Trisodium citrate anhydrous stepped onto the chemical stage through curiosity about how acids and bases interact. Scientists in the early nineteenth century took note of the tartness in fruits like lemons and limes, sparking interest in citric acid’s sodium salt. As industry and food preservation grew, experts recognized the value of sodium citrate for buffering and stabilizing food products. By the mid-twentieth century, researchers refined the production methods, shifting away from extraction from citrus juice to synthetic routes using fermentation followed by neutralization. These shifts traced the broader arc of industrial chemistry, where agricultural waste, fermentation science, and industrial hygiene progress all converged.
Trisodium citrate anhydrous appears as a white, crystalline powder, notable for being free-flowing and easily soluble in water. In practice, it turns up in many foods, pharmaceuticals, and even industrial formulations. In the kitchen or laboratory, it tastes mild and salty, less sharp than citric acid but certainly not flavorless. Beyond food, hospitals rely on trisodium citrate anhydrous to prevent blood from clotting in test tubes, and manufacturers use it to adjust pH or act as a cleaning agent. This versatility anchors trisodium citrate in a host of products that people encounter from breakfast tables to dialysis wards.
Chemically, trisodium citrate anhydrous carries the formula Na3C6H5O7. The molecular weight sits at 258.07 g/mol. The powder dissolves readily in water, generating a slightly alkaline solution with a pH in the range of 7.5 to 9.0 at reasonable concentrations. It will not dissolve in ethanol. The melting point, usually above 300°C, reveals its thermal stability, making it practical for a wide range of heating applications. As for storage, the anhydrous form keeps well in airtight packaging, resisting caking and maintaining its flow. These properties, taken together, keep manufacturers coming back to trisodium citrate when reliability matters.
Industry organizations set specifications for trisodium citrate anhydrous to guide purity, moisture content, heavy metal limits, and microbial safety. Quality standards such as those from the Food Chemicals Codex and the United States Pharmacopeia call for content of at least 99.0% and water content below 1%. They also cap arsenic, lead, and other contaminants at trace levels. Labels must include grade (food, pharmaceutical, or industrial), batch numbers, manufacturing date, shelf life, and storage advice. Many regions also require allergen status and, in the case of the European Union, labeling for genetically modified organism (GMO) status if fermentation feedstock was not non-GMO. These rules serve both consumers and handlers by reducing confusion and enhancing traceability.
The process usually starts with fermentation of glucose using Aspergillus niger or a similar mold to produce citric acid. Neutralization by sodium carbonate or sodium hydroxide follows, yielding a solution of trisodium citrate. The solution undergoes purification via filtration and sometimes ion exchange resin treatment. Subsequent steps involve evaporation under vacuum to drive off water and encourage crystallization. The crystals are separated and thoroughly dried to produce the anhydrous version. Operators monitor the process vigilantly at every stage to spot contamination, check sodium ratios, and keep costs in line. This reflects both the critical nature of quality assurance and industry competition for efficiency.
Trisodium citrate anhydrous takes part in straightforward acid-base reactions, neutralizing acids while yielding weakly basic solutions. In water treatment, it forms soluble complexes with metal ions, easing scale removal or adjusting the chemistry of treated water. Mixed with calcium chloride, trisodium citrate forms calcium citrate, which precipitates out—an essential trick in some cheese-making recipes. Chemists have tinkered with varied derivatives, such as substituting different alkali metals for sodium or using mixed sodium-potassium salts for specific medical or food needs. Such modifications reflect attempts to optimize performance, manage sodium intake in diets, or meet the evolving safety preferences of consumers and regulators.
Trisodium citrate goes by several other names, depending on context and market. Common synonyms include sodium citrate, citrate, Citrosodine, and E331 (under European food additive regulations). Some suppliers group it under simply “citrate buffer,” particularly where its role is pH control. Packers and exporters often use local-language translations, which can sow confusion across borders. Awareness of these synonyms and model names benefits sourcing teams and R&D departments alike, preventing mix-ups that might disrupt production or violate labeling laws.
