© 2026 Nanjing Finechem Holdings Co., Ltd,
All Right Reserved
Sodium m-arsenite doesn’t grab headlines like gold or penicillin, but it has held a place in the background of both chemical history and public health debates for over a century. Back in the day, arsenic compounds turned up in unexpected places: weed killers, dyes, wood preservatives, and even some early medicines. Science folk went from marveling at arsenic’s ability to kill pests to fearing its impact on the human body. Sodium m-arsenite branched off from this broader arsenic family. Early researchers explored its chemical quirks and spotted its promise in pest control and lab studies. Once regulations tightened and people learned how arsenic builds up in the body, attitudes shifted for good. Some old texts talk about sodium m-arsenite with a kind of uneasy respect—a compound that delivered results but required care and accountability.
To anyone handling it in the lab, sodium m-arsenite seems straightforward: a bright, crystalline powder, built from sodium, arsenic, and oxygen. But seeing beyond the white granules is important. It’s known in the science world for its reactivity, and there aren't many chemicals like it. Historically, people made use of its solid form because it dissolved easily in water, making it useful for experimental setups as well as chemical production. Sodium m-arsenite goes by different names in the textbooks and the warehouse: Disodium meta-arsenite, Sodium arsenite meta form, or just plain m-arsenite in shorthand by chemists.
Practically speaking, sodium m-arsenite looks like a crystalline solid—sometimes white, sometimes grayish—readily soluble in water with a slightly salty-metallic taste that’s telling on the palate. Its formula (NaAsO2) reflects its simplicity, but that simplicity masks a deep reactivity. Under room conditions, the powder can release toxic arsenic fumes if mistreated or mixed with acids. It forms ions in water, carrying toxicity because of the trivalent arsenic that moves quickly through biological systems. Most chemists keep it in sealed containers, tucked away in lockable cabinets, more for safety than for freshness.
Regulators treat sodium m-arsenite with a heavy hand after decades of hard-earned lessons about arsenic’s toxicity. Modern packaging must state warnings front and center, emphasize purity—usually upwards of 99% for laboratory-grade material—and list its hazards in blunt terms. If you search through a laboratory storeroom, you’ll spot containers marked with toxic and environmental hazard labels, precise chemical formulae, and clear batch numbers. Labs keep digital logs and old-fashioned ledgers to track every gram.
Manufacture sticks to established chemistry: sodium carbonate (or sometimes sodium hydroxide) reacts with arsenic trioxide in water to generate sodium m-arsenite. The resulting mixture needs cooling, filtration, and careful drying. This reaction doesn’t demand exotic equipment, just immense care in venting fumes and collecting wastes. Anyone who’s spent time in a synthesis lab knows to avoid the dust, double-check the vent hoods, and hold respect for arsenic’s reputation of being both useful and deadly. There’s little room for shortcuts, and waste gets collected separately for hazardous disposal, not just tossed down the drain.
Sodium m-arsenite serves as a stepping stone for many other chemicals, either by oxidation to pentavalent arsenates or by reduction and combination with organic groups. In academic settings, it acts as a starting material for organoarsenic compounds, which played roles in antiprotozoal medicines and chemical warfare research before better options came around. It reacts in strong acids, releases toxic arsenic gases, and combines with other salts to form a range of derivatives. Each of these routes demands tight controls, and accidents have taught universities and companies to seek alternatives whenever possible.
This compound travels under several aliases, which has added confusion for those tracing toxic exposures or comparing research reports. For those in chemical supply, you’ll see the labels “Disodium meta-arsenite,” “Sodium orthoarsenite,” and CAS number 7784-46-5. These names reflect slightly different atomic arrangements or traditions in naming, rather than true chemical differences. Regulatory bodies often consolidate under the name sodium meta-arsenite to help with tracking and safety protocols.
