Disodium Octaborate DOT · Na₂B₈O₁₃·4H₂O · CAS 12280-03-4
The highly soluble borate behind US wood preservation — sold as DOT, and marketed under names including Polybor and Tim-bor. Far more soluble than borax, which is what makes it work as a diffusible treatment.
Chelora Chemicals is a disodium octaborate supplier and sourcing partner serving wood treaters, insulation manufacturers and agricultural formulators across the United States, with a batch COA and SDS on every consignment.
- CAS Number
- 12280-03-4
- EC Number
- 234-541-0
- Chemical name
- Disodium octaborate
- Molecular formula
- Na₂B₈O₁₃·4H₂O
- Molecular weight
- 412.52 g/mol
- B₂O₃ content
- 66.2–69.0%
- Forms supplied
- Powder · granular
- Transport
- Not DG regulated
- HS Code
- 2840 20
Note: hydrate naming differs across catalogs. CAS 12280-03-4 is registered as the tetrahydrate, Na₂B₈O₁₃·4H₂O, and that is what Polybor and Tim-bor are. The same CAS is sometimes listed as a pentahydrate. Confirm the hydrate state and B₂O₃ assay against the batch COA rather than the product name.
From borate ore to soluble treatment
Disodium octaborate is made by reacting borax with boric acid to lift the boron content and the solubility well above either starting material.
Why it matters: borax dissolves to roughly 5% at room temperature, DOT to around 9.5% — and far higher warm — which is what makes a diffusible wood treatment practical
What disodium octaborate is used for
Disodium octaborate is a white, odorless borate powder or granule carrying 66 to 69% B₂O₃ — a higher boron loading than borax, and a much higher solubility. It is made by fusing borax with boric acid, and the result dissolves readily enough to be sprayed, injected or foamed into timber.
That solubility is the whole commercial point. In wood preservation it diffuses into wet or green timber and stays there, controlling fungal decay and wood-boring insects including termites. In cellulose insulation it serves as both flame retardant and pest deterrent. In agriculture it delivers boron as a micronutrient where deficiency limits yield.
Forms and grades we quote against
- Powder. Dissolves fastest, the standard form for spray and dip treatment solutions and for dry blending.
- Granular. Dust-free and free-flowing, preferred for bulk handling, bagging lines and broadcast agricultural use.
- Technical grade, 66–69% B₂O₃. The standard commercial assay for industrial and wood-treatment service.
- Related inorganics from the same desk: sodium silicofluoride and calcium chloride.
Handling character
Disodium octaborate is a low acute-hazard solid, but borates carry reproductive-toxicity classifications in several jurisdictions. Full detail is in the Safety section below.
| Parameter | Typical value |
|---|---|
| Appearance | White powder or free-flowing granules |
| B₂O₃ content | 66.2–69.0% |
| Na₂O content | ≈ 17–19% |
| Moisture (loss on drying) | Per grade specification |
| Water insolubles | 0.1% max |
| Particle size | Per agreed sieve specification |
Important: the figures above are indicative of commercial material and are offered for planning only. The batch certificate of analysis is the governing document.
| Property | Value |
|---|---|
| Physical state | White odorless crystalline solid |
| Molecular weight | 412.52 g/mol |
| Water solubility | ≈ 9.5 g/100 mL at 20 °C |
| Solubility vs borax | Roughly twice that of borax |
| pH (3% solution) | ≈ 8.0–8.5 |
| Bulk density | ≈ 0.8–1.0 g/cm³ by form |
| Thermal behavior | Loses water of hydration on heating |
Physical constants compiled from public reference data for CAS 12280-03-4 and rounded for readability. Solubility rises sharply with temperature. Treat the table as orientation, not as a specification.
Where US industry puts DOT to work
Wood preservation, insulation, agriculture and industrial fluids — all resting on the same solubility.
Wood preservation & remedial treatment
Diffuses into wet or green timber to control fungal decay and wood-boring insects including termites. The basis of borate wood treatment in the US.
- Powder for solution make-up
- Documented batch traceability
- EPA registration is the formulator’s responsibility
Cellulose insulation
Serves as flame retardant and pest deterrent in blown and batt cellulose insulation, blended dry with the fiber.
- Granular for dry blending
- Consistent assay lot to lot
- Bulk and bagged supply
Boron micronutrient fertilizer
Delivers boron where soil deficiency limits yield, applied as a foliar spray or in blended fertilizer.
