Material Safety Data Sheet (MSDS) – Liquid Argon

Identification

Product Name: Liquid Argon
Chemical Formula: Ar
CAS Number: 7440-37-1
Recommended Use: Cryogenic refrigerant, shield gas in welding, laboratory applications, manufacturing
Supplier Details: Manufacturer’s name, address, and emergency contact phone number
Synonyms: Cryogenic argon, refrigerated argon liquid
UN Number: UN1951

Hazard Identification

Classification: Compressed gas, liquefied gas (GHS Compliant)
Label Elements: Gas under pressure, may explode if heated
Main Hazards: Causes rapid suffocation by displacing oxygen, risk of cold burns or frostbite on contact with skin, rapid vaporization poses explosion risk from pressure buildup
Hazard Symbols: GHS04 (gas cylinder), GHS07 (exclamation mark for low-temperature hazard)
Precautionary Statements: Store locked up, avoid breathing gas, use only outdoors or in well-ventilated area, keep container tightly closed

Composition / Information on Ingredients

Chemical Name: Argon
Concentration: 99.99% and above
Impurities: Trace levels of oxygen, nitrogen in ultra-high purity grades
CAS Number: 7440-37-1
Molecular Weight: 39.95

First Aid Measures

Inhalation: Remove person to fresh air immediately, give oxygen if breathing is difficult, call for medical help if symptoms persist, artificial respiration if breathing has stopped
Skin Contact: Remove contaminated clothing, immediately flush area with warm (not hot) water, seek medical attention for frostbite
Eye Contact: Rinse eyes gently with water for at least 15 minutes, do not rub, obtain medical evaluation right away
Ingestion: Not considered a likely route of exposure due to boiling point; treat as for other cryogenic exposures
Note to Physician: Treat symptoms, asphyxia from oxygen displacement is primary risk, monitor for hypoxia and frostbite injury

Fire-Fighting Measures

Suitable Extinguishing Media: Argon itself is not flammable and does not support combustion; use media suitable for surrounding fire
Special Hazards: Heat or fire causes rapid pressure buildup and possible rupture of containers; argon displaces oxygen and may cause asphyxiation
Protective Equipment: Self-contained breathing apparatus, full protective clothing
Advice for Firefighters: Cool containers with water spray to prevent pressure buildup, evacuate personnel from area, approach from upwind

Accidental Release Measures

Personal Precautions: Wear insulated gloves and eye protection, ensure adequate ventilation, evacuate unnecessarily exposed personnel
Environmental Precautions: Prevent large volumes from entering confined spaces, argon is not toxic to the environment but displaces oxygen
Methods for Clean Up: Ventilate area, stop leak if it can be done safely, allow gas to dissipate naturally without direct intervention
Emergency Procedures: Remove ignition sources, restrict access until area is safe, use gas detection system to verify oxygen levels

Handling and Storage

Safe Handling: Avoid skin and eye contact with liquid or cold vapor, do not inhale gas, use only in well-ventilated or outdoor areas, secure containers upright, transport with valve protection in place
Storage Conditions: Store in cryogenic liquid cylinders or Dewar flasks, keep away from heat and direct sunlight, maintain storage temperature below boiling point (-186°C), never seal containers completely
Technical Measures: Provide proper pressure relief devices on storage tanks, use only materials compatible with cryogenic temperatures, prevent ice accumulation around pressure relief valves, segregate from oxygen-consuming chemicals

Exposure Controls and Personal Protection

Exposure Limits: No OSHA PEL or ACGIH TLV established, but oxygen levels must remain above 19.5% in workplace
Engineering Controls: Adequate general and local exhaust ventilation required, oxygen monitoring in enclosed workspaces
Personal Protective Equipment: Insulated cryogenic gloves, safety goggles or face shield, lab coat or protective jacket, closed-toe footwear
Special Precautions: Never handle with wet gloves, use oxygen monitors in storage and use areas, provide training on argon hazards

Physical and Chemical Properties

Appearance: Colorless, odorless liquid and vapor
Odor: None
Melting Point: -189.3°C
Boiling Point: -185.9°C
Vapor Pressure: 1 atm at -185.9°C
Density: 1.4 kg/L (liquid at boiling point)
Solubility: Slightly soluble in water
Critical Temperature: -122°C
Critical Pressure: 48 atm
Other Information: Gas is much heavier than air, tends to collect in low-lying areas

Stability and Reactivity

Chemical Stability: Stable under normal conditions, inert gas
Conditions to Avoid: Contact with incompatible materials (magnesium, lithium, titanium at high temps), extreme heat or flame, enclosed spaces without ventilation
Hazardous Decomposition Products: None
Reactivity: Unreactive under most conditions, may form explosive mixtures with certain metals at elevated temperatures

Toxicological Information

Acute Effects: Inhalation causes asphyxiation by replacing oxygen, symptoms include dizziness, headache, unconsciousness, death
Chronic Effects: No evidence of long-term health effects in humans
Routes of Exposure: Inhalation (primary), skin contact (frostbite hazard), eye contact (cryogenic burns)
Delayed/Immediate Effects: Rapid onset of symptoms with oxygen displacement, immediate frostbite possible with skin contact
Carcinogenicity: Not classified as carcinogenic by IARC, NTP, OSHA

Ecological Information

Ecotoxicity: Does not present environmental toxicity at normal concentrations, does not bioaccumulate or persist in biological systems
Persistence and Degradability: Not applicable, product is a noble gas and dissipates into atmosphere
Bioaccumulation Potential: None
Mobility in Soil: Free gas dissipates, no expected effect on ground or water
Other Adverse Effects: No known indirect environmental hazards

Disposal Considerations

Waste Disposal Methods: Allow unused argon to vent slowly and safely into outdoor atmosphere, avoid release in confined or low-lying areas, comply with local, state, and federal regulations
Container Disposal: Return empty cylinders to supplier, do not attempt to refill or alter cylinder markings and labels, relieve remaining pressure in a safe location before removal

Transport Information

UN Number: UN1951
Proper Shipping Name: Argon, refrigerated liquid
Transport Hazard Class: 2.2 (Non-flammable, non-toxic gas)
Packing Group: Not applicable
Special Precautions for Transport: Use shipping containers designed for cryogenic liquids, secure during transit, do not ship with incompatible materials, ensure all labels and markings remain intact
Regulatory References: U.S. DOT 49 CFR, ADR/RID, IATA, IMDG codes

Regulatory Information

OSHA Hazard Communication: Classified as hazardous due to asphyxiation and cold burn risks
TSCA Status: Listed
SARA Title III: Not reportable under SARA 302, 304, 311/312, 313
California Proposition 65: Not listed
WHMIS Classification (Canada): Class A (Compressed Gas)
Other International Regulations: Subject to workplace chemical safety laws in EU, Australia, Japan, and other jurisdictions
Label Requirements: Cylinder must carry appropriate hazard symbols and precautionary phrases as per GHS/OSHA standards
Restrictions: For use by trained personnel only, not for consumer use or for inhalation