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Product Name: L-Cysteine
Chemical Formula: C3H7NO2S
Synonyms: 2-Amino-3-mercaptopropionic acid, Cysteine
CAS Number: 52-90-4
Molecular Weight: 121.16 g/mol
Recommended Uses: Laboratory chemicals, food additive, pharmaceutical ingredient, personal care products
Manufacturer Contact: Contact details for manufacturer or distributor must be accessed from current product label or invoice
Emergency Phone Number: Provide emergency details linked to specific supplier or manufacturer
Product Identifier: L-Cysteine, powder or crystalline solid
Classification: Not classified as hazardous under GHS criteria. Most exposures occur in either laboratory or production environments.
Label Elements: No symbol or signal word required for standard handling. Stated precautionary measures for chemical irritation recommended.
Potential Health Effects: Inhalation may cause mild respiratory irritation. Eye contact may produce redness, tearing, or mild discomfort. Skin contact can cause short-lived irritation or dryness. Ingestion rarely results in harm but taking large amounts may lead to gastrointestinal discomfort.
Environmental Hazards: L-Cysteine is not classified as a marine pollutant and does not significantly threaten aquatic environments at current industrial levels.
Chemical Identity: L-Cysteine
Purity: Proprietary blends cannot exceed trace percentages; typical assay greater than 99% pure L-Cysteine
Other Ingredients: No other hazardous components present above regulated thresholds
Impurities: Minor impurities below regulatory concern
Inhalation: Move to fresh air promptly. Seek medical attention if symptoms (respiratory irritation, coughing) do not subside quickly.
Skin Contact: Remove contaminated clothing. Rinse skin with plenty of water. Soap may help clear any residue. Persistent rash or irritation calls for medical advice.
Eye Contact: Rinse eyes gently with lukewarm water for fifteen minutes. Remove contact lenses cautiously if present. If discomfort persists, visit a health care provider.
Ingestion: Wash out mouth with water. Drink a glass of water to dilute. Monitor for adverse symptoms and consult a physician if necessary.
Most Important Symptoms and Effects: Mild irritation to eyes, skin, respiratory tract, or gastrointestinal system. Symptoms rarely escalate when handled with basic precautions.
Suitable Extinguishing Media: Water spray, CO2, dry chemical powder, foam
Unsuitable Extinguishing Media: Direct water jets on powder piles should be avoided to prevent spreading
Specific Hazards: L-Cysteine decomposes under intense heat to form sulfur oxides and nitrogen oxides that irritate eyes and lungs.
Protective Equipment: Firefighters should wear full protective gear and self-contained breathing apparatus.
Further Advice: Cool containers exposed to flames and move uninvolved containers away if safe. Clear area of unnecessary personnel.
Personal Precautions: Put on gloves, safety glasses, and a suitable dust mask. Do not touch or walk through spilled material unless necessary.
Environmental Precautions: Avoid letting the powder enter watercourses or drains. Sweep material into a suitable container for disposal.
Methods for Containment: Prevent formation of dust clouds. Confine spill with inert material.
Cleanup Procedures: Use non-sparking tools to gather powder. Clean area with soapy water to collect residue. Wash hands thoroughly after cleanup.
Safe Handling: Ensure good ventilation in work area. Minimize any dust creation. Do not eat, drink, or smoke while handling. Use proper protective equipment at all times.
Storage Conditions: Store in original container, tightly closed and dry. Protect from heat, direct sunlight, and moisture. Keep away from incompatible substances such as strong acids or oxidizers.
Extra Precautions: Restrict storage area to trained personnel. Do not store with food or drinks.
Occupational Exposure Limits: Not specifically regulated. Workplace exposure should follow general dust standards; nuisance dust threshold of 10 mg/m³ (total inhalable dust) typically applies.
Engineering Controls: General room ventilation recommended. For large-scale or industrial use, use local exhaust where possible.
Personal Protection: Protective gloves (nitrile or latex), safety goggles, laboratory coat or apron, dust mask (EN149 FFP1 or similar) when airborne particles may form. Wash hands after use.