- High solubility suits foliar use
- Agricultural grade available
- Read the agrochemical guide
Industrial fluids & corrosion inhibition
Buffers and inhibits corrosion in metalworking fluids, antifreeze and water-treatment formulations.
- Technical grade to your assay
- Powder or granular
- Technical desk review on request
Glass, ceramics & frits
A boron source in specialty glass, glaze and frit batches where a soluble borate is preferred to borax.
- Low insolubles specification
- Bulk bag supply
- Retained sample held against the lot
Contract & scheduled supply
Insulation and wood-treatment demand is seasonal, so contracted tonnage and call-off scheduling matter on this line.
- Annual contracts with scheduled call-off
- Price held across the contract period
- Second source held in reserve
Delivered to US plants and ports
We ship disodium octaborate to nominated delivery points across the United States. The regions below are destinations we serve — Chelora Chemicals is a sourcing and supply partner, not a US manufacturer, and does not hold US stock.
Gulf Coast
The largest US chemical cluster, and the usual entry point for bulk consignments.
- Houston & Galveston, TX
- New Orleans & Baton Rouge, LA
- Mobile, AL
Northeast
Container and bulk delivery into the mid-Atlantic and New England manufacturing belt.
- Newark & Elizabeth, NJ
- Philadelphia, PA
- Boston, MA
Southeast
Port-side delivery for the Carolinas, Georgia and Florida processing plants.
- Savannah, GA
- Charleston, SC
- Jacksonville, FL & Norfolk, VA
Midwest & Great Lakes
Inland rail and truck forwarding from the nearest coastal port to the industrial Midwest.
- Chicago, IL
- Detroit, MI
- Cleveland & Columbus, OH
West Coast
Pacific routing for West Coast processors and formulators.
- Los Angeles & Long Beach, CA
- Oakland, CA
- Seattle & Tacoma, WA
Southwest & Mountain
Inland delivery to interior states, forwarded from the Gulf or Pacific gateway.
- Dallas–Fort Worth, TX
- Phoenix, AZ
- Denver, CO
Importing into the United States
Disodium octaborate is a TSCA-regulated chemical substance. Under TSCA section 13 the importer of record, or its authorized agent, must certify to US Customs and Border Protection that each shipment either complies with TSCA or is not subject to it. We confirm the substance's TSCA Inventory status and agree in writing who files that certification before the first consignment moves.
Which party carries that duty follows the Incoterm. On FOB, CFR or CIF terms it is usually the US buyer; on DDP terms it can be the seller or its agent. Safety data sheets and labels are supplied to OSHA's updated Hazard Communication Standard, and the non-hazardous transport documentation is prepared before booking.
| Item | How it works |
|---|---|
| Delivery points | Any nominated US plant, terminal or port of discharge |
| Incoterms quoted | FOB · CFR · CIF · DDP |
| Importer of record | Agreed in writing before the first shipment |
| TSCA certification | Section 13 positive certification filed at entry |
| Documentation | Batch COA, SDS, packing list, certificate of origin |
| Pack formats | 25 kg bags, bulk bags or bulk |
Note: regional coverage describes where we deliver, not where we hold inventory. Lead time depends on producer scheduling and ocean transit to your nominated US port — we confirm both in the quotation.
How we supply disodium octaborate
Chelora Chemicals is a disodium octaborate supplier and sourcing partner, not a manufacturer. On a borate the variables that bite are B₂O₃ assay, particle size and moisture — and the naming confusion between hydrate forms, which we settle before quoting rather than after.
We place your order with whichever qualified producer best matches your required grade, your price point and your delivery window, and confirm US import requirements before booking.
We keep a second qualified source on this line, so a single-plant disruption never becomes your production problem.
- B₂O₃ assay confirmed before we quote. The 66–69% band is wide enough to change your dose rate, so we hold the figure you specify.
- Hydrate state settled in writing. Catalogs disagree on whether this material is the tetrahydrate or pentahydrate — we confirm what the COA actually says before the order is placed.
- Particle size agreed up front. A dissolution tank and a dry-blending line want different things; powder and granular are not interchangeable.
- TSCA status and import certification settled first. We confirm Inventory status and agree who files the section 13 certification before the first shipment.
- Pesticide registration stays with you. Where the end use is a registered wood preservative or insecticide, EPA registration is the formulator’s responsibility, not ours — we supply the raw material and the documentation.
- Batch traceability to the producing plant. Full chain of custody documentation on request.
Bagged, bulk-bagged or delivered in bulk
25 kg bags, bulk bags or bulk truck — tell us your handling arrangement and we will quote to it.
