Tribasic Copper Sulfate TBCS · Cu₄(OH)₆SO₄ · CAS 1344-73-6
Copper sulfate that does not dissolve — which is the entire point. Twice the copper of the pentahydrate, and the low solubility that makes a copper safe to put on a leaf.
Chelora Chemicals is a tribasic copper sulfate supplier and sourcing partner serving crop protection formulators and feed mineral producers across the United States, with a batch COA, SDS and UN 3077 documentation on every consignment.
- CAS Number
- 1344-73-6
- Chemical name
- Basic copper sulfate
- Molecular formula
- Cu₄(OH)₆SO₄
- Copper as Cu
- ≈ 55.5% metallic
- Theoretical Cu
- 56.2%
- Appearance
- Green powder
- Water solubility
- Practically insoluble
- Transport
- UN 3077 · Class 9 · PG III
- HS Code
- 2833 25
Note: three CAS numbers circulate for this material — order by the EPA one. A US EPA-registered technical product declares the active as Basic Copper Sulfate, CAS 1344-73-6, at 98.7% with a metallic copper equivalent of 55.5%. You will also see 12068-81-4 and 1333-22-8 quoted for the same chemistry in supplier literature. The arithmetic cross-checks on the EPA figures: 55.5 ÷ 98.7 = 56.2%, exactly the theoretical copper in Cu₄(OH)₆SO₄. Confirm the CAS on the COA rather than on the product name.
From soluble sulfate to fixed copper
Tribasic copper sulfate is what you get when copper sulfate is taken most of the way to the hydroxide — and it is the insolubility that makes it useful.
Why it matters: soluble copper scorches foliage — the fixed coppers exist because insolubility is what lets copper sit on a leaf and release slowly
Why an insoluble copper sulfate exists
Tribasic copper sulfate is a green powder, Cu₄(OH)₆SO₄, carrying about 55.5% metallic copper. The name is slightly misleading: it behaves nothing like the blue copper sulfate pentahydrate it is made from. Where the pentahydrate dissolves freely and carries 25.45% copper, TBCS is practically insoluble and carries more than twice as much.
Both of those differences point the same way. A soluble copper scorches foliage, which is why Bordeaux needs lime to precipitate it. TBCS arrives already precipitated — a true fixed copper, sitting on the leaf and releasing copper ions slowly. It is also a feed trace mineral, where its stability in a premix is the attraction. It sits in the same family as copper hydroxide and copper oxychloride.
What the specification controls
- Copper as Cu, around 55.5% metallic. Against a theoretical 56.2% for the pure compound.
- CAS number on the COA. Three circulate for this chemistry; the EPA-registered one is 1344-73-6.
- Heavy metal limits. Published specifications set limits for cadmium, arsenic, lead, nickel and mercury.
- The soluble form for comparison: copper sulfate pentahydrate.
Handling character
TBCS is a Class 9 dangerous good on aquatic toxicity grounds. Full detail is in the Safety section below.
| Parameter | Typical value |
|---|---|
| Appearance | Green powder |
| Copper as Cu | ≈ 55.5% metallic, per agreed specification |
| Theoretical Cu for pure Cu₄(OH)₆SO₄ | 56.2% |
| pH, 1% aqueous dispersion | Typically 5.0–8.5 |
| Heavy metals | Cd, As, Pb, Ni, Hg per agreed limits |
| 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 | Green powder |
| Formula | Cu₄(OH)₆SO₄ |
| Copper as Cu, theoretical | 56.2% |
| Water solubility | Practically insoluble |
| pH, 1% dispersion | ≈ 5.0–8.5 |
| Mode of action | Multi-site contact; FRAC M1 |
| Versus pentahydrate | Insoluble; over twice the copper |
Physical constants compiled from public reference data and published technical specifications for basic copper sulfate, rounded for readability. Commercial material sits below the theoretical copper figure. Treat the table as orientation, not as a specification.
