Product Name: 2-Acetyl-5-Hydrothiophene
Chemical Formula: C6H6OS
CAS Number: 13679-85-1
Synonyms: 1-(5-Thienyl)ethanone, 5-Acetylthiophene
Recommended Uses: Flavor and fragrance manufacturing, chemical research, intermediate synthesis
Supplier Details: Commonly listed chemical distributors and lab supply companies such as Sigma-Aldrich and Fisher Scientific
Emergency Phone Number: Refer to CHEMTREC or local emergency response contacts
Address: Supplier-specific; usually available on shipment slips or company website.
GHS Classification: Flammable liquid Category 3, Acute toxicity Category 4 (oral), Skin and eye irritant Category 2
Signal Word: Warning
Hazard Statements: Flammable liquid and vapor, harmful if swallowed, causes skin and eye irritation
Precautionary Statements: Keep away from open flames and hot surfaces, use only in well-ventilated areas, wear protective equipment
Pictograms: Flame, exclamation mark
Routes of Exposure: Inhalation, ingestion, skin and eye contact
Target Organs: May affect central nervous system if inhaled in high concentrations, irritating to mucous membranes and skin
Symptoms: Dizziness, headache, nausea, eye and skin redness, coughing, sore throat.
Chemical Name: 2-Acetyl-5-Hydrothiophene
Synonyms: 5-Acetylthiophene
CAS Number: 13679-85-1
EC Number: 237-182-6
Weight Percent: ≥98%
Impurities: Typically trace organosulfur compounds, residual solvents, unknown at less than 2% concentration
Other Components: No known hazardous stabilizers or additives in pure form.
Inhalation: Move outside for fresh air immediately, loosen tight clothing, seek medical officer or doctor if symptoms develop or persist
Skin Contact: Remove contaminated clothing, wash skin thoroughly with soap and water for at least 15 minutes, trip to a medical provider if rash or burning appears
Eye Contact: Rinse opened eyelid under running water for at least 15 minutes, remove contact lenses if present, arrange an eye exam to check for irritation or injury
Ingestion: Rinse mouth, do not induce vomiting, head to the hospital quickly, bring original product label if possible
Symptoms to Watch: Shortness of breath, headache, eye burning, dizziness, or nausea
Notes for Medical Personnel: Symptomatic and supportive care, no known antidote
Special Guidance: Take care of your own protection—use gloves, avoid mouth-to-mouth rescue.
Suitable Extinguishing Media: Foam, dry chemical powder, carbon dioxide, water spray (do not use full force water jet to avoid spreading)
Specific Hazards: Vapors may form explosive mixture with air, dense smoke possible under incomplete burning
Hazardous Combustion Products: Carbon oxides, sulfur oxides, potentially irritating or toxic fumes
Advice for Firefighters: Put on self-contained breathing apparatus and chemical-resistant clothing, keep upwind, prevent runoff from firefighting entering drains
Additional Info: Cool closed containers near fire with water spray, remove them from area if possible without risk.
Explosion Risk: Closed containers could rupture if heavily heated by fire
Flash Point: Usually between 60-70°C; verify with batch certificate
Special Hazards Arising: Burning releases sharp, irritating smoke, particularly from sulfur decomposition.
Personal Precautions: Wear gloves, lab coat, chemical splash goggles, and respirator mask in strong vapor conditions
Environmental Precautions: Prevent from entering drains, sewers, groundwater, or open waterways
Methods for Clean-up: Absorb small spills with inert material like sand or vermiculite, shovel into labeled waste container, clean final residue with soap and water
Large Spills: Evacuate non-essential personnel, ventilate area, contain liquid with dikes or non-combustible material, notify local environmental authority
Decontamination Tools: Industrial absorbents, chemical-resistant scoops, sealable containers for chemical waste
Additional Measures: Rinse contaminated tools, prevent accidental contact or spread through shoes or rags.
Handling: Work in an area with chemical fume hood or strong ventilation, avoid direct skin or eye contact, keep away from ignition sources, no eating, drinking, or smoking in handling area
Storage Conditions: Store in tightly sealed, clearly labeled containers, cool and dry location, separate from oxidizers and strong acids or bases
Storage Temperature: Room temperature usually suffices, but under 30°C recommended for stability, avoid freezing
Incompatible Materials: Strong oxidizing agents, strong acids, and bases
Safe Storage Container: Amber glass bottle or compatible chemical-resistant plastic
Special Rules: Check regularly for leaks or deterioration, keep paperwork and MSDS nearby, train staff on proper storage and handling
Transfer Guidelines: Use grounded pumps in transfer, prevent static discharge, recap and seal drums securely.
Shelf Life: About 12 months in factory-sealed container; chemical will degrade faster under heat or exposure to air and light.
Workplace Exposure Limits: Not established; minimize exposure using best practice
Engineering Controls: Use chemical fume hood, good general room ventilation
Eye Protection: Safety goggles, face shield for large volumes
Skin Protection: Gloves made of nitrile or neoprene, full sleeve lab coat
Respiratory Protection: For heavy vapor or accidental release, a NIOSH-approved chemical respirator or half facepiece mask
Hand Protection: Change disposable gloves frequently, wash hands after use
Environmental Controls: Use containment mats, spill trays, fume extraction devices
Personal Hygiene: Remove contaminated clothing, shower if splashed, avoid touching face during handling.
