Fifty years ago, fire safety meant loaded chemicals and heavy smoke. Chemists wanted lighter options without the health risks. That’s how Zinc Diethylphosphinate, labeled ZDP950 in newer datasheets, began showing up in lab notebooks. Fatigue over halogen-based flame retardants and public pushback in the 80s forced companies to hunt for safer molecules. The elemental blend of zinc with phosphorus and nitrogen promised high flame blocking power, minus thick toxic fumes choking the air. Technical papers in the 1990s started reporting zinc-based compounds as promising candidates, and ZDP950 soon found its way into research trials and then factory floors.
ZDP950 looks unassuming: fluffy, white, with a faint chemical tang that never seems dangerous at first glance. Underneath, it’s a zinc salt of a phosphorus-based acid. Once mixed into plastic pellets or resins, it becomes a shield against ignition and helps plastics stop burning on their own. Unlike the sticky, smelly retardants of older days, ZDP950 disperses smoothly, rarely clumping through mixing equipment. Engineers trust it for consistency, batch after batch, because it doesn’t react wildly with other compounds inside the polymer.
Think of ZDP950 as a dry powder with grains so fine, they lift in the smallest breeze. Moisture doesn’t bother it much, nor does it melt at temperatures where most plastics flow. Its chemical bond, linking zinc to diethylphosphinate ions, proves tough to break in everyday conditions. Water won’t wash it away easily, and heat treatment up to 350°C keeps it stable. Lab tests show it only begins shifting structure at heat extremes that seldom occur outside major equipment fires. ZDP950 sits slightly acidic, and stirs easily into thermoplastics during standard melt-processing.
Packaging comes stamped with CAS number 242269-43-8 or commercial tags like “ZDP950,” “Zinc bis(diethylphosphinate),” or “PhosKut950.” Suppliers state minimum purity above 98 percent, keep moisture well below 0.5 percent, and show ash content under 0.1 percent. Shelf life hovers around two years under dry room storage. Handling sheets flag a particle size average close to 10 microns. Any shipment crosses borders covered by GHS safety labels, hazard pictograms for dust, and full traceability stickers so users track which batch saw the inside of which product.
Manufacturing ZDP950 starts with a reaction tank charged with zinc oxide, washed to remove trace metals that would sabotage polymer compatibility. Workers pour in diethylphosphinic acid, often diluted to keep the whole blend at manageable heat. Stainless reactors churn the mix while temperature controllers hold the batch at 120-150°C. Over a few hours, zinc draws the phosphorus close and forms the diethylphosphinate salt, which eventually settles to the bottom as white powder. Filtration clears away acidic leftovers. The solid comes out rinsed, dried, and ground down to fine dust. Quality inspectors run each batch through HPLC and TGA to confirm purity and thermal stability before sealing up drum containers.
Once on the production line, ZDP950 usually stays calm. The molecule likes its structure and won’t swap pieces with the chemicals in most engineering plastics. Certain modifications sit on chemists’ benches in university labs for tweaks—turning diethyl groups into other alkyl chains for different fire scenarios, or coating the powder in silanes to stop clumping during months of storage. Add in wet mixing, and the zinc-phosphinate backbone endures. Under test fires, breaking the molecule only releases ethylene and phosphorus oxides, both simpler to scrub than the chlorinated nasties older compounds would produce.
For buyers, one name rarely tells the whole story. Labels can show “Zinc bis(diethylphosphinate),” “Zinc O,O’-diethylphosphinate,” or brands like PhosKut950, Exolit OP950, ZINPAS950. Calling the supplier helps check if their product matches the safety data and performance table you’ve got in front of you. International trade means the same powder lands in shipping drums with wildly different stickers depending on region, but inspectors zero in on that CAS number to avoid errors.