Where US industry uses TBCS
Fixed copper fungicide formulation and feed trace minerals.
Fungicide & bactericide formulation
A fixed copper for crop protection formulation, with an EPA-registered technical grade available in the US.
- ~55.5% metallic copper
- Grindability confirmed
- Registration sits with the registrant
Feed trace minerals
Used as a copper source in feed premixes, where its stability is the attraction over soluble copper sulfate.
- Feed-grade documentation on request
- Heavy metal limits specified
- Low dusting particle size
Resistance management programs
FRAC M1 multi-site activity, the same rotation benefit as the other fixed coppers.
- FRAC M1 on documentation
- Read the crop protection guide
- Program guidance on request
Copper density in formulation
At over twice the copper of the pentahydrate, TBCS delivers more copper per tonne formulated and shipped.
- 55.5% versus 25.45%
- Bulk and bagged supply
- Consistent assay lot to lot
Pigments & specialty uses
A green copper compound used where an insoluble copper source and a green color are both wanted.
- Shade matched to retained sample
- Low iron on request
- Small quantities available
Import & FIFRA coordination
End use decides the route: pesticidal use needs a Notice of Arrival and an EPA-registered product; feed and industrial use differ.
- End use confirmed before quoting
- UN 3077 documentation prepared
- Broker coordination on request
Delivered to US plants and ports
We ship tribasic copper sulfate 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
Tribasic copper sulfate 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 UN 3077 Class 9 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 or bulk bags |
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 tribasic copper sulfate
Chelora Chemicals is a tribasic copper sulfate supplier and sourcing partner, not a manufacturer. The first thing we settle on this line is the CAS number, because three circulate for the same chemistry and only one appears on the EPA-registered technical product.
We place your order with whichever qualified producer best matches your copper assay, heavy metal limits and your delivery window, and confirm the US import and FIFRA position before booking.
We keep a second qualified source on this line, so a single-plant disruption never becomes your formulation or premix schedule problem.
- CAS confirmed on the COA, not the product name. 1344-73-6 is the one on the EPA-registered technical; 12068-81-4 and 1333-22-8 also circulate for the same chemistry.
- Copper basis stated as metallic. Around 55.5% against a theoretical 56.2% — and the EPA label arithmetic cross-checks, so you can verify any quote.
- Heavy metal limits specified. Published specifications set limits for cadmium, arsenic, lead, nickel and mercury; for feed use these matter more than the copper figure.
- End use confirmed before quoting. Pesticidal, feed and industrial uses take different import routes.
- UN 3077 documentation prepared before booking. Class 9 on aquatic toxicity grounds; the paperwork is not optional.
- Batch traceability to the producing plant. Full chain of custody documentation on request.
Bagged or bulk bagged
25 kg bags, bulk bags or drums — all to UN 3077 marking and labeling requirements.
25 kg poly-lined bags
Moisture-barrier bags on stretch-wrapped pallets, UN-marked, the standard commercial unit.
500–1,000 kg bulk bags
Liner-fitted bulk bags for formulation and premix blending lines.
Fiber drums
Sealed fiber drums where extra moisture protection or extended storage is needed.
Small sealed units
Smaller sealed units for laboratory, pilot and formulation development work.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to, with dangerous goods documentation filed before booking.
Trial / sample quantities
Small packs dispatched for formulation and premix trials before a commercial order.
A Class 9 dangerous good on aquatic grounds
Tribasic copper sulfate is harmful by ingestion and irritating to eyes, and it is very toxic to aquatic life with long-lasting effects — which is what makes it a Class 9 dangerous good. A US EPA-registered technical product carries the signal word WARNING. The summary below is orientation only — the safety data sheet supplied with your specific batch is the authoritative document.
Classified hazards
H302Harmful if swallowed.H319Causes serious eye irritation.H410Very toxic to aquatic life with long lasting effects.