Most authorities regard trisodium citrate as safe when used at approved levels in food and medicine. The U.S. Food and Drug Administration places it on its GRAS (Generally Recognized as Safe) list. Occupational standards tell workers to use gloves and goggles during bulk handling to avoid temporary eye and skin irritation. Accidental ingestion of concentrated dry powder causes stomach discomfort or, in extreme cases, vomiting or diarrhea. Emergency protocols call for flushing eyes or skin, and keeping the material off wounds. Companies store it in cool, dry places in tightly sealed containers, away from acids or strong oxidizers. Staff training around spills, labeling, and safe dilution practices brings assurance that safety keeps pace with supply chain demands.
In daily life, trisodium citrate anhydrous plays support roles in many industries. As a food additive, it prevents crystallization in ice cream and dairy products, supports even melting in processed cheese, and acts as a pH buffer in soda and energy drinks. Hospitals and clinics use it to preserve blood, anticoagulate plasma for lab testing, and control acidosis in certain patient populations. Cleaning product formulators use its buffering and chelating abilities in detergents and household cleaners. Laboratories worldwide depend on its stability and buffering value to run reliable chemical tests. Every box or bag of trisodium citrate represents a web of industry, science, and daily reliance stretching from food safety to medical therapy.
Research around trisodium citrate focuses both on process improvements and fresh application areas. Chemists work on cleaner fermentative routes, using non-food crops or industrial byproducts to lower environmental impact and stabilize prices. Pharmaceutical scientists test new formulations of citrate-based anticoagulants that target safer, more predictable patient outcomes. In consumer products, food science teams adjust citrate levels to boost shelf life and reduce sodium without compromising taste. Some environmental groups seek to expand trisodium citrate’s role in treating metal-contaminated wastewater or replace harsher chemicals in specialty cleaners. As the chemical and food industries evolve, the R&D push reflects both innovation demands and tighter regulatory scrutiny.
Years of toxicology tests generally show trisodium citrate as low-risk at usual dietary or pharmaceutical concentrations. Studies track everything from acute oral exposure in rodents to long-term dietary addition, with regulatory agencies reviewing the results for signs of carcinogenicity, reproductive hazards, or other chronic outcomes. Human trials looking at kidney function, sodium levels, and acid-base balance help refine safe dosage guidelines for patients needing citrate therapy. One area still drawing attention involves special populations—especially those with compromised kidney function—where careful adjustments help guard against hypernatremia or other imbalances. Science keeps pressing for more data, better understanding, and communication of safe handling and dietary limits to close any gaps for workers, patients, and consumers.
Trisodium citrate anhydrous stands poised for a bigger role in future food, pharmacy, and industrial landscapes. Plant-based foods, non-dairy cheeses, electrolyte beverages, and medical infusions all drive demand for reliable acid-base control and mineral balancing. Sustainability targets push chemists to discover greener production pathways and packaging that cuts waste. Regulators, eager for safer, transparent, and traceable additives, look to digital monitoring and data-rich labeling. Researchers continue to explore new uses in green chemistry, water treatment, and personalized nutrition. Trisodium citrate’s versatility owes much to its long, practical track record, while its next chapter could see even wider adoption driven by technology, changing diets, and the ongoing search for safer, affordable ingredient choices.
Open the kitchen pantry and you probably spot it in your favorite powdered drink, or maybe it’s lurking behind the scenes in that slice of sharp cheddar on your sandwich. Trisodium citrate anhydrous doesn’t sit on most grocery lists, but it pulls a lot more weight in food processing than folks often realize. It acts as a buffering agent, which helps foods and drinks keep a stable pH. Think soft drinks—too acidic, and the can could corrode; too bland, and nobody wants a second sip. Trisodium citrate lends a hand, balancing tang with drinkability, giving products like lemonade powders or flavored waters a crisp, refreshing consistency without leaving your tongue feeling raw.
