Doctors rely on phosphate solutions when they need to balance electrolytes for people hooked up to IVs. Blood pH can wobble dangerously when patients are sick. K2HPO4 steps in, helping to keep that balance right. In my days working around hospital labs, I saw how vital these simple salts could be. The difference between a patient bouncing back or running into trouble sometimes hung on those invisible chemical numbers on a blood test.
It’s not just inside people. Lab researchers use K2HPO4 as a buffer that keeps experiments steady. Enzyme tests or DNA work go off the rails if acidity swings. So anyone serious about making discoveries in biology and medicine counts on salts like this to keep things predictable, repeatable, and in the right chemical range. It’s a behind-the-scenes player, but without it, the flashy moments in medical science wouldn’t happen.
The story doesn’t end with just “it works.” K2HPO4 can’t fix every problem. Farms can wind up with phosphorus runoff, polluting rivers and pushing algae blooms that choke fish. In food, some doctors warn us about eating too many phosphates, especially if your kidneys don’t filter well. And in health care, IV salts only help if used carefully—a dose too high or too low can trigger its own set of problems.
We can do better. Smarter farm practices, like testing soil before using fertilizers, help keep nutrients in the right place. Tighter food regulations and honest ingredient labels let shoppers make safer choices and nudge companies to use only what’s needed. In hospitals, regular staff training and better monitoring keep patients safer. All these steps build a stronger system that doesn’t just rely on old shortcuts.
K2HPO4 won’t ever headline the news, but its effects show up in full grocery aisles, safer hospitals, and cleaner rivers. That’s more than just chemistry—it’s a choice about how we live and how much we pay attention to the ingredients behind the scenes.
K2HPO4 stands for dipotassium hydrogen phosphate. It’s a chemical compound that carries two potassium atoms, one hydrogen, one phosphorus, and four oxygens. Most people never hear its name outside a chemistry lab, but you’ll find it listed on ingredient labels of food products, nutritional supplements, and even some pharmaceuticals.
Read the back of a processed food package and K2HPO4 might pop up in the fine print. The food industry uses it to regulate acidity and to prevent certain foods from caking or clumping. Cheese spreads, powdered creamers, sports drinks, and jelly beans have all relied on it at some point. As a food additive, the FDA groups K2HPO4 with those counted as “generally recognized as safe.” That’s a seal of approval, but reading between the lines is essential here.
Our bodies depend on potassium and phosphate. Bananas and potatoes add potassium to our diets, while dairy and meats cover the phosphorus side. Both minerals handle important work: they help muscles contract, keep bones strong, and balance fluids. K2HPO4’s claim to fame is that it delivers a double dose of both, and this is why food manufacturers like having it around.
Trouble enters when intake goes through the roof. The body expects a certain range. If you’re healthy, an extra pinch from a packet of processed food won’t matter. But if kidneys aren’t working properly, phosphate and potassium can start building up in the blood. That’s when real health risks make an appearance, mostly for people with chronic kidney disease, heart problems, or those who follow special diets for medical reasons.
Scientists have studied the effects of consuming phosphate additives. Average people eating a regular diet don’t usually experience harm from the small amounts found in food. Some sources point to possible side effects, like digestive upset or a rare risk of electrolyte imbalance, but usually only if someone is chugging down supplements or treatments in high doses, not eating regular food. All food additives get evaluated and reviewed, but the system relies on the assumption that people follow normal eating habits and that no health conditions skew the results.
If your health is steady and you’re not eating processed foods all day, the amount of K2HPO4 in your food probably won’t cause a problem. The trouble comes with overconsumption and from relying too much on foods with added phosphates. People with kidney, heart, or certain hormonal issues, or anyone on a restricted diet, should keep an eye out for ingredients like K2HPO4 and talk it over with their doctor or dietitian. High phosphate levels can lead to weak bones, itchy skin, and complications you don’t want to tangle with.