US registration, stated accurately. Basic copper sulfate is an EPA-recognized pesticide active ingredient, and an EPA-registered technical grade product exists — labeled "For Manufacturing Purposes Only" with a metallic copper equivalent of 55.5% and the signal word WARNING. That is a technical registration, not a licence to sell or apply a formulated product: under FIFRA the end product must itself be EPA-registered for US sale or use, that registration sits with the registrant and never with a raw material supplier, and an imported pesticide requires a Notice of Arrival, EPA Form 3540-1, filed with Customs. Feed use is a separate regulatory question and sits with your own nutrition and regulatory teams.
Storage
Store in sealed packaging in a dry, covered area away from food, seed and feedstuffs and away from strong acids. TBCS is practically insoluble and chemically stable, so it does not need the moisture control that copper sulfate pentahydrate requires or the temperature control that copper hydroxide requires. Bunded or contained storage is advised because of the aquatic hazard.
Handling
Handle with dust control, gloves and eye protection; the material is harmful if swallowed and irritates the eyes. Prevent any release to drains, watercourses or soil. Follow the exposure controls set out in the batch SDS.
Transport
Tribasic copper sulfate is classified as dangerous goods for transport on the basis of aquatic toxicity, normally shipped as UN 3077, Environmentally hazardous substance, solid, n.o.s., Class 9, Packing Group III. Marked and labeled packaging, a dangerous goods declaration and compliant documentation are required. We confirm and document the classification for your specific grade, 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
CAS, copper assay and basis, heavy metal limits, particle size and end use confirmed before order placement.
Producer batch testing
The producing plant tests each batch against the agreed specification before release.
Documentation review
COA, SDS, FIFRA position where pesticidal, and UN 3077 paperwork checked before booking.
Traceable dispatch
Each shipment is traceable to its producing batch, with full chain-of-custody records on request.
How TBCS is made and why it works
Tribasic copper sulfate is made by partially neutralizing a copper sulfate solution with alkali. Take the neutralization further and you arrive at copper hydroxide; stop at the right point and the product is Cu₄(OH)₆SO₄ — four coppers, six hydroxides and one sulfate, which is where "tribasic" comes from.
The commercial logic is the same one behind every fixed copper. Soluble copper scorches foliage: it is why Bordeaux needs lime to precipitate the copper before it goes on the crop. TBCS arrives already precipitated and practically insoluble, so it sits on the leaf surface and releases copper ions slowly as moisture and plant exudates act on it. It also carries over twice the copper of the pentahydrate — about 55.5% against 25.45% — so it delivers more copper per tonne formulated and shipped.
The naming is the one trap. Three CAS numbers circulate for this chemistry — 1344-73-6, 12068-81-4 and 1333-22-8 — and the US EPA-registered technical product uses the first. Its arithmetic is a useful check on any quote: 98.7% active declared at 55.5% metallic copper works out to 56.2%, exactly the theoretical copper in the pure compound.
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 | Basic copper sulfate |
|---|---|
| Made from | Copper sulfate partially neutralized |
| Copper content | ≈ 55.5% metallic; 56.2% theoretical |
| Key property | Practically insoluble — a fixed copper |
| Versus pentahydrate | Over twice the copper, and insoluble |
| Ordering trap | Three CAS numbers circulate |
The copper sulfate range and the fixed coppers
The soluble copper sulfate grades, the Bordeaux family and the other fixed coppers.
Tribasic copper sulfate, answered
What is tribasic copper sulfate?
How does it differ from copper sulfate pentahydrate?
Which CAS number is correct?
What copper content should I expect?
Is it used as a feed trace mineral?
Is it a fixed copper like copper hydroxide?
What heavy metal limits apply?
Is it dangerous goods to ship?
Can I sell or apply this in the United States?
Do you supply tribasic copper sulfate in the United States?
Get a quote on tribasic copper sulfate
Send us your required copper assay and basis, heavy metal limits, particle size, pack size and US delivery point — and tell us the end use, because pesticidal, feed and industrial routes differ. We will confirm the CAS on the COA before you commit.