Melted cheese dishes owe their creamy stretch to more than just dairy magic. Trisodium citrate breaks down proteins, letting cheese shreds transform smoothly into dips or sauces. That gooey fondue or stadium nachos owe their irresistible pull to a dash of this unassuming compound. Its role doesn’t stop there. Sliced lunchmeat uses it as a preservative to resist spoilage, reduce the risk of bacterial growth, and keep vibrant flavors intact. Regulations around its use keep food safe and predictable, so folks at home don’t need to second-guess what’s in their deli box or snack pack.
Doctors and nurses recognize trisodium citrate for its role outside the pantry, too. It’s used to make some oral medicines easier on the stomach, taming the burn that can come with certain treatments. Blood banks rely on it for its anticoagulant capabilities. During plasma or blood collection, this compound binds with calcium in the blood, stopping unwanted clotting. That keeps blood products reliable and patients safer during transfusions and surgeries.
Laundry detergent and dishwasher tablets often sneak trisodium citrate anhydrous into their formulas. It softens water, so stubborn stains and grease break down better. Hard water can be a headache, clogging up coffee machines and kettles, not to mention leaving glasses spotty. A sprinkle of this compound helps with mineral build-up, protecting appliances and letting cleaning agents reach their full potential. The struggle with scaling and residue can cost households hundreds every year, so a little trisodium citrate in the right spot saves both money and hassle.
Trisodium citrate gets thorough safety checks. The US Food and Drug Administration lists it as generally recognized as safe for its intended uses. Dieticians and scientists track intake levels and health effects closely. The real challenge lies in modern eating patterns, which rely so much on preservatives and stabilizers. Folks looking for more natural or organic foods sometimes ask if all these additives are necessary. Manufacturers respond by keeping ingredient lists simple when they can, using trisodium citrate only where it really makes foods safer, tastier, or longer-lasting.
There’s still work to do around accessibility and clear labeling. People with dietary restrictions sometimes skip certain foods if the labels seem mysterious. Better education on common additives, what they do, and why they're used could help consumers make smart, confident choices at the grocery store.
People see unfamiliar names in food ingredient lists and instantly wonder about safety. Trisodium citrate anhydrous sounds like something out of a lab, but it shows up in soft drinks, ice cream, and even cheese slices. Food manufacturers use it mainly as a flavor enhancer, preservative, and acidity regulator. So, a typical supermarket trolley contains many products with it inside.
My family loves lemonade and orange sodas, which makes me pay attention to what goes into those bright bottles. Both the United States Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA) review the latest research to make calls on ingredients like this. Both place trisodium citrate in their lists of substances that can be safely added to foods at commonly used levels.
Scientific studies look closely at side effects, absorption, metabolism, and how people’s bodies break down citrate salts. Rats and mice take the lead as test animals in many of these studies, and no evidence has piled up to point to any major concerns in humans who eat reasonable amounts of the compound. Humans actually make citrate in our own bodies as part of normal chemical processes. That means the body can handle small, food-level exposures without trouble.
Some stories about "E-numbers" and synthetic chemicals spark fear online, but the actual number of people who report sensitivity to trisodium citrate is tiny. Most concerns pop up for people with specific health problems—kidney stones or those on special low-sodium diets, for instance. My uncle manages chronic kidney disease, so he watches his sodium intake very carefully. Too much sodium—even from something as plain as table salt—can push blood pressure higher or put more strain on the kidneys.
Everyone wants to know what lands in their dinner. The food industry leans heavily on additives to keep food safe and palatable during transportation. Without preservatives and acidity regulators, products spoil long before reaching grocery shelves. Trisodium citrate acts as a buffering agent, helping certain foods stay stable and tasting fresh.
Most consumers can safely enjoy foods containing trisodium citrate in regular portions. The trick comes down to moderation. Processed foods often contain several forms of sodium, and stacking up these sources over days raises total sodium intake. According to the Centers for Disease Control and Prevention (CDC), Americans, on average, get more sodium than experts recommend. This gets linked to high blood pressure and increased risk for heart disease.
People who watch their sodium—such as those with hypertension, some kidney disorders, or athletes watching hydration levels—should check labels closely. Brands list all ingredients, so spotting trisodium citrate while shopping takes just a second. Looking out for total sodium per serving makes more practical sense than getting caught up in the name of one particular salt.
