Fly ash is a fine residue resulting from the burning of powdered coal at high temperatures. The most common sources of Fly Ash are electric power generating stations. Fly Ash has become the predominant pozzolan in use throughout the world due to performance and economic factors. The main content of Fly Ash is silica. There are 2 types of Fly Ash Class F and Class C. The types are differentiated base on the sum of Silicon Dioxide (Sio2) + Aluminum Oxide (AI2O3) + Iron Oxide (Fe2O3). If the sum of this is greater than or equal to 70% it is called Class F Fly Ash and if the percentage is greater than or equal to 50% it is called Class C Fly Ash. Economic Benefits: It replaces Portland cement up to 20 to 50%.

Technical Benefits on Fresh Concrete:

  • Improves workability
  • Improves pumpability
  • Extends time of set
  • Decreases bleeding
  • Decreases earl rate of strength pain
  • Reduces heat evolution

Technical Benefits on Hardened Concrete:

  • Increases strength (long term)
  • Improves durability
  • Decreases permeability
  • Reduces alkali aggregate expansion
  • Has variable effects on creep and shrinkages

Section 1: Product/ Company Information

Identify : Fly Ash, Class F, ASTM C 618 / BS 3892
Country of Origin : India

Section 2: Composition Information


CAS Number

Percent by Weight

Silicon Dioxide (SiO2)



Aluminum Oxide (Al2O3)



Iron Oxide (Fe2O3)



Titanium Oxide (TiO2)



Calcium Oxide (CaO)



Potassium Hydroxide (KOH)



Sulfur Trioxide (SO3)



Section 3: Hazard Identification

Potential Health Effects: Potential health effects may vary depending upon the duration and degree of exposure. To reduce or eliminate health hazards associated with this product, use exposure control personal protection methods as described in Section 12.

Eye Contact: (Acute/ Chronic) Exposure to airborne dust may cause immediate or delayed irritation inflammation of the cornea.

Inhalation: (Acute) Breathing dust may cause nose, throat or lung irritation.

Ingestion: Do not ingest Ash. Although ingestion of small quantities of ash is not known to be harmful, large quantities can cause distress to the digestive tract.

Inhalation (Chronic): Risk of injury depends on duration and level of exposure.

Silicosis: This product contains crystalline silica. Prolonged or repeated inhalation of respirable crystalline silica from this product can cause silicosis, a seriously disabling and fatal lung disease.

Carcinogenicity: Ash is not listed as a carcinogen by IARC, however, ash contains trace amounts of crystalline silica, which is classified as a known human carcinogen.

H.M.I.S ratings: Health -1           Flammability – 0          Reactivity – 0

Section 4: Emergency and First Aid

Eyes: Immediately flush eye thoroughly with water. Get medical attention if irritation persists.

Skin: Wash with cool water and mild skin detergent. Seek medical attention for rashes or irritation.

Inhalation: Remove person to fresh air. If breathing is difficult, administer oxygen. If not breathing give artificial respiration. Seek medical help if coughing and other symptoms do not subside.

Ingestion: Do not induce vomiting. If conscious, have the victim drink plenty of water and call a physician if discomfort is experience.

Section 5: Accidental Release Measures

Use clean- up methods that do not disperse dust into air. Avoid inhalation of dust and contact with eyes. Use exposure control and personal protection methods as described in Section 12.

Section 6: Physical/ Chemical Data

Boiling Point  


Specific Gravity (II20=1.0)  

2.0 - 2.9

Vapor Pressure      

Not applicable


Slightly (<5%)


Gray / black or brown/ tan powder


No odor

Physical State       


Vapor Density 

Not applicable

Ph (in water)     


Section 7: Fire and Explosion Hazard Data

Flash Point  


Auto Ignition Temperature

Not combustible         

Flammable Limits


Extinguishing Media     

Not Combustible

Hazardous Combustion Products


Lower Explosive Limit    


Upper Explosive Limit 


Special Fire Fighting Procedure


Unusual Fire Explosion Hazards


Section 8: Stability and Reactivity Data


 Product is stable

Incompatibility (Materials to Avoid)        

Acids, ammonium salts and aluminum metal

Hazardous Decomposition     

Will not Occur

Hazardous Polymerization   

Will not occur

Section 9: Handling and Storage

Handle and store in a manner so that airborne dust does not exceed applicable exposure limits. Use adequate ventilation and dust collection. Use exposure control and personal protection methods as described in Section 12.

Section 10: Toxicological Information

Conditions aggravated by exposure: Eye disease, Skin disorders and Chronic conditions.

Section 11: Exposure Control / Personal Protection

Respiratory Protection: Use local exhaust or general dilution to control dust levels below applicable exposure limits. Minimize of dust into the air. Use appropriate NIOSH approved respiratory protection for respirable crystalline silica.

Eye Protection: Wear safety glasses with side shields or goggles to avoid contact with eyes. In extremely dusty environments and unpredictable environments, wear tight- fitting unvented or indirectly vented goggles to avoid eye irritation or injury.

Skin Protection: Wear gloves, boot covers and protective clothing impervious to water to prevent skin contact.

Section 12: Disposal Considerations

All disposal methods must be in accordance with all Federal/ Provincial and local laws and regulations. Regulations may vary in different locations. Waste characterization and compliance with applicable laws are the responsibility solely of the waste generator.

Section 13: Transportation Data

This product is not classified as hazardous under DOT or TDG regulations.

Section 14: Other Information

Status Under US OSHA Hazard Communication Rule 29 CFR 1910.1200: Silica is considered as Hazardous Chemical under this regulation and should be included in the employer’s hazard communication program.

Status under CERCLA / Superfund,40 CFR and 302: NOT LISTED

Hazard Category under SARA (Title111), Section 311 and 312: Silica qualifies as a hazardous substance with delayed health effects.

Status under SARA (Title111), Section 313: Not subjecting to reporting requirements under section 313.

Section 15: Other Information

The information and recommendation contained herein are based upon data believed to be correct. However, no guarantee or warranty of any kind, express or implied, is made with respect to the information contained herein. It is the user’s obligation to determine the conditions of safe use of this product.

Fly Ash