Copper hydroxide

Copper hydroxide (CAS 20427-59-2), also known as cupric hydroxide, is an inorganic copper salt used industrially as a biocide, fungicide, and pH-regulating agent.

Where is Copper hydroxide used?

• Agriculture: active ingredient in crop protection formulations targeting fungal and bacterial diseases in fruits, vegetables, and cereals including downy mildew and fire blight
• Water treatment: controls algae and microbial growth in industrial cooling systems and municipal infrastructure
• Wood preservation and process chemical
• Precursor in the production of other copper compounds and specialty catalysts
• It releases copper ions through controlled reactivity.
• Metal surface treatment.
• Production of pigments for paper dyeing.
• Ceramics.

Formulation notes

• For pome fruits (pear, apple, quince, medlar, nashi) against cankers, apply 280-400 g/hl (2.8-4.0 kg/ha) in autumn-winter and pre-flowering treatments, with 7-21 day intervals and max 4 treatments per year.
• For grapevine against downy mildew, apply 200-270 g/hl (2.0-2.65 kg/ha) when disease-favorable conditions occur, with 7-14 day intervals and max 6 treatments per year.
• For olive against peacock spot, bacterial diseases, and sooty mold, apply 300-400 g/hl (3.0-4.0 kg/ha) when disease-favorable conditions occur, with 14-30 day intervals and max 4 treatments per year.
• For citrus (orange, grapefruit, lemon, lime, mandarin, etc.) against gummosis, apply 320-400 g/hl (3.2-4.0 kg/ha) when disease-favorable conditions occur, with 7-14 day intervals and max 4 treatments per year.

Typical specification

• Available in wettable powder (WP), water-dispersible granule (WG), suspension concentrate (SC), and dust (poudrage) formulations.
• Available as a 50% formulation equivalent to metallic copper.
• Flowability is tested by method MT172, CIPAC F, p.430.
• The acute toxicity estimate by inhalation is 0.47 mg/L (dusts/mists).

Regulatory status

• For use in plant protection, a purity of at least 573 g Cu/kg is required.
• Registered as an active substance in Türkiye.
• Covered by FAO specifications for plant protection products, edition 1998.
• Included as an active substance in plant protection products under EU Directive 2009/37/EC, with uses only as bactericide and fungicide authorized.

Storage, packaging and handling

• Stored in its original packaging under the conditions specified in the safety data sheet (SDS).

Frequently asked questions about Copper hydroxide

Can copper hydroxide products be used in organic farming?

Copper hydroxide products are usable in organic farming.

How should the total copper load be calculated when using copper hydroxide?

The total copper load must be calculated from all copper-based products used, regardless of formulation, and must remain within legal limits.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.