Copper Hydroxide Technical Cu(OH)₂ · CAS 20427-59-2
More copper per tonne than copper oxychloride, and far less heat-tolerant — 65% copper against 59%, but it decomposes above roughly 80 °C and tells you it has by turning dark.
Chelora Chemicals is a copper hydroxide technical supplier and sourcing partner serving formulators across the United States, with a batch COA, SDS and UN 3077 documentation on every consignment.
- CAS Number
- 20427-59-2
- Chemical name
- Copper(II) hydroxide
- Molecular formula
- Cu(OH)₂
- Molecular weight
- 97.56 g/mol
- Copper as Cu (theoretical)
- 65.1%
- Commercial assay
- Per agreed specification
- Appearance
- Blue to greenish-blue powder
- Transport
- UN 3077 · Class 9 · PG III
- HS Code
- 2825 50
Note: two US labels, two different conversion bases. Kocide 3000 declares 46.1% copper hydroxide as 30% metallic copper — a ratio of 65.1%, the exact stoichiometric figure for pure Cu(OH)₂. Nu-Cop XLR declares 17.06% as 10% metallic copper — a ratio of 58.6%, implying a technical input around 90% pure. Both are registered US products. So the compound percentage alone does not tell you the copper; confirm the assay basis on the COA rather than inferring it.
From copper salt to stabilized hydroxide
Copper hydroxide is precipitated from a soluble copper salt with alkali — and then has to be stabilized, because the raw precipitate will not keep.
Why it matters: the raw precipitate decomposes to black CuO on standing — commercial material is stabilized, and that stabilization is the producer’s real know-how
What copper hydroxide technical is used for
Copper hydroxide technical is a blue to greenish-blue powder, Cu(OH)₂, and it is a formulation feedstock rather than a finished product. Its commercial appeal over copper oxychloride is simple arithmetic: pure Cu(OH)₂ is 65.1% copper by weight against 59.5% for copper oxychloride, so it delivers more copper per tonne shipped and per tonne formulated.
The catch is stability. Copper hydroxide decomposes to copper(II) oxide on heating — the literature puts the threshold around 80 to 100 °C — and the material darkens toward black as it does. Commercial technical grade is therefore stabilized, and that stabilization is the producer’s genuine know-how. It is also why color is a quality signal on this compound in a way it is not on most inorganics.
What the specification actually controls
- Copper as Cu. Theoretical maximum 65.1%; commercial technical sits below it and is agreed per order.
- Stabilization. Resistance to decomposition in storage — the parameter that separates producers.
- Color. A darkened lot has begun converting to copper oxide; shade is a condition signal here, not a cosmetic one.
- The alternative chemistry: copper oxychloride technical, lower copper but far more heat-tolerant.
Handling character
Copper hydroxide is a Class 9 dangerous good and is heat-sensitive. Full detail is in the Safety section below.
| Parameter | Typical value |
|---|---|
| Appearance | Blue to greenish-blue powder |
| Copper as Cu | Per agreed specification |
| Theoretical Cu for pure Cu(OH)₂ | 65.1% |
| Stabilization | Per producer specification |
| Moisture (loss on drying) | Per grade specification |
| 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 | Blue to greenish-blue solid |
| Molecular weight | 97.56 g/mol |
| Density | 3.37 g/cm³ |
| Decomposition | To CuO above ≈ 80–100 °C |
| Water solubility | Negligible |
| Visual decomposition sign | Darkens toward black |
| Copper content, theoretical | 65.1% |
Physical constants compiled from public reference data for CAS 20427-59-2 and rounded for readability. Published sources give the decomposition threshold variously as about 80 °C and about 100 °C; commercial material is stabilized and behaves better than the pure compound. Treat the table as orientation, not as a specification.
Where US industry uses copper hydroxide
Fungicide formulation above all, plus pigments, catalysis and specialty chemistry.
Fungicide formulation
The dominant use. Milled and blended into WP, dry flowable and suspension concentrate copper fungicides.
- Stabilized grade
- Grindability confirmed per lot
- See the 50% WP page
Products for organic production
Some registered copper hydroxide products are labeled for organic production — a route copper oxychloride largely lacks in the US.
- Organic status sits with the registrant
- Documented batch traceability
- Certifier approval is yours to obtain
Pigments & colorants
A blue to greenish-blue colorant where the shade and the copper content are both wanted.
- Shade matched to retained sample
- Low iron on request
- Stabilization specified
Catalysis & specialty chemistry
A copper source in catalysis and in preparations such as Schweizer’s reagent for dissolving cellulose.
- Particle size to specification
- Consistent assay lot to lot
- Technical desk review on request
Import & compliance coordination
End use decides the import route: pesticidal use triggers FIFRA and a Notice of Arrival, pigment or catalyst use does not.
- End use confirmed before quoting
- UN 3077 documentation prepared
- Broker coordination on request
Contract & scheduled supply
Formulation plants run seasonal campaigns against a spray calendar, so contracted tonnage with call-off scheduling matters.