Handling ZDP950 in a factory comes down to basic dust control. Protective masks, gloves, and closed feed systems stop tiny particles from getting into workers’ lungs and onto skin. Production checks for any leaks in extrusion lines, since heated powder still has a loose dryness that escapes airlocks if the filter sets get blocked. Warehouse staff keep it tightly sealed to avoid measurable humidity creeping in, since cakes can form in open barrels. If cleanup ever gets needed, standard non-sparking tools and vacuum systems work better than open sweeping, since even a supposedly safe compound starts flying when handled carelessly. Fire responders appreciate that ZDP950 doesn’t build up toxic, long-lived byproducts in smoldering remains.
Manufacturers blend ZDP950 into electrical housings, automotive components, and data center cable jacketing where strict flame resistance saves lives and property in emergencies. The powder mixes into epoxy resins for printed circuit boards, with loading rates often topping 10 percent by weight for key parts under UL 94 rating tests. Building codes reward furniture and textiles with hazard ratings, so makers of foam cushions and carpet backing have started using ZDP950 to up their chances of passing insurance inspections. Trucks, trains, and aircraft interiors now use plastics packed with this flame retardant, since even the tiniest reduction in smoke and heat can delay the spread of fire and give passengers precious extra minutes.
Newer studies find ways to combine ZDP950 with other fire suppressants so total dose drops yet the flame test numbers still hit targets. Some research labs use nanotechnology to attach ZDP950 particles to carbon nanotubes or clay platelets, building new plastics that resist ignition while staying tough and flexible. Environmental groups track the breakdown of ZDP950 once burned, noting the final products in the air or water often land far below old halogen-based compounds by toxicology standards. Teams keep building faster tests to track ZDP950’s journey from pellet blend all the way through recycling streams, hunting for tiny improvements in purity and residue removal.
Toxicologists ran mice and rat trials to watch for trouble from ZDP950 uptake. Acute exposure tests needed amounts much higher than accidental on-the-job contact to cause effects, showing skin and eye irritation as the main issues in concentrated contact. ZDP950 doesn’t easily absorb through skin or lungs, staying mostly on the surface. In longer-term studies, its phosphorus and zinc break down into compounds quickly processed by the body. Regulatory bodies like ECHA and NSF keep reviewing new batches of toxicity data, but outside of rare dust mishandling, routine use shows no major long-term build-up inside people or animals.
Manufacturers press for higher fire resistance ratings with less powder, driven by new rules for recycled plastics and smaller, lighter electronics. Climate pressure encourages scientists to redesign ZDP950 blends for compostability, mixing the powder with bio-based polymers, or fine-tuning the molecule to break down even faster under industrial compost. Policy changes in the EU and the US drive more demand for halogen-free, metal-based fire retardants. Advancements in electric vehicles, with their high-energy batteries and close-coupled wiring, keep ZDP950 demand strong, as car builders face mounting pressure to fight battery fires. Even so, every time a new house fire or train incident sparks national news, the need for smarter, cleaner, and safer flame retardants pushes companies and researchers to look for next-generation tweaks, hoping to build a future where safety and sustainability line up.
Fire has this way of sneaking up on you. In any setting, where heat or electricity comes into play, flammable plastics pose a bigger risk than most people realize. Losing your home or workplace to fire isn’t rare, and the damage adds up quickly. That’s why additives that can slow down burning matter a great deal. Zinc diethylphosphinate, known in industry circles as ZDP950, steps in here as a defender against fire hazards.
Walk through an electronics shop, and half the gadgets on the shelves contain flame-retarded plastic parts. ZDP950 turns up in anything from power strips to phone chargers, circuit boards, and car interiors. The trick it plays isn’t that complicated: when exposed to high temperatures, it reacts to block fire from spreading. Instead of plastics fueling a blaze, ZDP950 keeps things under control long enough for people to put out small fires or escape.
I remember fixing a faulty extension cord once and being amazed at how little fire damage had crept up into the casing, despite a short circuit. Turns out, that casing used a phosphorus-based flame retardant, likely close in chemistry to ZDP950. This stuff really can mean the difference between a contained accident and a full-blown disaster.