Young researchers get an earful about sodium m-arsenite’s hazards during lab safety training, and for good reason. Inhalation, skin contact, or ingestion can lead to severe health consequences, including nerve damage, organ failure, or cancer. Handling rules don’t leave much wiggle room: nitrile gloves, splash goggles, and fume hoods aren’t up for debate. Institutions require spill kits and emergency procedures, and there’s no shortage of signs or checklists nearby. Drinking or eating anywhere near sodium m-arsenite earns sharp warnings. Medical monitoring and exposure limits (like OSHA or ACGIH standards) guide workplace controls, reflecting a long record of occupational illness cases. Safe disposal remains a priority, with strict rules against dumping down regular wastewater lines.
Many of sodium m-arsenite’s old uses have faded for good reason. Early on, it found a niche in herbicide formulas, insecticides, and even veterinary solutions. Most countries now restrict or ban such use, turning mostly to tightly controlled laboratory work. Some research groups use sodium m-arsenite to study stress responses in plants, yeast, and animals because it rapidly disrupts cells, mimicking heavy metal poisoning. In biomedical research, it acts as a model toxin for exploring cell signaling, apoptosis, and detoxification pathways. These studies run under close supervision, usually with alternative compounds at the ready for less risky experimentation. Industrially, only a handful of niche applications hang on, sometimes in mining, metallurgy, or analytical chemistry labs that have strict oversight.
Research on sodium m-arsenite constantly circles back to understanding toxicity, metabolism, and remediation. Scientists use it to unravel how arsenic binds to proteins, disrupts DNA repair, and triggers programmed cell death. Researchers experiment with forms that can be traced in living organisms, applying molecular biology techniques and advanced imaging. Some groups dig into the puzzle of why certain plants survive arsenic soil contamination, testing genetic tweaks using sodium m-arsenite as a stressor. Meanwhile, interest grows around finding safe ways to neutralize or convert arsenic waste through newer remediation agents, bioaccumulation, or nanotechnology.
Health concerns have shaped nearly every guideline, leading to deep studies on sodium m-arsenite’s effects over time. Repeated exposure links to skin, lung, liver, and cardiovascular diseases, and there’s no shortage of data from old poisoning cases tied to contaminated drinking water or industrial sites. Epidemiologists and toxicologists use sodium m-arsenite as a benchmark, comparing biomarkers in cells and living animals to see how the body reacts. Research extends to possible links with immune suppression, impaired child development, or even links to specific cancers. There’s urgency in studies aiming to lower exposure in at-risk populations, especially in regions struggling with arsenic-laced groundwater. For most labs, the only ethical choice is to use the smallest amounts feasible and double down on strict controls.
Looking ahead, sodium m-arsenite's days as an industrial workhorse appear numbered, but its research value hasn’t faded. New generations of scientists tackle its impact using tools like CRISPR for genetic screens or nanotech for cleanup. Instead of using it as a bulk product, labs rely on it for highly targeted studies. The big opportunity lies with cleanup: removing arsenic from contaminated soils and waters. Science teams continue to explore bioremediation, using engineered microbes and plants that can soak up or degrade arsenic. Tightened laws mean sodium m-arsenite is unlikely to return as a garden chemical or household product. These shifts show how public health, environmental awareness, and scientific progress keep the focus on managing risk, not just chasing convenience. The story of sodium m-arsenite reminds us of the value of vigilance—both in what we use and in what we leave behind.
Sodium m-arsenite stands out among specialty chemicals because of its history and unique applications. Most people have never heard of it, but those who have worked in chemistry or older industries know it as a strong arsenic compound. For decades, its roles drifted between textiles, agriculture, and laboratory research.
Arsenic brings up strong feelings and with good reason. Exposure to these compounds brings major health risks, including cancer, organ damage, or neurological symptoms. So anyone coming in contact with sodium m-arsenite, even by accident in an old lab or manufacturing site, should know the risks and protections.
Decades ago, this substance had a reputation for fighting off insects and fungi in cotton, grapes, and other crops. Farmers appreciated its power against threats that could wipe out fields. It worked by disrupting vital processes in pests and bacteria—this made it a go-to solution for stubborn outbreaks. But with time, its downsides came into sharper focus. Films of arsenic would linger in the soil, unfinished and risky long after the harvest. These residues easily leached into groundwater or built up in produce. Public health studies eventually showed links between exposure and chronic disease.
