Material Safety Data Sheet: Sulfuryl Chloride (SO₂Cl₂)

Identification

Product Name: Sulfuryl Chloride
Chemical Formula: SO₂Cl₂
Other Names: Sulfuryl dichloride, Sulfuric dichloride, Sulfur oxychloride
CAS Number: 7791-25-5
Recommended Use: Chemical intermediate, chlorinating agent, laboratory reagent
Manufacturer Information: Address, telephone, emergency contact for manufacturer or supplier
Emergency Phone: Chemtrec (or applicable regional emergency hotline)

Hazard Identification

Classification: Acute Toxicity (oral, inhalation, dermal), Corrosive to metals, Skin corrosion/irritation, Eye damage/irritation, Specific target organ toxicity (STOT) single exposure
Label Elements: Corrosive, Toxic, Dangerous for the environment (GHS pictograms: skull and crossbones, exclamation mark, corrosion)
Signal Word: Danger
Hazard Statements: Toxic if inhaled, Toxic in contact with skin, Causes severe skin burns and eye damage, Causes serious eye damage, Causes respiratory irritation
Precautionary Statements: Avoid breathing vapors, ensure good ventilation, use PPE, wash thoroughly if exposed, store locked up, seek immediate medical attention if exposed
Health Hazards: Vapor highly irritating to respiratory system, may cause delayed lung injury, direct contact burns skin/eyes, ingestion damages GI tract
Environmental Hazards: Very toxic to aquatic life, avoid release to environment

Composition / Information on Ingredients

Chemical Name: Sulfuryl Chloride
Concentration: 99% or greater
Synonyms: See Identification section
CAS Number: 7791-25-5
Impurities Stabilizers: Typical stabilizer: minimal, check supplier data; small quantities of stabilizing agents may be added

First Aid Measures

Inhalation: Remove to fresh air, keep warm and at rest, immediate medical attention, artificial respiration if breathing stops
Skin Contact: Remove contaminated clothing, rinse skin with copious water for at least 15 minutes, medical evaluation required, do not use neutralizing agents
Eye Contact: Immediate and thorough water flush for 15 minutes, remove contact lenses, continue rinsing, urgent ophthalmological attention
Ingestion: Do not induce vomiting, rinse mouth (only if conscious), never give anything by mouth to an unconscious person, seek immediate medical help
Most Important Symptoms: Severe irritation, coughing, shortness of breath, chest pain, blistering, burns, risk of delayed pulmonary edema
Advice for Doctor: Symptomatic and supportive treatment, monitor for lung injury, treat as corrosive poisoning

Fire-Fighting Measures

Suitable Extinguishing Media: Dry powder, CO₂, foam; avoid water directly on chemical
Unsuitable Extinguishing Media: Direct water jets (violent hydrolysis, toxic vapors)
Hazardous Combustion Products: Releases toxic chlorine, sulfur dioxide, hydrogen chloride gases
Specific Hazards Arising from Chemical: Reacts with moisture to produce heat and toxic fumes, may cause violent reactions, containers may rupture
Protective Equipment for Firefighters: Full protective clothing, positive-pressure SCBA, chemically resistant gloves and boots
Fire/Explosion Hazards: Contact with water or moist air generates heat and corrosive gas
Advice: Cool containers from a distance, avoid runoff into water bodies, evacuate area downwind

Accidental Release Measures

Personal Precautions: Evacuate unprotected persons, ventilate area, full PPE including respirator, avoid vapor exposure
Environmental Precautions: Prevent spillage from reaching drains, surface water, or soil; alert authorities if contamination risk exists
Cleanup Methods: Absorb spill on dry, inert absorbent (vermiculite, dry sand), neutralize cautiously with sodium bicarbonate solution, collect in sealed barrels for disposal, ventilate area thoroughly; avoid water contact
Special Precautions: Prepare for delayed toxic release, ensure all involved staff understand chemical hazards

Handling and Storage

Handling: Use only in properly ventilated fume hood or enclosed system, minimize vapor exposure, never open containers near water, avoid skin contact, inspect containers for leaks before use, train staff in emergency procedures
Storage: Store in tightly closed containers of compatible material (glass, certain plastics; avoid metals), cool dry place, segregate from water, moist air, acids, bases, reducing agents
Incompatible Materials: Water, alcohols, amines, bases, reducing substances, metals, strong oxidizers
Storage Conditions: Clearly label containers, restricted access storage, secondary containment