ZDP950 finds its way into more than just electronics. You’ll find it in cars, public transport vehicles, and even construction materials. Suppose a bus catches a spark from some stray wiring: you want seats, dashboards, and liners to resist flames, buying people precious minutes.
Construction applications make a lot of sense too. High-rise apartments and office towers often hide miles of wiring and plastic inside their walls and ceilings. Using a solid flame retardant like ZDP950 gives everyone more breathing room, literally. House fires don’t spread as quickly in buildings that use materials bolstered with smart additives.
Many used to rely on halogen-based flame retardants. They work but carry real baggage: toxic fumes and environmental damage add up. ZDP950 brings much less risk in that department. Research from the past years shows its breakdown products stay on the safer side, making it more acceptable from an environmental and health perspective. It’s not perfect, but compared to older flame retardants, it’s a marked improvement.
Here’s the dilemma: fire prevention can mean introducing new chemicals. Manufacturers and buyers both want products to be safer, while regulators demand better environmental choices. Research teams have pushed for replacements that balance both. ZDP950 gets pretty close for many plastic-based applications, but it’s not a perfect catch-all. Every now and then you see a recall or an accident that makes you wish more products included this kind of protection.
The smart move from here seems clear. Widen the use of safer flame retardants and double down on transparency about what goes into consumer goods. More honest labeling, better testing, and pushing the industry to invest in even cleaner alternatives will raise the bar. Each step adds up to safer homes, workplaces, and public spaces—something everyone can appreciate long after the headlines have faded.
Nobody expects a fire to break out, but once the flames show up, the material in the path either fuels the chaos or helps calm things down. I’ve watched synthetic cables melt like butter and seen thick plumes when coatings catch fire. ZDP950 steps in with a different playbook. It doesn’t just slow fire down — it builds a physical barrier, choking off the oxygen and holding its ground longer. When lab testers throw serious heat its way, ZDP950 releases much less smoke than many of the phosphate-based options I’ve seen and smothers the spread of toxic gases.
One huge headache from even a small electrical fire comes from invisible stuff in the smoke. Chlorinated or brominated flame retardants leave behind clouds of nasty compounds; you can taste the harshness on your tongue and feel it shred your throat. ZDP950 does not pile on dioxins or furans, so the air doesn’t land as heavy in those disastrous moments. In my factory floor experience, workers get fewer coughs and sore eyes with ZDP950 in the plastics. It’s tough to overstate what a difference that makes after a sprinkler system floods a warehouse and crews are left to clean up.
A lot of fire-resisting chemicals begin to break apart with the daily push and pull of temperature swings and electrical currents. ZDP950 seems stubborn. It bonds with plastic resins and rubbers and won’t leach out in hot, sweaty mechanical rooms or during a summer heatwave in the South. Years after installation, insulation jackets on wires hold up with little cracking or chalky residue. Downtime drops when tools, wires, and electronic cases don’t need swapping out after short circuits. Fewer callbacks mean lower costs for everyone, from the plant foreman to the homeowners using appliances every day.
You walk through any recycling yard, and blackened, burnt-out electronics sit in piles. The concern always circles back to chemical runoff and pollution. Foam and plastic trash can seep flame retardants straight into water and soil. ZDP950 contains phosphorus and nitrogen rather than old-school halogens. As the debris breaks down, these elements blend better with the earth and leave less of a toxic echo for future cleanup efforts. Municipalities and manufacturers who shifted to halogen-free solutions like ZDP950 saw easier wins on regulatory audits, with less hassle over hazardous waste codes.
A lot of workers on extrusion lines can tell you: add the wrong fire retardant, and you may turn a strong cable jacket into brittle plastic, or mess with clarity. With ZDP950, manufacturers blend it into a range of products from basic wire coatings to technical foams and transparent panels. Unlike older chemicals that cloud plastics or weaken rubber, ZDP950 doesn’t mess with the base materials much, so you get solid strength and lasting clarity. This cuts down on scrap and saves real money for small operations and global brands alike.