Efforts from environmental agencies turned the tide. Governments around the world set tight rules. In the US, the EPA phased out many uses of sodium arsenites due to their toxicity. Once researchers understood the long-term risks, safer alternatives became the new standard for crop protection.
Older dye houses and pigment factories leaned on sodium m-arsenite for certain colors and processes. Its chemistry allowed manufacturers to fix dyes to fibers, creating shades that didn’t fade with simple washes. Some specialty glassware production also required arsenic-based chemicals to achieve special finishes. Stories from retired workers remind us how handling these vats brought split-second decisions—one slip could mean exposure.
Now, rules about worker safety and environmental limits shaped new ways of making colorants. Modern color chemistry found better fixes that kept toxicity low. Historic samples still show up in old buildings, which sometimes sends specialists in with hazmat suits before renovation work. Nobody likes to worry about unseen dangers on the job.
Scientists still rely on sodium m-arsenite for highly controlled experiments. It acts as a source of trivalent arsenic, which researchers study for its effects on cells or genetic material. Studies involving oxidative stress and epigenetics, for example, use this compound to push biological systems and map out damage pathways.
Lab safety today revolves around containment and direct supervision. Special cabinets, respirators, and rigorous disposal routines help keep the risks away from homes and communities. It struck me, the first time I worked with arsenic, how much protocol matters. One careless move would erase the safety margin everyone depends on.
With everything we know now, the world doesn't take sodium m-arsenite lightly. Banning its field use forced better alternatives and heavier focus on protective equipment. Cleanup efforts at contaminated sites continue, and chemical producers track every ounce. Education remains the strongest tool—nobody should handle a compound like this without knowing the stakes. Research into arsenic’s effects on the body also means better screening for those exposed.
For anyone in chemistry or site management, staying current on legacy chemicals lets us avoid repeating past mistakes. Tracing old uses and updating protocols leaves fewer holes for accidents or health problems to slip through.
Sodium m-Arsenite has a reputation that keeps lab workers on their toes. People talk about explosive chemicals, but this arsenic-based compound causes a different kind of worry. Breathing, touching, or even a splash in the eye—small encounters can bring big health problems. Chronic exposure has links to cancer, nerve damage, and other nasty effects. The dangers don’t just touch the person handling it, either. A single mistake can spread traces into the workplace, dragging risks to colleagues down the hall.
Years ago, I worked next to the toxicology lab at a university. Strict rules hung on every wall for a reason. One careless student handled an arsenic compound with only nitrile gloves and later touched their face. Even in a highly-trained group, one shortcut led to the hospital and a stern warning for us all. That day burned in my memory—the cost of a simple mistake with this class of material.
Reliable personal protective equipment comes first. Always put on sturdy gloves—double glove with latex over nitrile for extra security. Wraparound safety goggles keep splashes away from the eyes. A tightly buttoned lab coat with long sleeves, closed shoes, and even a face shield for weighing powder build a solid barrier. Good ventilation matters. Fume hoods aren’t suggestions; the cap stays down during weighing and transfers, with the airflow humming. If the air smells, something’s wrong—step back and fix it.
Opening a bottle or transferring sodium m-Arsenite never happens outside these protective setups. Don’t handle it alone. If exposure happens, emergency eye wash stations and showers save skin and eyes from further harm—knowing their location becomes part of the plan.
Keep messy benches far away. Use absorbent liners and work only over trays designed to trap spills. These measures feel strict, but even tiny crystals sticking to surfaces can contaminate hands or food. Hand washing becomes second nature—soap and water after every encounter, even if gloves stayed on. No food, gum, or drink gets past the threshold in arsenic workspaces.
Regular trash cans don’t cut it. All solid and liquid waste goes straight into clearly labeled arsenic waste containers. Double-bag items and use rigid, puncture-resistant bins. Disposal waits for collection by specialists who follow strict hazardous waste routes. Drain disposal puts not just your lab, but your whole community at risk—resist cutting corners.