Special Considerations: For sensitive individuals or those with respiratory disorders: avoid handling without additional protective equipment.
Appearance: Pale yellow to light brown liquid
Odor: Intense, buttery or cheese-like, sulfurous aroma reminiscent of cooked onions
Molecular Weight: 126.18 g/mol
Boiling Point: Near 200°C
Melting Point: Around -2°C
Vapor Pressure: Low at room temperature; check with supplier's data sheet
Solubility: Practically insoluble in water, soluble in organic solvents like ethanol, diethyl ether, and acetone
Density: Close to 1.16 g/cm³
pH Value: Not applicable (neutral organic liquid)
Flash Point: About 65°C (closed cup)
Evaporation Rate: Moderate (not as volatile as acetone or diethyl ether)
Autoignition Temp: Not well documented; often just above 200°C
Explosion Limits: No data provided, best to treat as if vapors are flammable near sources of ignition
Partition Coefficient: High logP, accumulates in fatty tissues more than water-based systems.
Chemical Stability: Stable under recommended handling, light and heat will speed decomposition
Incompatible Materials: Strong oxidizers like peroxides, concentrated acids (sulfuric, nitric), alkali metals
Hazardous Decomposition: Produces toxic fumes of sulfur oxides and carbon oxides if burned or decomposed
Conditions to Avoid: Open flames, sparks, heat above ambient, exposure to sunlight for longer periods
Polymerization: Not known to polymerize dangerously
Reaction with Metals: Avoid mixing with reactive metals (sodium, potassium)—risk of fire
Reaction with Acids/Bases: Can react with concentrated acids or bases surging vapor release or exothermic reaction
Signs of Instability: Discoloration, strange smells, pressure build-up in container.
Storage Longevity: Deteriorates faster outside of original container and at elevated temperature.
Acute Toxicity: Moderate; oral LD50 in rats estimated between 500-2,000 mg/kg
Skin Corrosion/Irritation: Can cause localized redness or blistering after prolonged exposure
Eye Damage/Irritation: Splash into the eyes causes burning, redness, tearing, possible conjunctivitis
Respiratory Sensitization: Strong vapor irritates nose, throat, headache, coughing above recommended airborne levels
Carcinogenicity: Not listed as carcinogenic by OSHA, NTP, IARC or EU
Reproductive/Developmental: No definitive data, precaution around pregnant persons recommended
Chronic Effects: Potential to worsen asthma/bronchitis with repeated exposure, especially if inhaled for several months
Mutagenicity: No conclusive data from animal or human studies
Additional Info: Not recognized as acutely toxic or fatal at low exposure, but repeated mishandling shows cumulative effects on mucous membranes.
Eco-Toxicity: Harmful to aquatic organisms in concentrated form, risk of bioaccumulation in water life
Persistence and Degradability: Organic; slowly degrades by microorganisms in soil and water but not readily biodegradable by all standards
Bioaccumulative Potential: Moderate to high; lipophilic (logP high), can build up in fish and fatty animal tissues
Mobility in Soil: Low water solubility but could permeate soil and contaminate groundwater if repeatedly spilled
Other Adverse Effects: Direct release into waterways exposes fish and amphibians to organosulfur toxicity
Precautions: Use containment systems, do not dispose into open drains or unprotected soil.
Waste Disposal: Treat leftover liquid and absorbent with hazardous waste collection; avoid landfill and regular trash
Disposal Containers: Use clearly marked, sealed, chemical-safe canisters or drums
Sewage Disposal: Not allowed; product persists in municipal sewage and risks environmental release
Local Regulations: Only licensed hazardous waste sites or incinerators with sulfur scrubbing should process
Special Guidance: Rinse all used containers three times with suitable solvent before proper disposal, document disposal process
Household Disposal: Not suitable, always consult local hazardous waste services.
Empty Container Caution: Rinsed containers could still release fumes; puncture or crush with care under an approved program.
UN Number: 1993 (for flammable liquids, n.o.s.)
Proper Shipping Name: Flammable liquid, organic, n.o.s. (2-Acetyl-5-Hydrothiophene)
Transport Hazard Class: 3 (flammable liquid)
Packing Group: III (moderate hazard)
Marine Pollutant: No specific marine pollutant classification, but environmental care still required
Placard Requirements: Flammable liquid, label Class 3 for ground/sea/air
Special Transportation Advice: Secure containers against leak, keep upright, avoid stacking, verify container integrity
Emergency Response Guide: ERG Code 128 for flammable liquids
Regional Notes: Some countries may require additional paperwork; consult current restricted substances lists before shipping.
Inventory Listings: Registered under TSCA (USA), REACH (Europe), DSL (Canada), AICS (Australia)
Classification: Meets hazardous material definitions under OSHA Hazard Communication Standard and CLP regulation in Europe
Label Elements: GHS/CLP pictograms required for supply and transport
Safety, Health, and Environmental Regulations: Observe workplace exposure and use-restriction rules; chemical-specific controls for storage and waste
SARA Title III: Not listed as an extremely hazardous substance
Transport Compliance: Follows DOT and IATA restrictions for flammable organic liquids
Workplace Posting: Post MSDS in open workplace areas, conduct annual training
RoHS and REACH: Not specifically restricted, but always check if application relates to food or consumer goods.
Local Regulatory Advice: Keep updated with new chemical safety bulletins; rules shift as new hazard data appears.