Cooking at home and eating more whole foods cuts back on both sodium and additives like citrate salts. Fresh fruits, vegetables, and plain proteins rarely carry anything more than what grows from the ground or runs on the farm.
For most in good health, trisodium citrate anhydrous doesn’t raise red flags. Curious eaters, parents, or anyone living with a chronic illness finds peace of mind by seeking out science-backed sources and sticking to balanced diets filled with real foods.
Trisodium citrate anhydrous shows up all over kitchens, even if most folks don’t realize it. I always notice it in processed cheeses and soda cans after reading up on food science during college. It helps cheese melt smoothly and keeps bitterness out of canned drinks. It keeps color and sourness balanced in everything from sparkling water to ice cream. In my home kitchen, powdered sports drinks use it for a pop of tartness and to help powders dissolve without clumps. Food safety regulators like the FDA approve it for adding a bit of sourness, but it doesn’t cover up the original flavors, which lets companies offer fresher-tasting goods.
I first heard about trisodium citrate in a hospital, learning that it’s in many oral rehydration salts. It helps balance electrolytes and can correct mild acidosis, especially in kids hit with dehydration after too much vomiting or diarrhea. Pharmaceutical companies get a reliable acid-base buffer here. Trisodium citrate in blood bags keeps the blood from clotting because it binds calcium. Hospitals rely on it during transfusions, as safe storage of blood wouldn’t work without this salt. Patients in clinics, especially those on dialysis, have also benefited from its ability to keep blood flowing smoothly. Over-the-counter effervescent painkillers use it for fizz and for easier swallowing, too.
People don’t think about what makes their dishwasher or laundry detergent do a better job, but trisodium citrate is a big part of it. Modern detergents need help getting minerals out of water because hard water can mess with soap’s performance. From my time working summers at a laundromat, I saw how water softeners boosted machine life and stains came out easier. Trisodium citrate grabs onto calcium and magnesium in the wash, stopping scale from building up. Clothes come out cleaner, and glasses don’t get that white film. This means less need for harsh chemicals, a win for skin and the environment.
Lab workers keep trisodium citrate bottles close at hand as a go-to for adjusting the pH in test solutions. In the dyeing industry, the salt helps stabilize color and stops unwanted reactions. Water treatment plants turn to it for controlling metal ions, since untreated heavy metals in public water can be serious. In my side project as an aquarium hobbyist, I used trisodium citrate to tweak water hardness for tropical fish—less stress for the fish, fewer losses during transport. Keeping processes controlled, whether it’s textiles, cleaning, or science, has meant real cost savings over time.
With people asking more about greener choices, trisodium citrate rates well as a safer, biodegradable option compared to harsher additives. My conversations with local clean product makers show they like using it because it breaks down more easily. Regulatory groups still keep a close eye on limits and purity, but for many applications, it’s a better option than phosphates or stronger acids, which stay in the environment much longer. So anyone moving toward fewer chemicals in daily life probably already has some trisodium citrate working behind the scenes, making those changes possible.
Trisodium citrate anhydrous appears in everything from food preservatives to laboratory reagents. Folks might glance past the storage details, thinking it’s just another white, crystalline substance. My time in both commercial kitchens and research labs has taught me that proper storage can save a lot of trouble. A product that keeps its integrity becomes a lot more valuable—no one wants wasted batches, unexpected contamination, or even safety issues.
Moisture invites clumping or unwanted chemical changes in powders like trisodium citrate anhydrous. Manufacturers and chemists agree—this compound should always stay dry. Any humidity in the air can trigger caking, reduce flow, or start a slow breakdown. I’ve opened up containers that were shelved carelessly in humid storerooms and found more lumps than powder. Food production and pharmaceutical folks have similar stories. What matters here is storing trisodium citrate in tightly sealed containers. Resealable, airtight drums or bags keep out moisture as much as possible.
