Copper Sulfate, Cupric Sulfate, Copper Sulfate Pentahydrate, Cupric Sulfate Pentahydrate, Blue Vitriol, Blue Stone, 7758-98-7

Copper Sulfate, Cupric Sulfate, Copper Sulfate Pentahydrate, Cupric Sulfate Pentahydrate, Blue Vitriol, Blue Stone, 7758-98-7

COPPER SULFATE (CuSO₄, CuSO₄·5H₂O)

1. Chemical Identity and Material Classification

• Chemical Name: Copper(II) Sulfate, Cupric Sulfate

• Synonyms: Copper Sulfate Pentahydrate, Blue Vitriol, Bluestone, Blue Stone, Copper(II) Sulfate, Cupric Sulfate Pentahydrate, Blue Copper, Chalcanthite (pentahydrate mineral)

• CAS Numbers:

  • Anhydrous Copper Sulfate: 7758-98-7

  • Copper Sulfate Pentahydrate (5H₂O): 7758-99-8

  • Copper Sulfate Monohydrate (1H₂O): 10257-55-9 (less common)

• EC Number (EINECS): 231-847-6 (anhydrous and pentahydrate share same EC number)

• Molecular Formula: CuSO₄ (anhydrous), CuSO₄·5H₂O (pentahydrate)

• Molecular Weight: 159.61 g/mol (anhydrous), 249.69 g/mol (pentahydrate)

• E Number: E519 (copper sulfate – restricted, not widely approved as food additive)

• Chemical Class: Inorganic salt, transition metal sulfate, copper salt

• HS Code: 2833.25

• UN Number: 3077 (Environmentally hazardous substance, solid, n.o.s. – for pentahydrate)

2. Physical Properties

2.1 General Physical Properties

2.2 Hydration Forms and Color Change

Color change (Dehydration): Blue pentahydrate → 110°C → white/gray anhydrous form. This characteristic change is used for water detection.

2.3 Solubility Properties

Important Note: Copper sulfate has very high solubility in water (~32 g/100 mL at 20°C). This makes it one of the most soluble copper salts. The solution is blue due to the hydrated Cu²⁺ ion.

2.4 Particle Characterization

2.5 Hygroscopicity and Stability

3. Chemical Properties

3.1 Molecular Structure

• Structure (anhydrous): Cu²⁺ [SO₄]²⁻

• Structure (pentahydrate): [Cu(H₂O)₄]²⁺ SO₄²⁻·H₂O (four water molecules coordinated to copper, one water molecule is free crystal water)

• Copper content (pentahydrate): 25.5% Cu (by weight)

• Copper content (anhydrous): 39.8% Cu (by weight)

• Sulfate content (pentahydrate): 38.4% SO₄ (by weight)

• Sulfate content (anhydrous): 60.2% SO₄ (by weight)

3.2 Thermal Properties (Dehydration and Decomposition)

Important Note: When heated, pentahydrate becomes completely anhydrous (white/gray) at approximately 200°C. Upon contact with water, the anhydrous form hydrates exothermically and turns blue – a characteristic property used for water determination.

3.3 Chemical Reactivity

3.4 Electrochemical Properties

3.5 Aqueous Solution Properties (Color and Complexes)

4. Commercial Grades and Specifications

5. Quality Specifications (Agricultural/Technical Grade – Pentahydrate)

6. Production Methods

6.1 Dissolution of Copper Metal in Sulfuric Acid (Most Common Method)

• Reaction: Cu + 2 H₂SO₄ (conc.) → CuSO₄ + SO₂ + 2 H₂O (hot, concentrated H₂SO₄)

• Alternate reaction (dilute acid + oxygen): 2 Cu + 2 H₂SO₄ + O₂ → 2 CuSO₄ + 2 H₂O

• Process:

  1. Copper metal scrap or copper ore is used.

  2. Dissolved in sulfuric acid (with heating).

  3. Pentahydrate form is obtained by crystallization.

  4. Filtered, washed, dried.

• Yield: 90–95%

• Purity: 98–99%

6.2 Dissolution of Copper Oxide or Hydroxide in Sulfuric Acid

• Reaction: CuO + H₂SO₄ → CuSO₄ + H₂O

• Reaction: Cu(OH)₂ + H₂SO₄ → CuSO₄ + 2 H₂O

• Process:

  1. Copper oxide or hydroxide is used.

  2. Dissolved in dilute sulfuric acid.

  3. Pentahydrate form is obtained by crystallization.

• Advantage: No SO₂ gas evolution; cleaner product.