25 kg / 50 lb poly bags
Moisture-barrier bags on stretch-wrapped pallets, the standard unit for treatment plants.
1,000 kg bulk bags
Liner-fitted bulk bags for insulation lines and high-volume blending operations.
Bulk truck delivery
Bulk delivery to silo for continuous insulation and agricultural blending operations.
Small sealed units
Sealed units for laboratory, trial and small-batch formulation work.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to, with documentation filed before booking.
Trial / sample quantities
Small packs dispatched for solubility and formulation trials before a commercial order.
Low acute hazard, but check the borate classification
Disodium octaborate has low acute toxicity and is not classed as dangerous goods for transport. The significant question is the reproductive-toxicity classification that several jurisdictions apply to borates as a group. The summary below is orientation only — the safety data sheet supplied with your specific batch is the authoritative document.
Classified hazards
H360FDMay damage fertility. May damage the unborn child.H319Causes serious eye irritation.
Classification differs by jurisdiction. The European Union classifies disodium octaborate and several related borates as Repr. 1B, carrying H360FD. Some US safety data sheets classify more narrowly, on eye and skin irritation alone. Because OSHA Hazard Communication follows the classification the supplier assigns, the SDS issued with your batch governs — and your occupational-health program should be built on it rather than on a generic borate profile.
Storage
Store in sealed, moisture-barrier packaging in a dry, covered area off the floor. The material cakes if it takes up moisture, and dissolves readily once wet. Keep away from strong acids and from incompatible oxidizers.
Handling
Handle with dust control and eye protection; the dust irritates eyes. Wear gloves where contact is prolonged. Where the reproductive-toxicity classification applies, follow the exposure controls set out in the batch SDS and your own occupational-health program.
Transport
Disodium octaborate is normally not regulated as dangerous goods for road, rail or sea transport, so no UN number applies to the standard grades. We confirm and document the position for your specific shipment, packaging and destination before booking.
Every batch, documented
We verify documentation before dispatch so there are no surprises at your incoming-goods bench.
Specification agreed
B₂O₃ assay, hydrate state, particle size, moisture and insolubles confirmed against your requirement before order placement.
Producer batch testing
The producing plant tests each batch against the agreed specification before release.
Documentation review
COA, SDS and TSCA certification data checked by our desk, and pack moisture barrier confirmed, before the shipment is booked.
Traceable dispatch
Each shipment is traceable to its producing batch, with full chain-of-custody records on request.
How disodium octaborate is made
Disodium octaborate is made by reacting borax with boric acid in a controlled ratio and then drying and sizing the product. Both starting materials come from refined borate ore — tincal, colemanite or ulexite — mined principally in Turkey and in California.
The point of the reaction is solubility. Borax dissolves to roughly 5% at room temperature, which is not enough to carry a useful boron dose into timber in a single application. Disodium octaborate reaches around 9.5% cold and far higher warm, and it carries more B₂O₃ per unit weight. That is why borate wood treatment is built on this material rather than on borax.
Hydrate naming is where catalogs diverge. CAS 12280-03-4 is registered as the tetrahydrate, and that is what the main branded products are. Some suppliers list the same CAS as a pentahydrate. We confirm what the COA states before quoting.
We do not publish operating process parameters here; this is background only. Full technical documentation accompanies every shipment, and any process-specific detail you need is best confirmed directly with our technical desk.
| Chemical family | Soluble sodium borate |
|---|---|
| Made from | Borax reacted with boric acid |
| Key property | Roughly twice the solubility of borax |
| Boron loading | 66–69% B₂O₃ |
| Branded equivalents | Polybor, Tim-bor and similar DOT products |
| Downstream | Wood preservation, insulation, boron micronutrient |
The rest of the inorganic range
Other salts, alkalis and acids supplied from the same desk.
Disodium octaborate, answered
What is disodium octaborate used for?
Is it the tetrahydrate or the pentahydrate?
Why use disodium octaborate instead of borax?
What is the difference between powder and granular?
Is disodium octaborate hazardous?
Do you supply EPA-registered wood preservative?
What B2O3 content do you supply?
What packing do you offer?
Do you supply disodium octaborate in the United States?
Do you manufacture this yourself?
Get a quote on disodium octaborate
Send us your required B₂O₃ assay, form, particle size, pack size and US delivery point. We will come back with a firm quote, lead time and full documentation — and will confirm the hydrate state on the COA before you commit.