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Product Name: L-Cysteine Base
Chemical Name: 2-Amino-3-mercaptopropanoic acid
Synonyms: Cysteine, L-2-Amino-3-mercaptopropanoic acid, L-β-Mercaptoalanine
CAS Number: 52-90-4
Molecular Formula: C3H7NO2S
Molecular Weight: 121.16 g/mol
Recommended Use: Laboratory research, pharmaceutical manufacturing, food industry as a nutritional supplement or dough conditioner
Supplier: Listed on shipment documents, chemical manufacturer, or authorized distributor contact details
Emergency Contact: Refer to the company’s emergency contact on the MSDS
GHS Classification: Eye Irritation Category 2A, Skin Irritation Category 2, Specific Target Organ Toxicity–Single Exposure Category 3
Signal Word: Warning
Hazard Statements: Causes skin and eye irritation, may cause respiratory irritation
Pictograms: Exclamation Mark
Precautionary Statements: Avoid breathing dust or vapors, wash hands thoroughly after handling, use only outdoors or in a well-ventilated area, wear protective gloves and eye protection
Potential Health Effects: Exposure can lead to skin redness, eye discomfort, coughing, or sneezing from dust; ingestion in large doses can cause gastrointestinal upset
Chemical: L-Cysteine
Concentration: Greater than 99% purity
Impurities: Less than 1% trace inorganic salts and water, as reported by lot testing
Component: No significant contaminants reported by major producers
General Advice: Move victim away from exposure zone, remove contaminated clothing, and seek immediate medical attention if symptoms develop
Inhalation: Remove to fresh air, keep at rest, seek medical guidance if irritation or symptoms persist
Ingestion: Rinse mouth with water, never induce vomiting unless told by a medical professional, seek care if feeling unwell
Skin Contact: Wash thoroughly with mild soap and water, remove contaminated clothing and launder before reuse
Eye Contact: Flush eyes with running water for at least 15 minutes, lifting lids occasionally; seek medical care if irritation, pain, or redness continues
Symptoms: Itchy or burning eyes, skin redness, cough, or mild stomach discomfort
Extinguishing Media: Dry chemical, carbon dioxide, foam, or water spray for larger fires
Unsuitable Media: Do not use high-pressure water jet directly
Hazardous Combustion Products: Carbon oxides, nitrogen oxides, and sulfur oxides produced on combustion
Firefighters’ Protection: Use self-contained breathing apparatus and full protective clothing
Special Hazards: Dust may generate combustible mixture with air, adding risk of dust explosions in closed unventilated spaces
Spill Control: Avoid generating dust, ventilate area, evacuate nonessential personnel
Personal Protection: Use gloves, chemical splash goggles, and dust mask if needed
Containment: Sweep or shovel up spills, place in suitable bags or containers for proper disposal
Cleaning: Wash area with water after material removal, prevent entry into drains or watercourses
Environmental Precautions: Prevent bulk releases into soil or water; notify authorities if significant quantities enter waterways
Handling: Use in well-ventilated area, avoid dust formation, ground containers when transferring to minimize static charge risk
Storage: Store in dry, cool, and well-ventilated place, away from incompatible materials like strong oxidizers, acids, and bases
Container Requirements: Keep containers tightly closed and labeled, protect from moisture, avoid direct sunlight
Hygiene Measures: Wash hands and face after use, do not eat, drink, or smoke in work area
Exposure Limits: No OSHA PEL; ACGIH TLV not established specifically for L-cysteine, but normal chemical hygiene practices apply
Engineering Controls: Use general or local exhaust ventilation, especially at points of dust generation
Personal Protective Equipment: Safety goggles, impermeable gloves (nitrile or latex), lab coat or apron as appropriate
Respiratory Protection: NIOSH-approved respirator if dust or aerosols are present above control thresholds, especially in bulk handling
Work Practices: Avoid inhaling powder, prevent dust accumulation on work surfaces, monitor air quality in large-scale handling
Appearance: White crystalline or powder material
Odor: Mild, slightly sulfurous
pH (1% solution): 4.8–5.2
Melting Point: 220°C (decomposes on melting)
Boiling Point: Not applicable (material decomposes prior to boiling)
Solubility in Water: Soluble (up to approx. 280 g/L at 25°C)
Vapor Pressure: Negligible under ambient conditions
Flash Point: Not flammable in normal use
Density: 1.68 g/cm³
Partition Coefficient: n-octanol/water: log Kow: estimated -2.49
Other Information: Stable as a dry powder; hydrolyzes slowly in solution, releasing sulfur compounds over time if exposed to air
Chemical Stability: Stable under recommended conditions, sensitive to light and air in solution, forming disulfide compounds
Reactivity: May react with strong oxidizers, acids, and alkalis releasing sulfur-containing gases
Hazardous Reactions: Exothermic reactions possible with strong oxidants and nitrites
Decomposition Products: Carbon dioxide, ammonia, hydrogen sulfide, nitrogen oxides, and sulfur oxides
Conditions to Avoid: High heat, direct sunlight, exposure to damp air, incompatible substances
Acute Toxicity: Oral LD50 (rat): approximately 1890 mg/kg; low hazard in small-scale exposure, but potentially harmful in overdose or chronic exposure
Routes of Exposure: Skin contact, eye contact, inhalation, ingestion
Symptoms: Mild skin or eye irritation, sore throat or coughing
Chronic Effects: Repeated or prolonged exposure could trigger allergic skin reactions in sensitive individuals
Carcinogenicity: Not listed by IARC, NTP, OSHA as a carcinogen
Mutagenicity: No evidence under recommended use; standard genotoxicity studies show negative results
Reproductive Effects: No known issues based on available animal data
Ecotoxicity: Material breaks down in natural environments, generally low aquatic and terrestrial toxicity at normal levels of release
Persistence and Degradability: Readily biodegradable; forms sulfate and other mineral products in soils and water
Bioaccumulative Potential: Very low, does not persist in food chain
Mobility in Soil: Moderate, dissolves easily in water and may migrate in the upper soil layers before degrading
Effects on Wastewater: High concentrations may lower biological oxygen demand temporarily, but material will break down
Unused Material: Send to licensed chemical disposal facility, avoid landfill or uncontrolled dumping
Contaminated Packaging: Rinse thoroughly, offer for recycling or disposal according to local regulations
Incineration: Permitted at a regulated site, recover energy if process allows
Special Precautions: Do not flush in bulk amounts to sewer or surface water
Regulatory Waste Codes: Consult local authorities or waste contractor for proper identification as waste is not classified as hazardous under common federal or EU codes unless contaminated
UN Number: Not regulated for ground, sea, or air transport as per ADR/RID, IMDG, IATA guidelines
Shipping Name: L-Cysteine, not dangerous goods
Packing Group: Not applicable
Hazard Class: Not regulated
Label Required: No specific transport hazard label required
Special Transport Notes: Keep containers tightly closed and protected from contaminants during shipment; observe basic hygiene during loading/unloading
TSCA (US): Listed
DSL/NDSL (Canada): Listed
REACH (EU): Registered substance
EC Number: 200-158-2
California Proposition 65: Not listed
WHMIS (Canada): Not classified
Labelling: GHS-compliant labelling in accordance with local jurisdiction required on shipments
Other Standards: Meets general workplace safety requirements for handling chemicals in labs, food, or pharmaceutical manufacturing; not classified as a major environmental hazard
