IRON OXIDE BLUE

Iron Oxide Blue is a synthetic inorganic pigment primarily composed of ferric ferrocyanide or related compounds. 
It's known for its vivid blue color and is widely used in coatings, plastics, cosmetics, and construction materials.

CAS Number: 14038-43-8
Synonyms:iPrussian BlueiBerlin Blue,Paris Blue,Milori Blue,Iron(III) hexacyanoferrate(II)
Ferric hexacyanoferrate

Introduction

Iron oxide pigments have been widely used across multiple industries for centuries, offering a range of color options, stability, and non-toxic properties. 
Among these, Iron Oxide Blue is a distinct pigment known for its brilliant blue hue, derived from a complex iron compound. 
It is not a simple iron oxide but typically a mixed metal compound, often associated with ferric ferrocyanide (Prussian Blue) or stabilized forms of blue-tinted iron complexes.

The use of blue pigments dates back to ancient civilizations, yet stable, vibrant, and non-toxic blue pigments remained scarce until the modern synthesis of iron-based blues. 
Iron Oxide Blue now plays a critical role in coatings, construction materials, plastics, cosmetics, and artistic applications. 
Its chemical stability, environmental safety, and deep coloration make it a preferred choice for formulators seeking high-performance, durable pigments.

Chemical Composition and Structure
Iron Oxide Blue is typically composed of iron(III) ferrocyanide (Fe4[Fe(CN)6]3), also known as Prussian Blue. 
It consists of iron in both +2 and +3 oxidation states, forming a crystalline cubic lattice that traps water molecules and ions. 
The presence of cyanide ligands in a coordination complex leads to a strong ligand-to-metal charge transfer, resulting in its intense blue coloration.

The crystalline structure is characterized by Fe-CN-Fe linkages that stabilize the overall compound. 
This structure allows for ion exchange, making Prussian Blue useful in medical applications as well. While pure iron oxides (Fe2O3 or Fe3O4) tend to exhibit red, yellow, or black hues, Iron Oxide Blue's unique structure gives it optical and chemical characteristics distinct from typical oxides.

Polymorphic forms and hydration levels can affect the pigment's tint strength, shade, and stability. Substitution of metal ions or introduction of stabilizers further modifies its performance characteristics.

Synthesis and Production Methods
The production of Iron Oxide Blue can be divided into two broad categories: synthetic and naturally derived. 
However, industrially relevant Iron Oxide Blue is primarily synthetic due to better purity and consistency.

Co-precipitation Method
This traditional method involves the reaction of ferric chloride with potassium ferrocyanide in an aqueous medium. 
The resulting ferric ferrocyanide precipitate is filtered, washed, and dried. 
Control over reaction parameters such as pH, temperature, and molar ratios allows tuning of particle size and color intensity.

Hydrothermal and Sol-Gel Techniques
Modern techniques such as hydrothermal synthesis allow for the development of nano-sized particles with enhanced surface area and improved optical properties. 
These methods involve high-temperature, high-pressure reactions in autoclaves.

Calcination and Stabilization
Post-synthesis, the pigment may be stabilized through calcination, often with additives like alumina or silica to enhance its durability. 
This step helps improve lightfastness, thermal stability, and dispersibility in various media.

Physical and Chemical Properties
Iron Oxide Blue pigments display a deep blue color due to their electronic structure. 
The key physical and chemical properties include:
Color Index: PB27 (Pigment Blue 27)
Density: ~1.8-2.2 g/cm³
Melting Point: Decomposes before melting
pH in Aqueous Suspension: Neutral to slightly acidic (5.0 - 7.0)
Oil Absorption: Moderate, around 30-50 g/100 g pigment
Thermal Stability: Stable up to ~250°C
Solubility: Insoluble in water and organic solvents
Microscopic examination reveals particle sizes typically in the range of 0.05 to 1 microns, enabling smooth dispersion in paint and polymer matrices. 
The pigment resists UV degradation and shows minimal photochemical reactivity, enhancing its longevity in exterior applications.

Applications
Iron Oxide Blue's applications span numerous industries:

Paints and Coatings
Used in industrial, decorative, and automotive paints due to its UV stability and vivid color. 
It offers excellent coverage and weather resistance.

Plastics and Polymers
Added to polyolefins, PVC, and polystyrene to provide coloration without compromising polymer stability. 
Requires proper dispersion techniques.