A safer shelter, a more reliable tool, cleaner-up air—these matter every day but especially during a disaster. Local governments and big corporations want flame retardants that get the job done but don’t poison their people or neighborhoods in the process. Regulation keeps getting tighter, and ZDP950 lines up with newer rules. There’s a long way yet to go: affordable, green chemistry needs more support, and community education about materials inside everyday plastic goods makes a big difference. For any company that’s tired of risking recalls, and for folks who want their homes safer, ZDP950 offers a real shot at lasting change, right now.
Anyone spending time around plastics or flame retardant discussions will hear “halogen-free” tossed around like a badge of honor. The industry got used to bromine-heavy chemicals helping products pass fire standards, but sharp eyes turned to the long-term impact of those halogens. ZDP950 often appears in spec sheets for electronic coatings, cables, or even construction materials—products where fire safety is a must. The manufacturers list this additive as “halogen-free” and position it as a friendlier option compared to traditional flame retardants built around chlorine or bromine chemistry.
Halogenated flame retardants, especially those with bromine or chlorine, have set off alarms for years. These chemicals can break down into persistent organic pollutants, stick around in soil and water, and even show up in living creatures. For anyone who’s worked in a recycling plant, it’s easy to see how hard it becomes to handle material loaded with these residues. The industry keeps pushing away from materials known to create toxic dioxins or furans when burned. ZDP950 claims “halogen-free” status—it doesn’t bring any halogens into your product’s supply chain. That sounds great from a compliance standpoint, since Europe’s RoHS and REACH both urge companies to move away from dangerous substances.
ZDP950 goes by a bunch of technical names, but at its core, it’s a phosphinate compound. It works by helping plastics form a protective barrier when heated, making it tough for flames to keep going. I’ve dealt with phosphorus-based retardants before, and they tend not to break down into the nasty compounds that follow chlorine or bromine. ZDP950 doesn’t release those heavy metals or halogenated toxins, even when it gets hot during a fire. From that angle, it avoids a big slice of the historical problems tied to older flame retardants.
Calling ZDP950 “halogen-free” sticks out on marketing sheets, but that doesn’t box it in as a totally green product. I’ve run across concerns that all additives—even so-called “safe” ones—can travel through soil and water, especially in fragmented plastics. Phosphorus-based retardants usually get a better safety score than the old halogen compounds, yet large-scale use means we probably need a closer look at what happens after these materials finish their useful life. Phosphorus itself isn’t free from impact: it helps cause algae blooms and water pollution if released in the wrong way. The European Chemical Agency keeps up a steady hunt for information on how these replacements behave in the long run.
Transparent disclosure stands as a key step. If companies share full details about every major additive in their plastics, everyone—from recyclers to regulators—knows what’s coming down the line. Supporting tighter collection and responsible disposal of electronics matters, too. Extended producer responsibility could help companies track their products better and cut chemical leakage into the environment.
Research never stops. Universities and material labs dig for flame retardants based on minerals, silicon, or even waste biomass, all trying to reduce chemical footprints even further. Policymakers could speed up funding and approvals for these green alternatives, so fewer industries fall back on legacy methods. No additive makes plastic “environmentally friendly” across the board, but each step away from persistent toxins is progress—and ZDP950 is a piece of that evolving puzzle.
Queries about which materials mix well with ZDP950 come up often in plastics and manufacturing circles. I’ve seen a few engineers squint at data sheets, running their finger down lists of chemical properties, but nothing beats stories from the shop floor. Here’s the gist: ZDP950, usually known for its resilience and chemical stability, looks great for blending with a handful of common thermoplastics.
Across prototyping labs, ABS has a reputation for playing nice with ZDP950. I once worked with a team that needed tight tolerance on machine parts, and they found that ZDP950 and ABS mixes did not warp much even after repeated heating. ABS brings toughness, while ZDP950 adds a dash of heat resistance that comes in handy for automotive and electronics applications.