• Purity: ≥99%

6.3 Roasting and Leaching of Sulfide Ores

• Reaction: 2 CuS + 3 O₂ → 2 CuO + 2 SO₂; CuO + H₂SO₄ → CuSO₄ + H₂O

• Process:

  1. Copper sulfide ores (e.g., chalcopyrite CuFeS₂) are roasted.

  2. Formed copper oxide is leached with sulfuric acid.

  3. Pentahydrate is obtained by crystallization.

• Use: As a mining by-product.

6.4 Electrolytic Method (High Purity)

• Process: Recovery from anode slime in electrolytic copper refining.

• Purity: ≥99.9%

7. Mechanism of Action (Functional Mechanisms)

7.1 Fungicide Mechanism (Agriculture – Largest Application ~75%)

• Slow release of copper ions (Cu²⁺): When copper sulfate contacts water, it slowly releases Cu²⁺ ions.

• Entry into fungal cell: Cu²⁺ ions penetrate the fungal cell wall.

• Intracellular effects:

  • Binds to thiol (-SH) groups in enzymes, inactivating them.

  • Disrupts the respiratory chain (cytochrome c oxidase inhibition).

  • Disrupts cell membrane integrity.

  • Generates reactive oxygen species (ROS) → oxidative stress.

• Result: Fungal spores do not germinate; mycelium does not grow. Contact fungicide (not systemic).

• Diseases controlled:

  • Downy mildew in grapes (Plasmopara viticola)

  • Late blight in tomatoes and potatoes (Phytophthora infestans)

  • Leaf spot in fruit trees

  • Fungal diseases in ornamental plants

  • Apple and pear scab

7.2 Herbicide / Algaecide Mechanism (Water Treatment, Ponds, Pools)

• Toxicity to algal cells: Cu²⁺ ions inhibit photosynthesis in algae (chloroplast damage).

• Cell membrane damage: Cu²⁺ peroxidizes lipids in the cell membrane.

• Result: Algal cells die; water becomes clear.

• Application areas:

  • Swimming pools (prevention of algal blooms)

  • Ponds and irrigation canals (algae control)

  • Roofs and walls (removal of green algae / lichen)

7.3 Animal Feed Additive (Growth Promoter / Copper Supplement)

• Trace element (copper) source: Copper is a cofactor for many enzymes (cytochrome c oxidase, superoxide dismutase, tyrosinase).

• Growth-promoting effect (poultry, swine):

  • Antibacterial effect (modulation of intestinal flora)

  • Improves feed conversion ratio (more meat with less feed)

  • Accelerates growth (5–10% increase)

• Copper deficiency treatment: Anemia, bone abnormalities, nervous system disorders, depigmentation of hair/feathers.

• Dosage (animal feed): 10–200 mg Cu/kg feed (depending on species; ~150 ppm for poultry)

7.4 Antiseptic / Disinfectant Mechanism

• Toxic effect on microorganisms: Cu²⁺ ions damage bacterial cell walls and enzymes.

• Protein denaturation: Cu²⁺ binds to thiol (-SH) and amino (-NH₂) groups in proteins.

• Applications:

  • Animal foot baths (foot rot – Fusobacterium necrophorum)

  • Wound treatment (topical antiseptic – historical use, limited today)

  • Water treatment (bactericidal effect)

7.5 Metal Plating / Copper Plating Mechanism

• Reaction (cementation / displacement): CuSO₄ + Fe → FeSO₄ + Cu (metallic copper deposits on surface)

• Electrolytic copper plating: Copper metal plating from CuSO₄ solution via electrolysis (PCB, decorative coatings).

7.6 Wine Production Impurity Removal

• Hydrogen sulfide (H₂S) removal: H₂S + CuSO₄ → CuS (black precipitate) + H₂SO₄

• Result: Sulfurous odor (rotten egg smell) in wine is eliminated; wine taste and quality improve.

8. Applications

8.1 Agriculture – Largest Application (~75%)

8.2 Animal Husbandry and Veterinary Medicine

8.3 Industry and Mining

8.4 Water Treatment and Swimming Pools

8.5 Construction and Building

8.6 Cosmetics and Personal Care

8.7 Pharmaceutical and Medical

8.8 Laboratory and Analytical Chemistry

8.9 Wine and Food Industry

9. Toxicology and Safety

9.1 Acute Toxicity

9.2 Chronic Toxicity and Special Concerns

9.3 GHS Classification

Signal word: DANGER

9.4 NFPA Rating

10. Environmental Impact and Toxicity

Important Environmental Warning:
Copper sulfate is very toxic to aquatic organisms. Even at very low concentrations (0.01 mg Cu/L), it has lethal effects on fish, algae, and invertebrates. It must not be discharged into surface waters, ponds, lakes, rivers, or sewers. Strict compliance with environmental regulations (Turkish Environmental Law, EU REACH/CLP, US EPA) is required.