Ceramics and Construction Materials
Used to color concrete, tiles, and bricks. Resistant to alkaline environments found in cementitious materials, especially when stabilized.

Cosmetics and Pharmaceuticals
Approved for use in eye shadows, eyeliners, and therapeutic drugs like radiological decorporation agents. 
Must meet purity and particle size specifications.

Artistic and Cultural Heritage Applications
Used in restoration of historical artworks and monuments. 
Preferred for its non-toxic profile and color consistency.

Performance and Compatibility
Iron Oxide Blue demonstrates high performance across various media:
Dispersibility: Good in water-based and solvent-based systems
Compatibility: Compatible with resins, polymers, and cements
Durability: High resistance to weathering, acid rain, and UV radiation
In composite systems, coupling agents and dispersing additives may be used to enhance stability and avoid pigment flooding or floating.

Advantages and Limitations
Advantages:
Vivid, intense blue color
High tinting strength
Non-toxic and environmentally safe
UV and chemical resistance
Limitations:
Limited thermal stability compared to other pigments
Possible fading in strong alkali environments
Cyanide ligands, though stable, require stringent control in synthesis

SAFETY INFORMATION ABOUT IRON OXIDE BLUE

First aid measures:
Description of first aid measures:
General advice:
Consult a physician. 
Show this safety data sheet to the doctor in attendance.
Move out of dangerous area:
 
If inhaled:
If breathed in, move person into fresh air. 
If not breathing, give artificial respiration.
Consult a physician.
In case of skin contact:
Take off contaminated clothing and shoes immediately. 
Wash off with soap and plenty of water.
Consult a physician.
 
In case of eye contact:
Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician.
Continue rinsing eyes during transport to hospital.
 
If swallowed:
Do NOT induce vomiting. 
Never give anything by mouth to an unconscious person. 
Rinse mouth with water. 
Consult a physician.
 
Firefighting measures:
Extinguishing media:
Suitable extinguishing media:
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Special hazards arising from the substance or mixture
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas
 
Advice for firefighters:
Wear self-contained breathing apparatus for firefighting if necessary.
Accidental release measures:
Personal precautions, protective equipment and emergency procedures
Use personal protective equipment. 
 
Avoid breathing vapours, mist or gas. 
Evacuate personnel to safe areas.
 
Environmental precautions:
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
 
Methods and materials for containment and cleaning up:
Soak up with inert absorbent material and dispose of as hazardous waste. 
Keep in suitable, closed containers for disposal.
 
Handling and storage:
Precautions for safe handling:
Avoid inhalation of vapour or mist.
 
Conditions for safe storage, including any incompatibilities:
Keep container tightly closed in a dry and well-ventilated place. 
Containers which are opened must be carefully resealed and kept upright to prevent leakage.
Storage class (TRGS 510): 8A: Combustible, corrosive hazardous materials
 
Exposure controls/personal protection:
Control parameters:
Components with workplace control parameters
Contains no substances with occupational exposure limit values.
Exposure controls:
Appropriate engineering controls:
Handle in accordance with good industrial hygiene and safety practice.
Wash hands before breaks and at the end of workday.
 
Personal protective equipment:
Eye/face protection:
Tightly fitting safety goggles. 
Faceshield (8-inch minimum). 
Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
 
Skin protection:
Handle with gloves. 
Gloves must be inspected prior to use. 
Use proper glove
removal technique (without touching glove's outer surface) to avoid skin contact with this product. 
Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. 
Wash and dry hands.
 
Full contact:
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
Splash contact
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
It should not be construed as offering an approval for any specific use scenario.
 
Body Protection:
Complete suit protecting against chemicals, The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.
Respiratory protection:
Where risk assessment shows air-purifying respirators are appropriate use a fullface respirator with multi-purpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls. 
 
If the respirator is the sole means of protection, use a full-face supplied air respirator. 
Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Control of environmental exposure
Prevent further leakage or spillage if safe to do so. 
Do not let product enter drains.
Discharge into the environment must be avoided.
 
Stability and reactivity:
Chemical stability:
Stable under recommended storage conditions.
Incompatible materials:
Strong oxidizing agents:
Hazardous decomposition products:
Hazardous decomposition products formed under fire conditions. 
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas.
 
Disposal considerations:
Waste treatment methods:
Product:
Offer surplus and non-recyclable solutions to a licensed disposal company. 
Contact a licensed professional waste disposal service to dispose of this material.
Contaminated packaging:
Dispose of as unused product