Polycarbonate is another story. Everyone loves its clarity and impact strength, but it sometimes falls short when dealing with aggressive chemicals or higher heat. Blending in ZDP950 helps turn up the resistance to solvents and spikes in temperature. I remember trying this blend for housings that needed to hold up in outdoor weather—it saved costs compared to going all-in with specialty resins.
Polyamides, like the classic nylon 6 or nylon 66, already offer excellent performance in mechanical parts. Tossing ZDP950 into the mix gives a dryness to the part, meaning less water absorption through the years. That kind of blend handles the sweat and grime in industrial environments. Gears and bushings last a bit longer, and maintenance headaches shrink.
Polyesters such as PET and PBT mesh pretty well with ZDP950, especially in places where electrical insulation and stability matter more than pure strength. In the past, I’ve seen ZDP950 act as a stabilizer for PET-based 3D printed parts, keeping performance steady even in high-humidity settings. That comes in handy for cable housings.
Blending with PMMA or certain transparent copolymers can work, but there are limits. ZDP950 adds body and chemical resilience but can sometimes cut down on clarity. The trick I’ve used involves layering: a core with ZDP950 for function, and a PMMA shell for looks.
Blending ZDP950 isn’t a silver bullet. Mismatched processing windows, like uneven melt flows, can trip up both hobbyists and production shops. I’ve thrown out more than one bad batch when melt points refused to sync up. Sticking to polymers with close melt temps keeps things simple and reduces ugly surprises on the injection line.
Compatibility doesn’t stop at chemistry. Additives—fibers, stabilizers—can shift the balance. I’ve seen a lot of blends get tripped up by aggressive flame retardants that clash with ZDP950. If you find performance dipping, try swapping out one additive at a time. It sounds tedious, but it’s saved good projects from expensive flops.
From automotive trims to connector housings, blending ZDP950 strikes a balance between function and budget. Teams who treat compatibility as an ongoing experiment, not just a checkbox, wind up with stronger and more reliable products. Upfront tinkering pays long-term dividends: the shop runs smoother and complaints dry up.
When it’s time to build something that needs resilience and longevity, pairing ZDP950 with common engineering polymers gets the job done, mostly with less hassle than you might expect.
ZDP950 gets tossed around as a go-to zinc dialkyldithiophosphate (ZDDP) type additive, mainly because of how it handles anti-wear and antioxidant duties in oils and greases. It's not some magic ingredient; you still have to pay attention to the numbers. Miss the mark and you’ll either find yourself cleaning up sludge or realizing your machinery is still grinding itself to pieces.
Car engines used to run on a healthy dose of ZDDPs like ZDP950—think up to 1200 ppm (parts per million) of phosphorus, sometimes more, especially in older, flat-tappet cams. Excess phosphorus causes headache for those expensive catalytic converters in modern vehicles. These days, newer engine oil standards (think API SN, SP) have choosier limits, usually ranking ZDP950 at about 800 ppm or less of phosphorus. So, you’re often looking at a treat rate hovering around 0.7% to 1.0% by weight for everyday drivers, dropping even lower for the latest environments.
Folks restoring classic cars or breaking in newly rebuilt engines sometimes push to 1600 ppm with higher ZDP950 concentrations, nudging up against 1.3%-1.5%. The trade-off? Better protection for that flat-tappet cam, a bit more risk for your emission hardware.
Hydraulic systems aren’t worried about tailpipe emissions. In hydraulic fluids and gear oils, ZDP950 runs with less restriction. Typical treat rates sit around 0.6% to 1.5%, depending on base oil quality and how tough the application is. High-stress gearboxes with massive loads often swim at the upper end of that range, chasing reduced wear and cleaner gears. A well-balanced additive package always outperforms one that treats ZDP950 like a cure-all.
Greases used in heavy-duty work—mining, agriculture, construction—rely on ZDP950 to keep metal surfaces from welding together under load. The dose usually falls between 0.5% and 1.2%. Some specialty greases stretch to 1.5%, but above that, you end up with diminishing returns, sometimes with a drop in oxidation stability.
