Material Safety Data Sheet for Silicon Dioxide

Identification

Product Name: Silicon Dioxide
Chemical Formula: SiO₂
Synonyms: Silica, Quartz, Cristobalite, Amorphous Silica
CAS Number: 7631-86-9
Recommended Use: Fillers, abrasives, glass manufacturing, food additive, filtration, rubber products
Manufacturer/Supplier: Contact details available on product label
Emergency Number: Provided by supplier

Hazard Identification

Classification: Not classified as hazardous according to GHS for the general form, but respirable crystalline silica classified as carcinogenic (IARC Group 1)
Hazard Statements: Prolonged inhalation of respirable dust may cause lung disease including silicosis and increase risk of lung cancer
Signal Word: Danger (for respirable crystalline silica)
Precautionary Statements: Avoid breathing dust; use only in well-ventilated areas; wear respiratory protection if dust generated
Routes of Exposure: Inhalation is primary; eye or skin contact may cause irritation
Symptoms: Coughing, difficulty breathing, lung irritation, possible chronic effects after prolonged exposure

Composition / Information on Ingredients

Chemical Name: Silicon Dioxide
Concentration: 98% or higher
Impurities: May contain traces of quartz, cristobalite, or tridymite depending on source
Hazardous Components: Quartz (respirable fraction: hazardous by inhalation)

First Aid Measures

Inhalation: Move exposed individual to fresh air quickly; seek medical attention if symptoms such as persistent cough, wheezing, or breathing difficulties develop
Skin Contact: Wash with soap and water; remove contaminated clothing; seek medical attention for irritation or persistent redness
Eye Contact: Flush eyes with plenty of clean water for at least 15 minutes, lifting upper and lower eyelids occasionally; seek medical help if irritation persists
Ingestion: Rinse mouth with water if large quantities ingested; seek medical attention in case of discomfort or unexpected symptoms
Personal Protection for First Aiders: Use gloves and eye protection, provide ventilation to avoid inhalation of dust during response

Fire-Fighting Measures

Suitable Extinguishing Media: This substance is not flammable; use media appropriate to surrounding fire such as water spray, foam, dry powder, or CO₂
Unsuitable Extinguishing Media: None known for this product
Specific Hazards: No hazardous combustion products known; material remains stable under normal fire conditions
Protective Equipment for Firefighters: Wear standard firefighting gear including gloves, eye/face protection, and self-contained breathing apparatus if dust present
Advice: Prevent dust formation, limit entry of run-off from firefighting into waterways

Accidental Release Measures

Personal Precautions: Wear dust mask or respirator suitable for silica dust; use protective gloves and safety goggles; ensure adequate ventilation
Environmental Precautions: Avoid discharge of large amounts into drains or water sources by containing the spread
Methods for Cleanup: Gently sweep up or vacuum material to prevent dust cloud formation; use wet methods if practical; collect in labeled containers for proper disposal
Precautions for Others: Keep unnecessary personnel away; inform responsible authorities if release occurs in public areas

Handling and Storage

Handling: Minimize dust generation and accumulation; use local exhaust systems where dust is produced; avoid eating, drinking, or smoking in work areas
Storage: Store in dry, well-ventilated area away from incompatible substances; keep container tightly closed; avoid contact with hydrofluoric acid and strong oxidizers
Occupational Hygiene: Wash hands and exposed skin thoroughly after handling; remove contaminated clothing before leaving work area
Special Considerations: Prevent container damage and leaks; avoid mechanical impact or disturbance of crystalline material

Exposure Controls and Personal Protection

Occupational Exposure Limits: OSHA PEL for respirable crystalline silica: 50 μg/m³; NIOSH REL: 50 μg/m³ (10-hour TWA); ACGIH TLV for quartz (respirable fraction): 0.025 mg/m³
Engineering Controls: Use local exhaust ventilation, enclosures, or other engineering methods to keep airborne levels below limits
Personal Respiratory Protection: Wear NIOSH-approved particulate respirators if airborne concentrations may exceed occupational limits
Eye Protection: Use safety goggles or glasses with side-shields
Skin Protection: Wear gloves and coveralls or other body protection as needed
Hand Protection: Use industrial-grade gloves when handling
Hygiene: No food or drinks in work area; always wash before breaks and after work