The extra step isn’t overkill. In large-scale settings, someone should always label the container with opening dates and keep lids tightly screwed back on. I like to use desiccant packs in the storage bins—especially if the storeroom gets muggy during summer months.
Heat speeds up chemical changes and encourages the growth of molds or bacteria—neither belongs near trisodium citrate anhydrous. Cool, dry, and well-ventilated rooms work best. Anything above room temperature can put the powder at risk. In my experience, a temp-controlled pantry or chemical store, usually about 15°C to 25°C (59°F to 77°F), keeps the compound in proper shape for much longer.
I remember one storage room with a wall next to a boiler room; even though the area passed inspection on paper, the real-world heat always carried through and caused materials to degrade faster than expected. There’s no substitute for checking with a thermometer and moving products as soon as you spot a hot spot.
Chemical compatibility doesn’t always get enough attention. Trisodium citrate anhydrous reacts with strong acids, and corrosion or safety risks can crop up if storage slips. In practical terms, don’t stack it beside cleaning acids, chlorine tablets, or any corrosive materials. My years handling chemicals taught me to segregate incompatible substances with clear physical barriers and labels. If you handle both food-grade and industrial chemicals, separate shelving and locked cabinets spare you from ruin or surprises.
Mistakes happen, especially in busy environments. Good storage practice means marking each container with its contents, date of receipt, and intended use. Any chance for cross-contamination drops when people know what’s what at a glance. I make it a point to inspect stock regularly—old or open containers sometimes bring unwanted guests like dust, pests, or other spillage. If anything looks off—odd smell, color, or texture—just dispose of it safely. There’s no point risking food safety or research results over a few overlooked grams.
Proper storage of trisodium citrate anhydrous keeps quality up and risks down. Education and routine checks go hand-in-hand. Whether you’re using small batches in a restaurant kitchen or handling industrial stock, a little care with containers, temperature, and labels keeps the product safe and effective. It also shows respect for those who work with or consume products made from it.
Walking down the aisles of a food science lab or picking up a chemical catalog, you may spot trisodium citrate on the label—but often, two types sit on that shelf: anhydrous and dihydrate. They come from the same chemical family, both formed from citric acid. Anhydrous means “without water,” while dihydrate carries two water molecules per formula unit.
On paper, both seem interchangeable since they bring the same core benefits—controlling acidity, acting as emulsifiers, and helping stabilize products. Yet if you measure out equal weights, the dihydrate version contains a little less trisodium citrate by mass because of the extra water embedded in every crystal.
I've worked with these in food and pharma projects and found it’s easy to overlook what seems like a small detail. But anybody cooking up formulas, managing shelf life, or costing out ingredients should care about this water content. Manufacturers thrive on consistency. Swapping anhydrous for dihydrate without recalculating dosages can fudge taste, texture, or effectiveness.
For example, if your recipe calls for 10 grams of trisodium citrate, using the dihydrate means you’re getting less of the actual citrate and more water. Substitute blindly, and you’ll throw off the acidity balance of a drink or the melting profile of a cheese sauce. That’s why most product standards list both names and specific amounts. In pharmaceutical labs, the dose has to measure active compounds precisely. That little bit of water packed in every crystal makes the difference between delivering a safe, effective dose or falling short.
Moisture matters for another reason—shelf life and storage. Anyone in humid climates knows how fast salt or sugar can clump. Dihydrate draws and holds more moisture from the air, making it a little trickier for long-term storage, especially where precision counts. Some of my colleagues from tropical regions mention having to take extra care with their ingredient bins, knowing the air can change a powder’s properties over time. Anhydrous, being drier, stays free-flowing longer, giving it an edge for automated processes or large-scale food plants.
Cooks at home likely don’t worry about the hydration state, but once formulas go industrial, the difference feeds into cost calculations and quality management. Getting the hydration right can trim waste, avoid recalls, or keep tastes consistent across batches. Switching from one to the other isn’t just about swapping bags. It takes adjustments to ensure the recipe results hold up.