Exposure Controls and Personal Protection

Exposure Limits: ACGIH TLV: 1 ppm (as SO₂Cl₂), OSHA PEL: Not established, employer may need to set lower internal exposure limits
Engineering Controls: Local exhaust ventilation, explosion-proof fume hood, eye wash and safety shower accessible
Personal Protective Equipment: Chemical-resistant gloves (butyl rubber, Viton), fully sealed goggles, face shield, acid-resistant apron, full coveralls, respiratory protection (organic vapor/acid gas cartridge or supplied-air, depending on amount used and ventilation)
Hygiene Practices: Wash hands thoroughly after handling, remove contaminated clothing, launder before reuse, avoid eating or drinking near chemical

Physical and Chemical Properties

Appearance: Colorless to pale yellow, fuming liquid
Odor: Sharp, suffocating, chlorine-like odor
Odor Threshold: Very low, strong warning properties
Melting Point: -54 °C
Boiling Point: 69 °C
Flash Point: Not flammable (but reacts violently with water)
Vapor Pressure: 84 mmHg at 20 °C
Solubility: Decomposes in water, exothermic, formation of HCl and SO₂
Density: 1.67 g/cm³ at 20 °C
Evaporation Rate: Rapid
Vapor Density: 4.6 (air = 1)
Partition Coefficient (Log Kow): 1.3 (estimated)
Other Data: Volatile; causes white fumes in humid air

Stability and Reactivity

Chemical Stability: Stable in dry, well-sealed containers, rapidly reacts with water
Conditions to Avoid: Moisture, elevated temperatures, exposure to light
Incompatible Materials: Water, bases, alcohols, reducing agents, metals
Hazardous Reactions: Contact with water liberates SO₂ and HCl; may ignite combustibles
Decomposition Products: Sulfur dioxide, hydrogen chloride, chlorine gas
Polymerization: Will not occur

Toxicological Information

Routes of Exposure: Inhalation, skin and eye contact, ingestion
Acute Effects: Highly toxic by all routes, causes severe irritation and burns to skin, eyes, mucous membranes. Inhalation may result in delayed pulmonary edema or fatality
Chronic Effects: Prolonged exposure may cause persistent respiratory tract damage, chronic bronchitis
LD₅₀ (oral, rat): 750 mg/kg
LD₅₀ (dermal, rabbit): 2000 mg/kg
LC₅₀ (inhalation, rat, 4h): Approximately 10-100 ppm (wide variability depending on conditions)
Sensitization: Not known to cause allergic sensitization
Other Health Effects: May cause chemical pneumonitis, systemic toxicity from absorption through skin

Ecological Information

Ecotoxicity: Toxic to aquatic organisms due to low pH and formation of hydrochloric acid and sulfur dioxide
Persistence and Degradability: Rapidly hydrolyzed in moist environments; not persistent in air, soil, or water
Biodegradability: Not relevant, breaks down abiotically before biodegradation can occur
Bioaccumulative Potential: Not expected due to rapid chemical breakdown
Mobility in Soil: Moves with water, but hydrolyzes rapidly
Other Adverse Effects: Aerosol releases pose acute hazard to aquatic life, careful spill and handling practices needed

Disposal Considerations

Waste Treatment Methods: Must be neutralized prior to disposal; small amounts react with dilute sodium bicarbonate solution under controlled conditions
Disposal of Containers: Rinse thoroughly with neutralizing solution before disposal following local hazardous waste regulations, do not puncture or incinerate unwashed containers
Special Precautions: Never discharge to sewer or surface water, always consult local and national regulations, coordinate with licensed chemical waste contractor

Transport Information

UN Number: UN 1834
UN Proper Shipping Name: Sulfuryl chloride
Hazard Class: 6.1 (Toxic substances), Subsidiary risk 8 (Corrosive substances)
Packing Group: I (Highest danger level)
Labeling: Toxic, Corrosive
Marine Pollutant: Yes
Transport Precautions: Secure packaging, upright positions, secondary containment, emergency response information provided, avoid moisture
Transport Regulations: Comply with local, national, and international transport rules (IMDG, IATA, ADR, US DOT)

Regulatory Information

U.S. Regulations: Listed on TSCA inventory, subject to SARA Title III Sections 302 & 313, CERCLA reportable quantity 5000 lb
EU Regulations: Classified under CLP (Regulation (EC) 1272/2008), Seveso Directive, REACH registration required
Canada: Listed on DSL/NDSL, WHMIS Class D-1A, E
International: Listed by most chemical inventories, subject to strict local controls on use and discharge
Labeling Guide: Skull and crossbones, corrosion hazard pictograms, “Danger: May Cause Severe Burns or Death” mandatory under GHS/OSHA
Other Restrictions: Restricted in many countries to certain industrial sectors, chemical intermediates