11. Safety Precautions and Personal Protective Equipment (PPE)

Hazards:

• Toxic if swallowed. Copper poisoning symptoms: nausea, vomiting (may be blue/green), abdominal pain, diarrhea, headache.

• Harmful if inhaled (dust) – respiratory tract irritation.

• Causes skin irritation and serious eye damage.

• Very toxic to the aquatic environment. Avoid release to the environment.

• Not flammable.

• Reacts with strong reducing agents or metals (iron, zinc, aluminum). Copper metal precipitates.

PPE (mandatory – for dust or solution form):

• Respiratory protection: P2 or P3 filter mask (to prevent dust inhalation). Adequate ventilation for spray or solution applications.

• Eye protection: Chemical splash goggles (EN 166) or full face shield.

• Gloves: Nitrile or neoprene gloves (≥0.4 mm thickness). Natural rubber (latex) is not suitable.

• Protective clothing: Chemical-resistant apron or coverall (Tyvek, PVC).

• Footwear: Closed-toe, chemical-resistant boots.

Engineering controls:

• Local exhaust ventilation (LEV) with dust collection.

• Eyewash stations and safety showers.

• Spill containment equipment (neutralizers, absorbent materials – but do not wash with water – risk of environmental release).

• Prevent dust generation (closed systems, wet processing).

Storage conditions:

Incompatibilities (DO NOT MIX WITH):

• Metals (iron, zinc, aluminum, magnesium) → copper metal precipitates, heat evolves.

• Sulfides (Na₂S, H₂S) → forms CuS precipitate (not toxic) but heat evolves.

• Acetylene → forms copper acetylide (explosive).

• Strong reducing agents (hydrazine, sodium borohydride) → violent reaction, copper metal precipitation.

Firefighting:

• Non-flammable. Use extinguishing media appropriate for surrounding fire: water spray, dry chemical powder, CO₂, foam.

• In case of fire, toxic copper fumes (CuO) and sulfur oxides (SO₂, SO₃) may be released. Use SCBA.

First aid:

• Inhalation: Move to fresh air. Administer oxygen if breathing difficulty. Seek immediate medical attention.

• Skin contact: Remove contaminated clothing. Wash with plenty of water and soap for at least 15 minutes. Seek medical attention if irritation persists.

• Eye contact: Rinse with water for at least 15 minutes, lifting eyelids. Seek immediate medical attention.

• Ingestion: Rinse mouth. Do NOT induce vomiting. Drink water or milk (200–300 mL). Seek immediate medical attention. Never give anything by mouth to an unconscious person.

• Emergency information: Copper poisoning symptoms: nausea, vomiting (may be blue/green), abdominal pain, diarrhea, headache, dizziness.

Spill cleanup:

• Small spills: Sweep up carefully (avoid dust generation). Place in clean, dry, labeled container. Wash area with water (but do not release wash water to the environment – collect as hazardous waste).

• Large spills: Evacuate area. Wear appropriate PPE. Cover spill (dry sand, vermiculite). Collect in approved hazardous waste containers.

• Never wash spill into sewers or water bodies with water (very toxic – environmental disaster).

• Disposal: Dispose of as hazardous waste (due to copper content). Recovery (copper recycling) is the preferred method. Incineration or landfill (only at licensed facilities).

12. Regulatory Status

13. Transport Information (for Pentahydrate)

Note: Anhydrous copper sulfate (CAS 7758-98-7) does not have a UN number in most cases, but can be classified similarly to pentahydrate. Pentahydrate is the most common commercial form.

14. Synonyms and Common Names

• English: Copper Sulfate, Cupric Sulfate, Cupric Sulfate Pentahydrate, Blue Vitriol, Bluestone, Blue Stone, Copper(II) Sulfate, Blue Copper

• German: Kupfersulfat, Kupfer(II)-sulfat, Blaustein, Vitriol

• French: Sulfate de cuivre, Sulfate de cuivre(II), Vitriol bleu

• Spanish: Sulfato de cobre, Sulfato cúprico, Vitriolo azul, Piedra azul

• Mineral names: Chalcanthite (pentahydrate mineral), Bonattite (trihydrate), Boothite (heptahydrate), Chalcosyanite

• Trade names: CP (Crystal Powder), Blue Copper, CuSO₄, Coppersan (agricultural product), Bordeaux mixture component

15. Copper Sulfate Pentahydrate vs. Anhydrous – Comparison

16. Frequently Asked Questions (FAQs)

Q1: What is copper sulfate and what is it used for?
A1: Copper sulfate (CuSO₄·5H₂O) is the most common copper salt. It appears as bright blue crystals and is known as "blue vitriol" or "bluestone." Main uses: agriculture as a fungicide (Bordeaux mixture), animal feed additive (growth promoter), swimming pool algaecide, mining (mineral separation), metal plating, and laboratory reagent. Approximately 75% of production is used in agriculture.