Living in a world packed with chemicals, additives, and long ingredient lists doesn’t mean giving up food you love. Cooking at home more often cuts down on how many additives sneak onto your plate. Focusing on foods in their simplest forms gives your body less to process. Checking labels helps too, especially for people who manage a health condition where minerals need extra attention. Health comes from habits built day by day, not any one ingredient or meal. Open conversation with a doctor or nutritionist always beats guessing.
Most folks working in labs or with fertilizers will recognize K2HPO4 as dipotassium hydrogen phosphate. It’s a solid, white powder that does a ton of heavy lifting in chemistry, food science, and farming. Trouble comes not from its usefulness, but from people getting sloppy with storage or handling. I’ve seen it go south plenty of times, often because of small mistakes. You get a leaky bag or humidity seeps in, and suddenly you’ve got a clumpy mess that no one wants to use. Moisture is the biggest enemy here; this stuff loves to grab water out of the air and turn into a sticky nuisance.
From what I’ve seen, storing K2HPO4 well starts with two simple things: keep it dry, and avoid letting the temperature swing too much. Leave the fancy explanations to others. In the real world, this means airtight containers, strong shelving off the floor, and a place that doesn’t get blasted by sunlight. If you leave this powder sitting open, pretty soon you end up with hard chunks or a sludge that ruins the batch.
Let’s say your chemical closet feels muggy—a cheap fix is buying some silica gel packs or using a dehumidifier. It doesn’t have to be complicated. In busy labs I’ve worked in, people write reminders on the lids. “Keep closed—will clump!” A little bit of paranoia keeps the material usable.
There’s a lot of talk about safety data sheets, and those are helpful. Still, it helps to remember why some rules exist. K2HPO4 won’t catch fire easily, isn’t explosive, and doesn’t smell like trouble at first glance. But if you breathe in the dust or spill it on your skin for too long, it irritates. I’ve known technicians who thought gloves and goggles were overkill—right up until they left a powder trail across the workbench and felt it itch. You won’t see dramatic reactions, but over time, careless habits add up.
Eyes need protection. Don’t eat near it, wash your hands well, and skip the open sandals. At the very least, keep a small first aid kit nearby. Spills are simple: sweep it up, don’t splash with water, and avoid using a vacuum cleaner that could shoot dust back into the air.
In agriculture, waste bites into your wallet. Letting K2HPO4 soak up moisture or get contaminated cuts its performance as a plant nutrient. It’s the same in the food industry—losing a batch over careless handling means more than wasted powder, it means wasted money and lost time. I’ve worked with warehouse teams who quickly learned to double-check drum seals and rotate stock. Clear labeling kills confusion.
Don’t leave it to guesswork. If a container shows any sign of trouble—wetness, caked powder, odd discoloration—move it for safe disposal. Mixing in a spoiled batch with a fresh one spells disaster for product quality. Managers who encourage regular inspections see fewer headaches, and production runs more smoothly.
It pays to train staff well on how to handle K2HPO4, no matter if the work is in a high school science room or a commercial plant. I’ve watched smart teams make simple changes—like setting up easy-to-read checklists for storage areas—and the headaches drop overnight. Routine reminders keep the basics fresh in everyone’s mind. Look after your chemicals, and they’ll do the work you paid for—no mess, no fuss.
Dipotassium Hydrogen Phosphate sounds like a mouthful, but it’s one of those reliable chemicals you’ll bump into in school labs, agriculture, and even some food products. Its chemical formula is K2HPO4. That shorthand packs in two potassium atoms, a hydrogen atom, a phosphorus atom, and four oxygens. Simple enough, but tucked inside are rows of interesting uses and a surprising reach into daily life.
This formula tells a pretty clear story. Potassium leans in with a +1 charge, while the hydrogen phosphate bit pulls a -2. Team them up and balance out the charges—you’ve got yourself a salt that’s soluble, useful, and affordable. Walk through most fertilizer mixtures and you’ll bump into compounds like this. They help plants get the right mix of phosphorus and potassium.