Comprehensive training saves more people than any glove or mask. Teams run through potential accident drills, from minor skin contact to major spills. Survival in a busy lab doesn’t rely on luck. Respect for sodium m-Arsenite grows from in-depth understanding, not just a list of do’s and don’ts.
Sodium m-Arsenite rarely causes disaster overnight. Troubles creep in through forgotten residues or ignored warnings. No one wants to see a friend or coworker become a case study. More than any equipment or lab coat, it’s the daily habit of looking out for each other that keeps a workplace safe. With experience comes a kind of stubborn caution, the knowledge that health is worth more than saving a minute or skipping a step.
Sodium m-arsenite, which shows up with the formula NaAsO2, often gets lost in the crowded world of inorganic compounds. Some folks shrug off chemical specifics, but these details matter, especially with something as potent as arsenic’s sodium salt. The chemical structure shows arsenic at the center, bonded to two oxygens and a single sodium ion. The “m” in the name points to the meta position, a way chemists highlight which oxygen atoms stick to the central arsenic within the oxyanion group.
Sodium m-arsenite’s atomic arrangement isn’t about trivia. Its makeup affects toxicity, solubility, and how it acts in real-world settings. Sodium hooks up with the arsenite ion, making a salt that dissolves fast in water. The link between arsenic and oxygen opens doors and also raises red flags — what works as a preservative or pesticide can bring steep health risks if handled wrong. This knowledge means clearer labels, tighter controls, and smarter choices among regulators and end users.
Professionals who’ve seen the impact of arsenic poisoning don’t take chemical forms for granted. Environmental scientists, for example, run into sodium m-arsenite in groundwater, especially near mining or industrial operations. Arithmetic formulas stay on paper; in the wild, these compounds alter lives. The AsO2− ion can cross biological membranes, disrupt enzymes, and, at high enough doses, trigger severe health effects. The reason boils down to how arsenic bonds with oxygen and how sodium amps up solubility.
Factories and researchers stick around the sodium arsenite family for wood preservation, dyes, and pesticides. Choices depend on structure. The m-arsenite form matches a specific pattern of atoms. If buyers or users don’t check the label or understand the difference between ortho- or meta-arsenites, mistakes follow. This isn’t just a chemical naming issue — it’s about safety, product performance, and legal compliance. Fast-acting forms speed up both benefits and risks, especially when residues end up in soil or waterways.
In my own experience, teaching students about sodium m-arsenite’s formula and structure goes well beyond memorizing symbols. It’s about sketching out the AsO2− ion on the board, tracing the single sodium cation off to the side, and talking through the implications. Questions fly in: Will it break down under light? Can bacteria turn it into something more toxic? Who monitors its movement through soil? The answers often circle back to structure — not just that there’s arsenic, but how it’s arranged.
Addressing real concerns means pushing for better monitoring and clearer communication. Water districts invest in sensitive tests that pick up traces of sodium m-arsenite, not just total arsenic. Labels must spell out the risks, not just for workers in protective gear but for families down the street. In labs, researchers map out how chemical tweaks might lower toxicity or lock arsenic into safer forms. These steps chip away at risks while holding onto the functional value of sodium m-arsenite in needed applications.
Getting specific about sodium m-arsenite’s formula and structure cuts through confusion and drives home the point: with this chemical, as with many others, the details steer both science and responsibility.
Sodium m-Arsenite doesn’t read like a benign name on a safety sheet. Arsenic compounds carry a track record for toxicity. There’s a reason plenty of labs ban its use unless work absolutely demands it. The powder easily contaminates air and surfaces. Gloves and goggles aren’t just decorations for the safety poster; they protect lab folks from skin burns and severe respiratory trouble. Once, during a stint as a chemical stockroom manager, a single spill triggered an evacuation—the sharp, metal tang caught even through fitted masks. This stuff won’t forgive a slip.
