Material Safety Data Sheet: Bismuth-Zinc Alloy

Identification

Product Name: Bismuth-Zinc Alloy
Synonyms: Bismuth Zinc Alloy, BiZn
CAS Number: 7440-42-8 (Bismuth), 7440-66-6 (Zinc)
Recommended Uses: Low-melting alloys, electrical fuses, fire safety devices, casting
Manufacturer: Major chemical and nonferrous metal suppliers
Contact Information: Emergency contact numbers available via supplier or regional poison control

Hazard Identification

Classification: Not classified as hazardous under GHS. Potential health effects stem from metal dust or fumes, not from solid alloy.
Signal Word: None
Hazard Statements: Fumes can cause respiratory irritation. Hot molten alloy can cause severe burns.
Pictograms: None required for bulk alloy; use for fume exposure.
Precautionary Statements: Avoid breathing dust and fume. Prevent eye and skin contact with molten metal. Use adequate ventilation.
Other Hazards: Zinc fumes may lead to metal fume fever. Spilled molten alloy solidifies rapidly.

Composition / Information on Ingredients

Chemical Composition:
- Bismuth: 40–70% (CAS No. 7440-42-8)
- Zinc: 30–60% (CAS No. 7440-66-6)
Impurities: Trace amounts of lead, cadmium, or other metals may occur, typically less than 0.1% each.

First Aid Measures

Inhalation: Move to fresh air. Seek medical attention if symptoms like coughing or shortness of breath develop after exposure to fumes.
Skin Contact: Immediately cool burns with running water. Do not attempt to remove solidified metal from skin. Seek emergency medical help for burns.
Eye Contact: Rinse eyes gently with water for at least 15 minutes. Remove contact lenses if present and easy to do. Get prompt medical assistance.
Ingestion: Rinse mouth. Do not induce vomiting. Get medical advice if large amounts are swallowed.
Symptoms: Metal fume fever (zinc): chills, fever, muscle aches. Severe burns from molten alloy possible.

Fire-Fighting Measures

Suitable Extinguishing Media: Dry sand, class D fire extinguisher, or graphite powder for metal fires. Do not use water on molten metal.
Specific Hazards: Fumes containing zinc oxide and bismuth oxide develop at high temperatures. Water contacts can cause violent splattering of molten metal.
Protective Equipment: Firefighters need full protective gear and NIOSH-approved self-contained breathing apparatus.
Thermal Decomposition Products: Metal oxides; may irritate the respiratory tract.

Accidental Release Measures

Personal Precautions: Wear protective gloves and safety glasses. Avoid breathing dust or fume if cleaning fine particles.
Environmental Precautions: Prevent spilled alloy from reaching drains or waterways. Collect spillage for disposal or recycling.
Cleanup Methods: For solid alloy, pick up mechanically. Allow molten spills to cool before removal. Manage dust using wet methods or HEPA vacuum.

Handling and Storage

Handling: Wear protective clothing when melting or pouring. Only melt alloy in well-ventilated spaces or under local exhaust.
Storage: Store as solid bars or ingots in dry, well-ventilated conditions. Keep away from flammable materials or incompatible substances like strong acids or bases.
Incompatibility: Strong oxidizers, acids, and alkalis can react with the alloy components.
Hygiene Practices: Wash hands thoroughly after working with alloy. Avoid eating, drinking, or smoking in areas where alloy is worked.

Exposure Controls and Personal Protection

Occupational Exposure Limits: Bismuth: Not established. Zinc: OSHA PEL (as zinc oxide fumes) 5 mg/m³ TWA.
Engineering Controls: Use local exhaust when melting or processing the alloy at high temperatures.
Respiratory Protection: Use N95 or P100 for dust. Use air-purifying respirators if fume exposure occurs.
Eye Protection: Safety glasses or goggles. Face shield for pouring or melting.
Skin Protection: Heat-resistant gloves and protective workwear.
General Protection: Have eyewash stations and safety showers where the alloy is handled.

Physical and Chemical Properties

Appearance: Silver-gray metallic solid, shiny when freshly cut.
Odor: None in solid form.
Melting Point: 95-200°C (depends on exact composition)
Boiling Point: Above 900°C
Density: 7.0–9.8 g/cm³
Solubility: Insoluble in water.
Vapor Pressure: Negligible at ambient temperature.
Other Properties: Alloy is stable and non-flammable as a solid. Can produce metal oxides when heated.

Stability and Reactivity

Chemical Stability: Stable under normal conditions.
Reactivity: Not reactive in solid state. Fumes form at high temperatures.
Hazardous Reactions: Reacts with strong acids, releasing hydrogen gas.
Hazardous Decomposition: Bismuth oxide and zinc oxide form if strongly heated.
Incompatible Materials: Strong oxidizers, strong acids, bases.

Toxicological Information

Acute Toxicity: Low for solid alloy. Inhalation of zinc oxide fumes leads to metal fume fever.
Chronic Effects: No known chronic effects in occupational settings at recommended exposures.
Routes of Exposure: Inhalation (fume, dust), skin, eye contact.
Symptoms: Fume exposure: flu-like symptoms, metallic taste, cough, chest discomfort.
Carcinogenicity: No components classified as carcinogens by IARC, NTP, or OSHA.
Other Information: Bismuth compounds minimally toxic by ingestion, but not recommended; zinc essential in small amounts.

Ecological Information

Ecotoxicity: Zinc harmful to aquatic life with long-lasting effects. Bismuth considered relatively benign.
Bioaccumulation: Limited, but zinc may accumulate in aquatic organisms.
Persistence and Degradability: Metals persist in the environment, do not degrade.
Mobility in Soil: Low, as alloy is insoluble in water.
Additional Information: Prevent releases to the environment through proper handling and disposal.

Disposal Considerations

Disposal Methods: Recycle spent alloy when possible. Dispose of unused alloy and contaminated PPE as non-hazardous solid metal waste if allowed by local regulations.
Waste Code: Not classified as hazardous waste in most regions.
Special Precautions: Prevent uncontrolled melting or powder formation during disposal.

Transport Information

UN Number: Not regulated for transport as a hazardous material.
Proper Shipping Name: Metal Alloy, Non-Hazardous
Transport Hazard Class: None
Packing Group: None
Special Precautions: Protect ingots and bars from damage and moisture. Use sealed containers for powder.

Regulatory Information

TSCA Status: Listed.
REACH Status: Registration required for quantities above threshold.
SARA Title III: Zinc listed; bismuth not subject to Section 313 reporting.
WHMIS Classification: Not controlled (Canada).
Labeling Requirements: No special labeling for solid alloy, label containers if dust or powders present.
Other Regulations: Workplace exposure to fume or dust regulated under OSHA and ACGIH guidelines.