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Product Name: Letrozole
Chemical Name: 4,4’-(1H-1,2,4-Triazol-1-ylmethylene)dibenzonitrile
Synonyms: Femara
CAS Number: 112809-51-5
Recommended Use: Aromatase inhibitor for pharmaceutical applications
Manufacturer Information: Refer to packaging for supplier details
Emergency Contact: Local poison control center or healthcare provider
Address: See manufacturer’s packaging
Telephone: Manufacturer’s and distributor’s emergency lines
Classification: Harmful if swallowed or inhaled. May cause reproductive toxicity or developmental toxicity. Eye and skin irritant.
GHS Label Elements: Warning; health hazard pictogram; exclamation mark symbol
Signal Word: Warning
Hazard Statements: May cause damage to organs. Harmful to aquatic life with long lasting effects.
Precautionary Statements: Avoid breathing dust or particles. Avoid contact with skin, eyes, and clothing. Wash hands thoroughly after handling. Do not eat, drink, or smoke when using product.
Other Hazards: May form harmful dust when handling tablets or powders. Use personal protective equipment (PPE) to minimize risk.
Chemical Name: Letrozole
Molecular Formula: C17H11N5
Concentration: >98% active pharmaceutical ingredient
Impurities: Trace residual synthesis byproducts and organic solvents can remain under 0.1%.
Additives: Pharmaceutical tablets often include excipients such as lactose, starch, and magnesium stearate, but these are not found in pure API.
CAS Number: 112809-51-5
Inhalation: Move affected person to fresh air. Seek medical attention for difficulty breathing or persistent symptoms.
Skin Contact: Remove contaminated clothing and rinse skin thoroughly with water. Seek medical attention for irritation.
Eye Contact: Flush open eyes immediately with plenty of water for at least 10 minutes. Remove contact lenses if easy to do. Get medical help quickly.
Ingestion: Rinse mouth thoroughly with water. Do not induce vomiting. Call physician or poison control for medical guidance.
Acute Symptoms and Effects: Nausea, dizziness, headache, or respiratory effects after exposure require prompt assessment by healthcare professional.
Suitable Extinguishing Media: Use foam, dry chemical, carbon dioxide, or water spray.
Unsuitable Extinguishing Media: Avoid high-pressure water streams, as they may scatter dust.
Specific Hazards: Thermal decomposition or combustion can release toxic carbon/nitrogen oxides.
Protective Equipment: Full protective gear and positive-pressure self-contained breathing apparatus recommended.
Fire-Fighting Advice: Stay upwind, keep out of smoke clouds, and avoid runoff entering drains or watercourses.
Personal Precautions: Use appropriate personal protective equipment (nitrile gloves, safety glasses, laboratory coat, respiratory protection if dust forms).
Environmental Precautions: Prevent spillage from entering drains, surface water, or soil.
Containment Methods: Sweep up powder carefully without creating dust. Collect in closed containers for disposal.
Decontamination Methods: Clean the area with soap and water following removal. Properly vent confined spaces where dust could accumulate.
Handling: Work in a well-ventilated area. Avoid creating dust. Use local exhaust or fume hoods when handling dry powder. Wear suitable protective gear. Direct handling of tablets should be minimized outside original packaging.
Storage: Store at room temperature (15-30°C), away from direct sunlight and incompatible materials such as strong oxidizers and acids. Secure in tightly closed containers. Lock up storage areas to prevent unauthorized access. Maintain good industrial hygiene by keeping work areas clean.
Exposure Limits: No official workplace exposure limits established, but minimize exposure as for all pharmaceutical compounds.
Engineering Controls: Allow only in fume hood or with sufficient mechanical exhaust.
Personal Protective Equipment: Wear nitrile gloves, eye protection, lab coat. In situations with risk of inhalation, a NIOSH-approved respirator suited for dust should be used. Remove contaminated clothing after use.
Hygiene Measures: Wash hands thoroughly after handling. Do not eat or drink in work areas.
Appearance: White to pale yellow crystalline powder or solid
Odor: Odorless or faint chemical
pH: Not applicable for solid
Melting Point: Approximately 184-185°C
Boiling Point: Decomposes before boiling
Solubility: Slightly soluble in water, freely soluble in acetone, methanol, and ethanol
Vapor Pressure: Negligible at room temperature
Density: About 1.3 g/cm3
Flash Point: Not readily flammable (above 200°C)
Partition Coefficient (log P): Between 2.4 and 2.6
Stability: Stable under recommended storage conditions
Stability: Chemically stable at room temperature and under normal environmental conditions
Reactivity: Unreactive with most materials in typical pharmaceutical storage
Conditions to Avoid: Avoid heat, moisture, and strong oxidizing or reducing agents
Hazardous Decomposition Products: Carbon monoxide, nitrogen oxides, cyanide compounds during combustion or thermal breakdown
Polymerization: Not known to occur
Acute Toxicity: Oral LD50 in rats estimated at >2000 mg/kg. Potential toxicity to reproductive organs. Could cause mild to moderate irritation to eyes and skin.
Chronic Effects: Animal studies show possible disruption of hormones and impact on fertility. Long-term or repeated exposure increases health risks, including bone demineralization.
Carcinogenicity: Not classified as carcinogenic to humans but long-term data is limited.
Reproductive Toxicity: Letrozole can disrupt ovulation and embryo implantation.
Routes of Exposure: Inhalation, skin contact, ingestion.
Symptoms: Drowsiness, headache, nausea, hormone imbalance.
Ecotoxicity: Harmful to aquatic life. Prudent measures should be taken to avoid release into the environment.
Persistence and Degradability: Not rapidly biodegradable. Remains in water and soil for extended periods.
Bioaccumulation: Moderate potential for accumulation in organisms due to lipophilicity.
Mobility in Soil: Moderate mobility through soil and sediment. Avoid contamination of natural water sources.
Other Adverse Effects: Pharmaceuticals can disturb hormonal systems in wildlife if allowed to enter rivers or lakes.
Waste Disposal Method: Dispose of in accordance with local, regional, national, and international regulations as pharmaceutical waste. Incineration in approved facilities recommended.
Contaminated Packaging: Safely dispose of containers as hazardous waste. Clean containers thoroughly before reuse or recycling.
Special Considerations: Avoid disposed waste entering municipal drains or water systems. Clearly label containers for disposal.
UN Number: Not classified as dangerous goods for transport under UN, ADR, IATA, or IMDG codes
Proper Shipping Name: Not regulated for transport
Transport Hazard Class: Not classified
Packing Group: Not assigned
Special Transport Precautions: Prevent damage to packaging, limit vibration or crushing. Secure to avoid spillage.
Safety, Health, and Environmental Regulations: Subject to pharmaceutical handling regulations in the US (OSHA), EU (REACH), and other jurisdictions. Must comply with hazardous substance management laws.
Inventory Listings: Active ingredients registered for pharmaceutical use only, not for technical or commercial applications outside regulated framework.
Other Regulations: May be subject to workplace safety training and exposure monitoring. Packaging should include required hazard labeling and safety information.
Restrictions: Prescription-only medication for intended patients. Professionals handling the API should use best practices for hazardous materials management.