Physical and Chemical Properties

Physical State: Solid; powder, granules, or crystals
Color: White or colorless
Odor: Odorless
Melting Point: ~1710°C
Boiling Point: Sublimes at ~2230°C
Density: 2.2-2.7 g/cm³
Solubility: Insoluble in water; soluble in hydrofluoric acid
Vapor Pressure: Not applicable
pH: 6.5 (5% slurry in water)
Particle Size: Varies by product; dust fraction hazardous if inhaled

Stability and Reactivity

Chemical Stability: Stable under normal storage conditions
Reactivity: Moderately reactive with strong acids, especially hydrofluoric acid (HF); slowly dissolves in hot concentrated alkalis
Hazardous Reactions: Contact with HF produces toxic silicon tetrafluoride gas
Hazardous Decomposition Products: None under normal conditions
Conditions to Avoid: Avoid creating or inhaling dust; avoid high temperature processing in strong acid environments
Materials to Avoid: Strong oxidizers and HF

Toxicological Information

Acute Toxicity: Silicon dioxide is considered low in acute oral and dermal toxicity
Chronic Toxicity: Prolonged and repeated inhalation of respirable crystalline dust may cause silicosis, an irreversible lung disease; increased risk of lung cancer recognized by IARC, OSHA, and NTP
Routes of Exposure: Mainly inhalation; rare effects from ingestion or skin contact
Irritation: Dust may irritate eyes, skin, and respiratory tract
Carcinogenicity: IARC Group 1 carcinogen (crystalline silica, inhaled from occupational sources)
Mutagenicity: No significant genetic or reproductive effects identified
Target Organs: Lungs primarily affected by chronic exposure

Ecological Information

Ecotoxicity: Silicon dioxide is a naturally occurring mineral; not toxic to aquatic or terrestrial organisms in bulk form
Persistence and Degradability: Stable, non-degradable
Bioaccumulation Potential: Does not bioaccumulate
Mobility in Soil: Remains in particulate form; not mobile in natural environment, settles out of water easily
Additional Ecological Effects: No known long-term adverse effects on the environment beyond dust generation

Disposal Considerations

Disposal Methods: Dispose of in accordance with local, regional, and national regulations; landfill is common route for non-contaminated material; do not discharge to water or drains
Container Disposal: Empty containers should be reused, recycled, or disposed of after cleaning; avoid dust release during handling
Special Precautions: Label wastes accurately for silica content; consult local environmental authorities for large quantities

Transport Information

UN Number: Not regulated as a hazardous material for transport purposes
UN Proper Shipping Name: Not applicable
Transport Hazard Class: Not classified
Packing Group: Not assigned
Environmental Hazards: Not classified as environmentally hazardous for road, rail, sea, or air transport
Transport Precautions: Use standard containers; minimize dust generation during loading and unloading; secure packaging against spills or dispersal in transit

Regulatory Information

Occupational Safety: OSHA, NIOSH, and ACGIH occupational exposure limits apply to respirable fraction of crystalline silica
Carcinogen Status: Listed by IARC as Group 1 carcinogen; NTP and OSHA list as known human carcinogen (respirable crystalline form)
TSCA Inventory: Listed
EINECS/ELINCS Number: 231-545-4
Other Regulations: Complies with EU REACH requirements; not classified as dangerous according to Regulation (EC) No 1272/2008 for non-respirable forms
Labeling Requirements: Hazard statements and precautionary advice required for dust-generating forms
Special Local Considerations: Some jurisdictions may impose stricter controls on airborne crystalline silica