Q2: Is copper sulfate safe for humans?
A2: Copper sulfate is toxic if swallowed (LD₅₀ 300–500 mg/kg). Copper poisoning symptoms: nausea, vomiting (may be blue/green), abdominal pain, diarrhea, headache. Large amounts can cause liver and kidney damage, even death. Causes serious eye damage. Proper PPE is required for industrial use. Diluted solutions for household use (e.g., low concentrations in pools) are safe within specified limits.

Q3: Why is copper sulfate blue?
A3: Copper sulfate pentahydrate (CuSO₄·5H₂O) is blue due to four water molecules coordinated around the copper ion. These water molecules absorb specific wavelengths of light (especially red and yellow), causing the blue color to be seen (d-d transitions). The anhydrous form (without water) is gray-white to pale green. When heated, it loses water and turns from blue to white – a characteristic property used for water determination.

Q4: How is copper sulfate used in animals?
A4: Copper sulfate is used in animal husbandry for three main purposes: (1) Feed additive: Growth promoter for poultry and swine (improves feed conversion ratio, 5–10% faster growth). (2) Copper deficiency treatment: Anemia, bone abnormalities, nervous system disorders. (3) Foot bath: Treatment of foot rot (Fusobacterium necrophorum) in cattle, sheep, and goats using 5–10% solution.

Q5: Is copper sulfate soluble in water?
A5: Yes, copper sulfate has very high solubility in water. Approximately 32 grams dissolve in 100 mL of water at 20°C. At 100°C, up to 203 grams/100 mL (extremely high solubility). The solution is blue. It is insoluble or slightly soluble in ethanol and acetone.

Q6: Why is copper sulfate hazardous to the environment?
A6: Copper sulfate is very toxic to aquatic organisms. Even at very low concentrations (0.01 mg Cu/L), it has lethal effects on fish, algae, water fleas (Daphnia magna), and other invertebrates. It is not biodegradable, persists in soil and water, and can bioaccumulate. Therefore, it must never be discharged into surface waters, ponds, rivers, or sewers. Its use and disposal are subject to strict environmental regulations.

Q7: Can copper sulfate be used as a fire extinguisher?
A7: No. Copper sulfate is non-flammable and is not used as a fire extinguisher. However, it may be present as an additive in some special fire extinguishing powders. In case of fire, use extinguishing media appropriate for the surrounding fire (water spray, dry chemical powder, CO₂, foam).

Q8: Is copper sulfate permitted as a food additive (E519)?
A8: No in the EU and Turkey (E519 is listed but its use is not permitted or very restricted). It may be used in very low concentrations as a trace element supplement (copper source) in some countries. However, it is not a permitted food additive for general food applications.

Q9: Why is copper sulfate called Bordeaux mixture?
A9: Bordeaux mixture is a mixture of copper sulfate and hydrated lime (calcium hydroxide) in water. It was developed in the 1880s in the Bordeaux region of France to combat downy mildew in vineyards. It is one of the oldest and most widely used fungicides. It is permitted in organic agriculture. Formulation: 1% copper sulfate + 1% hydrated lime + water (100 L).

Q10: How should copper sulfate be disposed of?
A10: Copper sulfate must be disposed of as hazardous waste due to its copper content and high aquatic toxicity. Never pour down sewers, surface waters, or trash bins. Preferred disposal methods: (1) Recovery – copper recovery via metallurgical processes. (2) Licensed hazardous waste incineration. (3) Licensed landfill (only after inertization – e.g., solidification/stabilization). Strict compliance with environmental regulations is required.

17. Summary Table – Key Specifications at a Glance

*This TDS is prepared in compliance with ISO 11014-1 format and is intended for agricultural specialists, animal husbandry professionals, chemists, water treatment engineers, mining engineers, and procurement personnel. Certificates of Analysis (CoA), Safety Data Sheets (SDS), and sample validation reports are available upon request.*