Sodium m-Arsenite sits in the class of chemicals calling for locked, airtight storage, away from curious hands and food prep spaces. On shelves, clearly labeled glass or high-density polyethylene containers work best. Sturdy seals keep out humidity and prevent vapors from escaping. Every container needs a warning label: “Toxic—Arsenic Compound.” In practice, storing it next to acids or oxidizers walks a riskier path. Once, a neighboring bottle of acid cracked, and only luck stopped a dangerous fume-out. Segregation matters—assign separate cabinets, ventilation, and inventory logs, always under strict key-card or sign-out control.
Pouring this stuff down a drain is not an option. Municipal wastewater plants were never designed for arsenic-laden runoff, so dumping small amounts snowballs into serious local water contamination. On the job, I called credible hazardous waste disposal firms, the types qualified to handle regulated poisons. Those companies treat arsenic with iron salts, lock it in concrete, or burn residues at authorized toxic waste incinerators. It costs more up front but avoids regulatory trouble and community health scares. The EPA, CDC, and OSHA list arsenic waste as acutely hazardous, with legal teeth to punish shortcuts.
Families live near universities, research parks, and old manufacturing sites. Even trace arsenic leaks show up in groundwater years later. Where I lived in northern New Jersey, an abandoned plant’s lazy disposal habits left decades of polluted soil—parents afraid to let kids dig in their own backyards. Responsible stewardship doesn’t just shield the workplace; it ripples downstream into the community. Regular audits, real spill kits, and annual safety drills help keep complacency at bay.
Fewer workplaces need Sodium m-Arsenite now, thanks to safer alternatives and digital modeling that replaces some traditional experiments. Labs phasing out stocks work with hazardous material companies to safely transport and destroy leftovers. Smart operations also partner with university extension programs for custom disposal workshops, sharing knowledge across departments. Even small steps—like signing safety pledges or reviewing MSDS sheets before order requests—go a long way.
In my time around chemicals, I learned that safety isn’t just a checklist—it's about looking beyond the bottle and seeing how choices affect coworkers, neighbors, and the next person opening that storage cabinet. Clear rules, honest training, and zero shortcuts make a real difference in keeping Sodium m-Arsenite where it belongs: under lock and key, and eventually, out of the reach of water, soil, and unsuspecting hands.
Sodium m-arsenite isn’t something a person stumbles on during a grocery run. For the most part, it turns up in chemical labs or industries where its properties matter for specific uses. Its formula, NaAsO2, means it includes arsenic. Most people wince when they hear “arsenic,” and for plenty of good reasons. Arsenic brings a long history of causing health scares. The stuff gained a dark reputation as a poison generations ago, but its modern forms have a way of slipping into water and soil, quietly creating problems.
Breathing, swallowing, or even touching sodium m-arsenite invites direct harm. Once it crosses into the body, it gets to work interfering with cell function. This interferes with enzymes the body uses to keep almost everything moving. In people, this can cause stomach pain, vomiting, and diarrhea. Exposure over months or years links strongly with cancers of the skin, lungs, and bladder. The International Agency for Research on Cancer gives arsenic compounds a clear stamp as a human carcinogen, not just a “maybe.” The World Health Organization draws a hard line on safe exposure—setting drinking water limits to 10 parts per billion.
Personal experience in industrial safety drills showed just how seriously even trace amounts get treated. Staff in protective gear, regular air monitoring, and rigid rules for storage made a real impression. No one working around sodium m-arsenite shrugs it off as an everyday chemical. Instead of focusing just on short-term symptoms, many safety officers emphasize delayed effects: a cough might fade, but cellular changes may not show up until years later.
Sodium m-arsenite brings a special threat to water and soil. In water, it doesn’t break down: it hangs around, seeps through soil, and moves into rivers or lakes. Fish and wildlife take in the toxin, where it moves up through the food chain. People living near old mining sites or places that once used arsenic-based pesticides know the long shadow these compounds can cast. Arsenic’s persistence in the environment means cleaning up spills or legacy contamination costs millions and takes decades, often still leaving traces behind.