- Annual contracts with call-off
- Price held across the contract
- Second source held in reserve
Delivered to US plants and ports
We ship copper hydroxide technical 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
Copper hydroxide technical 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 copper hydroxide technical
Chelora Chemicals is a copper hydroxide supplier and sourcing partner, not a manufacturer. On this compound the variable that separates producers is not assay — it is stabilization, because an unstabilized or poorly stabilized lot will darken in your warehouse and lose copper to oxide.
We place your order with whichever qualified producer best matches your specification, your price point 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 schedule problem.
- Copper assay basis confirmed on the COA, not inferred. US registered products declare on different bases — one uses the stoichiometric 65.1%, another an effective 58.6% — so the compound percentage alone does not tell you the copper.
- Stabilization specified. The parameter that decides whether the lot survives your warehouse; we hold it on the order.
- Color recorded at dispatch. Darkening is the visible signal of conversion to copper oxide, so the shade at loading is documented.
- Cool storage planned into the route. Summer freight through the Gulf or Southwest is a real decomposition risk on this compound, unlike on copper oxychloride.
- UN 3077 documentation prepared before booking. Class 9 on aquatic toxicity grounds; the paperwork is not optional.
- FIFRA position settled honestly. We confirm whether your end use makes this a pesticide import, and we do not hold or lend registrations.
Bagged or bulk bagged
25 kg bags, bulk bags or fiber 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 unit for formulation plants.
500–1,000 kg bulk bags
Liner-fitted bulk bags for high-volume formulation lines.
Fiber or steel drums
Sealed 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, grindability and stability trials before a commercial order.
A Class 9 dangerous good — and heat-sensitive
Copper hydroxide is moderately hazardous by ingestion and causes eye irritation, but the classification that governs its logistics is aquatic toxicity — it is very toxic to aquatic life with long-lasting effects, which is what makes it a Class 9 dangerous good. The summary below is orientation only — the safety data sheet supplied with your specific batch is the authoritative document.
Classified hazards
H302Harmful if swallowed.H315Causes skin irritation.H319Causes serious eye irritation.H410Very toxic to aquatic life with long lasting effects.
Copper hydroxide is different from copper oxychloride on US registration, and it matters. Copper hydroxide is among the most widely EPA-registered copper fungicide actives in the United States, with a large family of registered products in current commercial use, and some of them are labeled for use in organic production. That does not change the rule: under FIFRA a pesticide 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. Organic status is product-specific and sits with the registrant and the certifier, not with us.
Storage
Store in sealed original packaging in a cool, dry, well-ventilated area, away from food, seed and feedstuffs and away from acids. Temperature is the controlling variable on this compound: copper hydroxide decomposes to copper(II) oxide on heating and darkens visibly as it does. Do not store in direct sun, against hot walls or in unventilated containers in summer. Bunded or contained storage is advised because of the aquatic hazard.
Handling
Handle with dust control, impervious gloves and eye protection; the material is harmful if swallowed and irritates the eyes, and repeated skin contact may sensitize some individuals. Prevent any release to drains, watercourses or soil. Follow the exposure controls set out in the batch SDS.
Transport
Copper hydroxide and its formulations are 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 IMDG or DOT-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
Copper content basis, crystal form, shade, particle size and moisture 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, TSCA or FIFRA position and UN 3077 dangerous goods paperwork checked by our desk before the shipment is booked.
Traceable dispatch
Each shipment is traceable to its producing batch, with full chain-of-custody records on request.
How copper hydroxide is made
Copper hydroxide is precipitated from a soluble copper salt with alkali — typically a copper chloride or sulfate solution treated with caustic soda. The chemistry is trivial. The difficulty is everything that happens next.
The raw precipitate is unstable. Left alone it dehydrates toward copper(II) oxide, Cu(OH)₂ → CuO + H₂O, and the material darkens toward black as it goes. Published sources put the threshold around 80 to 100 °C, but the conversion is also driven by time, moisture and particle size, not temperature alone. Commercial technical grade is therefore stabilized — and the stabilization method is the producer’s real know-how and the thing that distinguishes one supplier from another.
That instability is also why color is a condition signal on this compound. Reference works note that stabilized commercial forms are pale greenish-blue rather than the pure compound’s blue, and that some are mixtures of hydroxide and carbonate. A lot that arrives noticeably dark has begun converting, and no assay certificate issued at the plant will tell you what happened in transit.
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 | Copper(II) hydroxide |
|---|---|
| Made from | Copper salt precipitated with alkali |
| Copper content | 65.1% theoretical — highest of the fixed coppers |
| Weakness | Decomposes to CuO on heating |
| Visual warning sign | Darkening toward black |
| Commercial form | Stabilized; pale greenish-blue |
The copper range and related inorganics
The other copper grades and the salts and acids supplied from the same desk.
Copper hydroxide technical, answered
What is copper hydroxide technical used for?
Why choose copper hydroxide over copper oxychloride?
Why does copper hydroxide darken?
What is stabilized copper hydroxide?
What copper content does technical grade carry?
How should it be stored?
Is copper hydroxide dangerous goods?
Can I import this into the United States?
Do you supply copper hydroxide in the United States?
Do you manufacture this yourself?
Get a quote on copper hydroxide technical
Send us your required copper assay and basis, stabilization requirement, particle size, pack size and US delivery point — and tell us the end use, because it decides the import route. We will confirm the assay basis on the COA before you commit.