Now to the numbers. Add up the atomic weights: potassium (roughly 39.10 g/mol) comes in twice, hydrogen (1.01 g/mol), phosphorus (30.97 g/mol), and oxygen (16.00 g/mol) times four. Get your calculator:
Total that up and you’re looking at 174.18 g/mol for the molecular weight. More than trivia, this figure means something in practice. Recipes for lab buffers or food additives rely on hitting this weight right, so you don’t overshoot and throw off a reaction or mix.
I remember my first real job in a greenhouse, long before chemistry classes made me memorize anything. Mixing up water-soluble fertilizers, I was told to double-check every label and measure. Getting it wrong didn’t just waste money; plants sometimes stalled or burned up. Dipotassium hydrogen phosphate delivers phosphorus that feeds root systems, especially in tired soils where other nutrients can’t do the trick alone.
On the industrial side, blending precise amounts keeps things steady, and that molecular weight saves headaches. Engineers and food scientists turn to this compound for its straightforward handling—fewer surprises during mixing or storage. Pure salts like this, when kept dry, store safely for months or even years and don’t gum up equipment.
Problems start if people toss it around without paying attention. Too much phosphorus runoff—whether from fertilizer overuse or sewage—has choked rivers and led to dead zones where fish stop biting and algae take over. We need phosphorus for food security, but careless use pushes up costs downstream, with taxpayers footing the bill for water cleanup.
Farms and manufacturers look for ways to recycle phosphorus or slow its loss. Some trial closed-loop systems or switch to smarter spreading methods. Labs experiment with using sensors that read soil nutrient levels before ordering up a batch of dipotassium hydrogen phosphate. These ideas cut costs and keep streams clearer, showing that knowing your molecular weights can end up mattering a lot outside the classroom.
Anyone who has ever mixed a buffer, fed houseplants, or checked out food ingredient lists has brushed up against K2HPO4. Its straightforward formula and predictable weight make it popular—but its full story comes out when folks start thinking about what happens after the mixing, not just before it.
K2HPO4, or dipotassium hydrogen phosphate, crops up a lot more than folks might guess. Some see it on fertilizer bags, some in food ingredient lists. The real question: What happens if you pour it into water? Will it dissolve, or just clump at the bottom?
In my years of fiddling with lab solutions and backyard gardening, I’ve dumped my fair share of salts into water, hoping for something clear. K2HPO4 always acts like the show-off in the group—hits the water, stirs around, disappears without a fuss. That’s no accident; nature built plenty of potassium and phosphate salts to dissolve easily, and this one follows the script. Many people learning chemistry worry about solubility rules, but all the experience, the reports, the manuals back it up: K2HPO4 dissolves, and fast.
You find this salt in more spots than a simple lab. Take fertilizer mixing, for example. If you have a hydroponics setup, or if you’re a farmer prepping a spray tank, you need those nutrients to dissolve so plants get their dose. Dumping something like K2HPO4 into water means you don’t have to worry about rocks at the bottom of the tank — nutrients reach the roots straight away. Fewer clogged hoses, no angry customer calls about uneven patches in the field.
Food processing has its share of uses for dipotassium hydrogen phosphate too, especially as a buffer or mineral source. In my time working with commercial kitchens and food scientists, trouble pops up when a salt leaves behind stubborn grains. Nobody wants gritty cheese sauce or chalky beverages, so solubility scores big points here. Clear liquids, smooth textures, reliable recipes: all possible because somebody in the process knows K2HPO4 will dissolve.
A lesson learned doing late-night lab prep: some salts cling together and fight the water, others give in and break up instantly. K2HPO4 sits with the easy crowd. Its ions—the potassium and the hydrogen phosphate—feel perfectly at home in water, like old friends mixing into the party. That’s because water does a great job prying these ions apart, letting them float freely. There’s a reason why university classes keep coming back to this one during demonstrations.