My experience hiking near old industrial sites brought this home: signs along the paths warned hikers not to drink from streams or picnic too close to the banks. Arsenic doesn’t always show itself, but its residue lingers, affecting not just people but animals and plants in the area. In regions with arsenic-laced groundwater, studies tie exposure to everything from declining crop yields to increased rates of serious illness.
Chemicals like sodium m-arsenite don’t slip into daily life by accident. Use comes with strict rules. Industry sets up closed systems, air filters, and waste-handling routines. Safe alternatives exist in some cases, which can chip away at dependence. Researchers keep looking for better ways to clean up contaminated soil and water. Phytoremediation, which uses plants to pull arsenic out of the ground, shows promise for small sites but needs more work on a bigger scale.
People living near known arsenic sources push for better water testing and more public warnings. Governments put money into cleanup and encourage industries to switch to less toxic alternatives. For those working with sodium m-arsenite, constant training and strict safety checks shape every shift. The risks stick around. Careful management and substitution could keep dangers from spreading further.
| Names | |
| Preferred IUPAC name | Sodium 3-arsenite |
| Other names |
Sodium meta-arsenite Sodium arsenite Disodium arsenite |
| Pronunciation | /ˈsəʊdiəm ɛm ɑːˈsɛnaɪt/ |
| Identifiers | |
| CAS Number | 7784-46-5 |
| 3D model (JSmol) | `"3D model (JSmol)": "As([O-])([O-])=O.Na"` |
| Beilstein Reference | 80328 |
| ChEBI | CHEBI:76244 |
| ChEMBL | CHEMBL1231347 |
| ChemSpider | 12422 |
| DrugBank | DB11538 |
| ECHA InfoCard | 100.013.874 |
| EC Number | 12044-56-1 |
| Gmelin Reference | 10734 |
| KEGG | C01838 |
| MeSH | D013937 |
| PubChem CID | 11348 |
| RTECS number | CY7175000 |
| UNII | 0C99V6L998 |
| UN number | UN1586 |
| Properties | |
| Chemical formula | NaAsO₂ |
| Molar mass | 163.911 g/mol |
| Appearance | White crystalline powder |
| Odor | Odorless |
| Density | 2.87 g/cm3 |
| Solubility in water | Soluble in water |
| log P | -4.18 |
| Vapor pressure | Negligible |
| Acidity (pKa) | 12.1 |
| Basicity (pKb) | 6.0 |
| Magnetic susceptibility (χ) | -41.5e-6 cm³/mol |
| Refractive index (nD) | 1.500 |
| Dipole moment | 1.76 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 151 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | -643.98 kJ/mol |
| Pharmacology | |
| ATC code | V03AB06 |
| Hazards | |
| Main hazards | Toxic if swallowed, inhaled, or in contact with skin; may cause cancer; causes damage to organs; very toxic to aquatic life. |
| GHS labelling | GHS06, GHS08 |
| Pictograms | GHS06,GHS08,GHS09 |
| Signal word | Danger |
| Hazard statements | H300 + H330: Fatal if swallowed or inhaled. H310: Fatal in contact with skin. H410: Very toxic to aquatic life with long lasting effects. |
| Precautionary statements | P260, P264, P270, P271, P273, P280, P284, P301+P310, P302+P352, P304+P340, P308+P313, P314, P320, P330, P361, P403+P233, P405, P501 |
| NFPA 704 (fire diamond) | 3-3-2-ACT |
| Autoignition temperature | > 400 °C (752 °F) |
| Lethal dose or concentration | LD50 (oral, rat): 15 mg/kg |
| LD50 (median dose) | 20 mg/kg (rat, oral) |
| NIOSH | TD0125000 |
| PEL (Permissible) | PEL (Permissible Exposure Limit) of Sodium m-Arsenite: 0.01 mg/m³ (as As) |
| REL (Recommended) | 10 mg/kg |
| IDLH (Immediate danger) | 5 mg As/m³ |
| Related compounds | |
| Related compounds |
Sodium arsenite Arsenous acid Sodium arsenate Arsenic trioxide Potassium arsenite |