Environmental Protection: Do not discharge waste into drains. Collect and dispose of waste material safely.
Appearance: White crystalline or powdery solid
Odor: Characteristically mild, similar to sulfur
Odor Threshold: Low, but not unpleasant
pH: 4.5 to 5.5 (1% solution in water)
Melting Point: Approximately 220°C
Boiling Point: Decomposes before boiling
Flash Point: Not established
Evaporation Rate: Not applicable
Flammability: Not classified as flammable
Upper/Lower Flammability Limits: Not applicable
Vapor Pressure: Negligible at room temperature
Vapor Density: No vapors under anticipated use
Specific Gravity: About 1.7 (water = 1)
Solubility in Water: Freely soluble
Partition Coefficient (log Pow): -2.49
Auto-Ignition Temperature: Not measured
Decomposition Temperature: About 240°C
Viscosity: Not applicable
Chemical Stability: Remains stable if stored in sealed containers, protected from moisture and excessive heat
Reactivity: May react with strong acids, strong bases, or oxidizing agents to release hazardous gases especially sulfur oxides
Conditions to Avoid: Exposure to moisture, heat, open flames
Incompatible Materials: Strong oxidizers like hydrogen peroxide, strong acids
Hazardous Decomposition Products: Sulfur oxides (SOx), nitrogen oxides (NOx), potentially carbon monoxide under fire or thermal stress
Routes of Exposure: Inhalation, skin, eyes, ingestion
Acute Toxicity: Practically non-toxic at typical usage levels (LD50 oral, rat: approximately 1890 mg/kg)
Skin Corrosion/Irritation: Mild irritation possible, more likely if skin is abraded or sensitive
Serious Eye Damage/Irritation: Possible short-term redness or irritation
Respiratory Sensitization: Chronic exposure to dust can irritate respiratory tract
Carcinogenicity: Not classed as carcinogenic by IARC, NTP, or OSHA
Mutagenicity: Not recognized as mutagenic
Reproductive Toxicity: No evidence for adverse reproductive effects in available studies
Chronic Effects: No reported long-term health hazards under normal conditions
Ecotoxicity: At moderate concentrations, not known to cause harm to aquatic organisms. In large, uncontrolled releases, can deplete oxygen due to microbial oxidation.
Persistence and Degradability: Readily biodegradable in water and soil
Bioaccumulative Potential: Low, does not bioaccumulate in fish or food chains
Mobility in Soil: High water solubility leads to ready migration through soil, but rapid degradation
Other Adverse Effects: None identified at typical use or accidental exposure levels
Waste Treatment Methods: Dispose through approved chemical waste disposal contractor
Product Disposal: Sweep up and place in sealed, labelled container. Small amounts can be dissolved in excess water, neutralized with dilute acid or base, then disposed of according to regional requirements.
Contaminated Packaging: Rinse containers thoroughly and recycle if possible. Spilled material and cleaning aids should follow local environmental protection guidance.
Sewage Disposal: Avoid introduction to municipal sewage or storm water systems unless downstream treatment is verified.
UN Number: Not regulated for transport
Proper Shipping Name: L-Cysteine
Transport Hazard Class: Not classified as hazardous
Packing Group: Not applicable
Marine Pollutant: Not a marine pollutant
Special Transport Precautions: Secure packaging to prevent damage. Keep dry during shipping to prevent caking or spoilage.
Safety, Health and Environmental Regulations: L-Cysteine is listed under relevant chemical inventories including TSCA (US), REACH (EU), DSL (Canada), AICS (Australia). No significant restrictions for workplace or environmental use in non-pharmaceutical contexts.
Labelling Requirements: General chemical safety labeling advised. Not subject to major hazard classification.
Workplace Limits: Observe nuisance dust standards for airborne particulate.
Other Regulations: Food and pharmaceutical use must comply with purity and additive requirements of the FDA, EFSA, and similar bodies worldwide. Local, state, and federal environmental regulations for chemical waste apply. No restrictions under US SARA, CERCLA, or California Prop 65.
West Ujimqin Banner, Xilingol League, Inner Mongolia, China