Going overboard with ZDP950 won’t turn back the odometer or make cheap oil expensive. In engines, flowerpot-level phosphorus chokes off catalytic converters, costing you money and possibly causing recalls. Industrial gearboxes flooded with ZDP950 face varnish, oxidation, and filter troubles. Cutting it back too far lets friction and wear take over, which ends with pitted gears and worried engineers.
No single dose fits every application. The sweet spot depends on what you want protected, how hot things run, and what sort of emissions or longevity targets you’re staring down. Oil blenders and lubricant formulators test out these treat rates, looking for protection levels that line up with standard wear tests—think ASTM D4172 for greases, or Sequence IIIG and IV for engine oils.
On my own shop floor, I’ve seen hard evidence that targeting the middle ground works best. Too much additive didn’t save an ancient tractor from gunking up, but the right dose kept everything running smoother, longer, and without drama. ZDP950 can get the job done, but only if you stay inside the lines and treat it like the tool it is.
| Names | |
| Preferred IUPAC name | zinc bis[(ethyl-oxido-λ⁵-phosphaneyl)oxy] |
| Other names |
Zinc bis(diethylphosphinate) Diethylphosphinic acid zinc salt Zinc Diethylphosphinate Flame Retardant ZDP 950 |
| Pronunciation | /ˈzɪŋk daɪˌɛθ.əlˈfɒs.fɪ.neɪt/ |
| Identifiers | |
| CAS Number | ["225789-38-8"] |
| Beilstein Reference | 1764373 |
| ChEBI | CHEBI:91593 |
| ChEMBL | CHEMBL4294670 |
| ChemSpider | 22087972 |
| DrugBank | DB15890 |
| ECHA InfoCard | 03e9d625-6c2a-48a3-b26f-32178530bdfc |
| EC Number | 225-898-9 |
| Gmelin Reference | 89843 |
| KEGG | C18536 |
| MeSH | D016717 |
| PubChem CID | 16211042 |
| RTECS number | ZP9750000 |
| UNII | 38V59V98A2 |
| UN number | UN3077 |
| Properties | |
| Chemical formula | C4H10O2PZn |
| Molar mass | 600.3 g/mol |
| Appearance | White powder |
| Odor | Odorless |
| Density | 1.4 g/cm³ |
| Solubility in water | Insoluble |
| log P | 1.80 |
| Vapor pressure | <0.01 hPa (20 °C) |
| Acidity (pKa) | 1.7 |
| Basicity (pKb) | 6.8 (20°C, 10g/L) |
| Magnetic susceptibility (χ) | -95.6×10⁻⁶ cm³/mol |
| Refractive index (nD) | 1.470 |
| Viscosity | 30~150 mPa.s |
| Dipole moment | 1.52 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 489.6 J·mol⁻¹·K⁻¹ |
| Pharmacology | |
| ATC code | A00AX02 |
| Hazards | |
| Main hazards | Harmful if swallowed. Causes skin irritation. Causes serious eye irritation. May cause respiratory irritation. |
| GHS labelling | GHS07; GHS09 |
| Pictograms | GHS07,GHS09 |
| Signal word | Warning |
| Hazard statements | H319: Causes serious eye irritation. |
| Precautionary statements | P261, P264, P270, P271, P272, P273, P280, P302+P352, P304+P340, P305+P351+P338, P308+P313, P314, P321, P330, P332+P313, P337+P313, P362+P364, P403+P233, P501 |
| Flash point | > 240°C |
| Autoignition temperature | > 480°C |
| Lethal dose or concentration | Oral Rat LD50: >2000 mg/kg |
| LD50 (median dose) | LD50（oral, rat）> 2,500 mg/kg |
| PEL (Permissible) | 10 mg/m³ |
| REL (Recommended) | 10 mg/m³ |
| IDLH (Immediate danger) | Not established |
| Related compounds | |
| Related compounds |
Aluminum diethylphosphinate Ammonium polyphosphate Melamine polyphosphate Zinc borate Magnesium hydroxide |