Picture a world where K2HPO4 refused to go clear. Fertilizer systems would jam, nutrient uptake would drop, and folks in commercial kitchens would scramble for alternatives. Even small operations would face new costs as they hunt down soluble blends. I’ve talked to folks who tried cheaper substitutes, only to wind up fighting blockages and uneven mixing. It’s clear: the world runs smoother with salts that dissolve where they’re told.
If ever supply chain hiccups or regulatory changes threaten access to reliable K2HPO4, keeping tabs on solubility of replacements becomes priority one for buyers and operators. Testing in-house, leaning on honest lab results, and swapping stories with other users keeps frustration low and production high. It pays to lean on experience and not just believe the label. In the end, real performance comes down to what you see in the tank, in the glass, or in the food — clear, fast, and without a catch.
| Names | |
| Preferred IUPAC name | potassium hydrogen phosphate |
| Other names |
Dipotassium phosphate Potassium phosphate dibasic Dibasic potassium phosphate Phosphoric acid, dipotassium salt Potassium hydrogen phosphate |
| Pronunciation | /daɪ.poʊˈtæs.i.əm haɪˈdrɒ.dʒən fəˈsfeɪt/ |
| Identifiers | |
| CAS Number | 7758-11-4 |
| Beilstein Reference | 3587154 |
| ChEBI | CHEBI:13008 |
| ChEMBL | CHEMBL1201734 |
| ChemSpider | 61110 |
| DrugBank | DB09449 |
| ECHA InfoCard | ECHA InfoCard: 157835 |
| EC Number | 231-834-5 |
| Gmelin Reference | 78444 |
| KEGG | C14537 |
| MeSH | Dipotassium Phosphate |
| PubChem CID | 24450 |
| RTECS number | TC6615500 |
| UNII | VZ8Z5M419C |
| UN number | UN9149 |
| Properties | |
| Chemical formula | K2HPO4 |
| Molar mass | 174.18 g/mol |
| Appearance | White crystalline powder |
| Odor | Odorless |
| Density | 2.44 g/cm³ |
| Solubility in water | 167 g/100 mL (20 °C) |
| log P | -4.1 |
| Vapor pressure | Negligible |
| Acidity (pKa) | 7.2 |
| Basicity (pKb) | 12.4 |
| Magnetic susceptibility (χ) | -57.0·10⁻⁶ cm³/mol |
| Refractive index (nD) | 1.332 (20 °C) |
| Dipole moment | 3.2 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 157.5 J·K⁻¹·mol⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | -2041.1 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | –2877 kJ/mol |
| Pharmacology | |
| ATC code | B05XA03 |
| Hazards | |
| Main hazards | May cause irritation to eyes, skin, and respiratory tract. |
| GHS labelling | GHS07, Warning, H319, P264, P280, P305+P351+P338, P337+P313 |
| Pictograms | GHS07, GHS09 |
| Signal word | Warning |
| Hazard statements | Hazard statements: Not a hazardous substance or mixture according to Regulation (EC) No. 1272/2008. |
| Precautionary statements | P264, P270, P305+P351+P338, P337+P313 |
| NFPA 704 (fire diamond) | 0-0-0 |
| Explosive limits | Explosive limits: Non-explosive |
| Lethal dose or concentration | LD50 (oral, rat): 4480 mg/kg |
| LD50 (median dose) | LD50 (median dose): Oral, rat: 17000 mg/kg |
| NIOSH | TC3875000 |
| PEL (Permissible) | PEL (Permissible Exposure Limit) for Dipotassium Hydrogen Phosphate K2HPO4: Not established |
| REL (Recommended) | 0.5 mg/m³ |
| IDLH (Immediate danger) | Not listed. |
| Related compounds | |
| Related compounds |
Potassium dihydrogen phosphate (KH2PO4) Monopotassium phosphate (KH2PO4) Tripotassium phosphate (K3PO4) Disodium hydrogen phosphate (Na2HPO4) Diphosphates Phosphoric acid (H3PO4) |