Those small hydration details can cut deeper in industries like medicine and biotech. The pharmaceutical industry keeps a sharp eye on every stage of a tablet’s life—from mixing to packaging. Even a tiny mistake in hydration accounting can reach as far as regulatory red flags or compromised dosages.
Selecting between anhydrous and dihydrate trisodium citrate is about more than splitting chemical hairs. Every hydration state has strengths for certain uses. Process engineers, pharmacists, and food scientists can avoid headaches and stay compliant by double-checking the exact type of trisodium citrate in hand, doing the math on substitutions, and keeping storage conditions in mind.
Those small differences—just extra water or less—matter every day in real-world production. I’ve seen first-hand how much smoother things go when teams learn these distinctions early. You save money, prevent failures, and guarantee the right results, batch after batch.
| Names | |
| Preferred IUPAC name | Trisodium 2-hydroxypropane-1,2,3-tricarboxylate |
| Other names |
Citrate de sodium Sodium citrate Citrosodine Trisodium 2-hydroxypropane-1,2,3-tricarboxylate Sodium citrate anhydrous Citric acid trisodium salt |
| Pronunciation | /traɪˈsəʊdiəm ˈsɪtreɪt ænˈhaɪdrəs/ |
| Identifiers | |
| CAS Number | 68-04-2 |
| 3D model (JSmol) | ``` data="model load =3dmol; data 'Trisodium Citrate Anhydrous';3D Structure JSmol: [Na+].OC(=O)CC(O)(CC(=O)[O-])C(=O)[O-]" ``` |
| Beilstein Reference | 3602762 |
| ChEBI | CHEBI:61377 |
| ChEMBL | CHEMBL1359 |
| ChemSpider | 7755 |
| DrugBank | DB09183 |
| ECHA InfoCard | 17f16d69-6dfd-443c-a484-ec97c4f9d035 |
| EC Number | 200-675-3 |
| Gmelin Reference | 3797 |
| KEGG | C00735 |
| MeSH | D018437 |
| PubChem CID | 6224 |
| RTECS number | GE8300000 |
| UNII | KST8Q0N1W1 |
| UN number | UN3077 |
| CompTox Dashboard (EPA) | DTXSID8074692 |
| Properties | |
| Chemical formula | Na3C6H5O7 |
| Molar mass | 258.07 g/mol |
| Appearance | White, crystalline powder |
| Odor | Odorless |
| Density | 1.7 g/cm3 |
| Solubility in water | Soluble in water |
| log P | -3.02 |
| Acidity (pKa) | 8.2 |
| Basicity (pKb) | 7.70 |
| Magnetic susceptibility (χ) | -66.0×10⁻⁶ cm³/mol |
| Refractive index (nD) | 1.436 |
| Dipole moment | 0 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 390.8 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | -1568.2 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | -2223.6 kJ/mol |
| Pharmacology | |
| ATC code | B05CX04 |
| Hazards | |
| Main hazards | May cause respiratory irritation. |
| GHS labelling | GHS07, Warning, Causes serious eye irritation. |
| Pictograms | GHS07,GHS09 |
| Signal word | Warning |
| Hazard statements | Not a hazardous substance or mixture according to the Globally Harmonized System (GHS) |
| Precautionary statements | Store in a dry place. Wear protective gloves/protective clothing/eye protection/face protection. If in eyes: Rinse cautiously with water for several minutes. If exposed or concerned: Get medical advice/attention. |
| NFPA 704 (fire diamond) | 1-0-0 |
| Flash point | > 210 °C |
| Autoignition temperature | ~> 745°C (1373°F) |
| Lethal dose or concentration | LD₅₀ (Oral, Rat): 8,000 mg/kg |
| LD50 (median dose) | > 5400 mg/kg (rat, oral) |
| NIOSH | WH7300000 |
| PEL (Permissible) | PEL (Permissible Exposure Limit) for Trisodium Citrate Anhydrous: Not established |
| REL (Recommended) | 5-30% |
| IDLH (Immediate danger) | Not listed. |
| Related compounds | |
| Related compounds |
Citric acid Monosodium citrate Disodium citrate Trisodium citrate dihydrate |
