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Chemical Name: O,O,O',O'-Tetraethyl S,S'-Methylenebis(Dithiophosphate)
Common Name: Methylenebis(dithiophosphate), tetraethyl derivative
CAS Number: 15521-67-4
Recommended Use: Lubricant additive, anti-wear agent, corrosion inhibitor
Restrictions: Not intended for food or pharmaceutical applications
Manufacturer: Industrial chemical supplier
Contact Information: Safety department phone and emergency line listed on package
Emergency Overview: Yellow to amber liquid with strong, sulfide-like odor; avoid inhalation and skin contact
Synonyms: Tetraethyl methylene bisdithiophosphate, phosphorodithioic acid, methylene bis
GHS Classification: Acute Toxicity - Oral (Category 4), Skin Irritation (Category 2), Eye Irritation (Category 2A), Chronic Aquatic Toxicity (Category 2)
Signal Word: Warning
Hazard Statements: Harmful if swallowed, causes skin and eye irritation, toxic to aquatic life with long lasting effects
Symbol: Exclamation mark, environment
Precautionary Statements: Avoid breathing vapors, wear protective gloves/eye protection, wash hands after handling, avoid release to environment
Routes of Exposure: Inhalation, ingestion, skin and eye contact
Symptoms: Skin redness, eye watering, abdominal pain, nausea, headaches after high exposure
Potential Environmental Effects: Hazardous to fish and aquatic invertebrates
Chronic Effects: Prolonged exposure may lead to organ damage, especially liver and kidneys
Main Ingredient: O,O,O',O'-Tetraethyl S,S'-Methylenebis(Dithiophosphate) (CAS 15521-67-4) 85-95%
Impurities: Triethyl phosphate (CAS 78-40-0) <1%, minor organic sulfides and phosphates <2%
Additives: None reported
Stabilizers: No added stabilizers
Solvents: Trace hydrocarbon solvent residues possible depending on manufacturing process
Physical State: Liquid
Purity Grade: Technical grade
Inhalation: Move person to fresh air, support breathing, seek medical help if symptoms develop or persist
Skin Contact: Remove contaminated clothing, wash skin thoroughly with water and mild soap, consult physician if irritation remains
Eye Contact: Rinse eyes gently under running water for at least 15 minutes, do not rub eyes, seek medical evaluation if stinging or redness continues
Ingestion: Rinse mouth, never induce vomiting, obtain medical attention immediately
Signs To Watch: Difficulty breathing, excessive irritation, dizziness
Special Notes: Show physician product label or this MSDS
Extinguishing Media: Use foam, dry chemical powder, carbon dioxide; do not use water jets as they may cause spattering
Flammable Properties: Product is combustible; fumes contain sulfur oxides and phosphorous compounds
Hazardous Combustion Products: Sulfur dioxide, phosphoric acid, ethyl alcohol, carbon monoxide, carbon dioxide
Firefighter Protection: Wear self-contained breathing apparatus, chemical-resistant suit
Explosion Risk: Decomposition under fire produces toxic and corrosive gases
Special Instructions: Dike runoff to prevent entry into sewers or water sources
Personal Precautions: Evacuate area, ventilate space, avoid skin/eye contact, wear protective gear (gloves, goggles, apron)
Environmental Precautions: Stop leak if safe, prevent entry to waterways/drains, inform environmental authorities in case of large spill
Cleanup Methods: Absorb with inert material (sand, earth), transfer to labeled waste container, wash area with detergent and water
Disposal Of Cleanup Materials: Dispose in accordance with local, national regulations
Secondary Danger: Risk of slipping due to liquid remains
Decontamination: Rinse tools and equipment well after cleanup
Worker Notes: Use spark-proof tools if vapor present
Handling Precautions: Work in well-ventilated areas, avoid inhaling fumes, prevent contact with skin or eyes
Storage Conditions: Store in original tightly closed container, cool dry shaded area, away from heat, sparks, open flames, strong oxidizing agents
Packaging Materials: Use polyethylene-lined drums, steel containers with corrosion resistance coating
Hygiene: Wash hands and face thoroughly after use, no eating, smoking or drinking during handling
Storage Temperature: Keep temperature between 5°C and 30°C to prevent product breakdown
Storage Life: Two years under recommended conditions
Transfer Methods: Mechanical pumping with fittings resistant to corrosion by organophosphates
Engineering Controls: Provide local exhaust ventilation, use fume hoods or extraction fans
Occupational Exposure Limits: No specific national OEL; ACGIH recommends minimizing exposure as much as possible
Respiratory Protection: Wear NIOSH-approved organic vapor respirator if ventilation is inadequate
Skin Protection: Wear chemical-resistant gloves (nitrile, neoprene), long sleeves, impermeable boots
Eye/Face Protection: Use chemical splash goggles and face shield
Other Protective Equipment: Chemical apron/coveralls, eye wash station and safety shower in immediate work area
Monitoring: Air monitoring recommended if handled above room temperature or in enclosed areas; biological monitoring for breakdown products may be warranted
Appearance: Yellow to amber transparent liquid
Odor: Slightly pungent, sulfurous
pH: 4-6
Melting Point/Freezing Point: Below -20°C
Boiling Point: >295°C at 760 mm Hg
Flash Point: 165°C (closed cup)
Evaporation Rate: Very slow at ambient conditions
Flammability: Combustible, not highly flammable
Explosive Limits: No data available
Vapor Pressure: <0.01 mm Hg at 20°C
Vapor Density: Heavier than air
Relative Density: 1.18-1.22 g/cm³
Solubility in Water: Negligible
Partition Coefficient (n-octanol/water): Approx. 3 (estimated)
Auto-ignition Temperature: >350°C
Decomposition Temperature: >200°C
Viscosity: 80-120 mPa.s at 25°C
Chemical Stability: Stable under recommended storage conditions
Reactivity: Reacts with strong oxidizing acids and alkalis
Incompatible Materials: Strong oxidizers, nitric acid, peroxides, bases
Hazardous Polymerization: Will not polymerize
Decomposition Products: Sulfur oxides, phosphorous oxides, ethanol upon burning or prolonged exposure to high temperatures
Conditions to Avoid: Prolonged exposure to high temperatures, sunlight, humidity, open flames
Special Warnings: Avoid contact with acids/bases which can cause violent reaction
Acute Toxicity: Oral LD50 (rat) 550 mg/kg; Dermal LD50 (rabbit) approx 1000 mg/kg
Inhalation: May irritate respiratory tract if aerosolized
Skin Corrosion/Irritation: Causes moderate irritation, repeated exposure may result in dermatitis
Eye Damage/Irritation: Causes significant irritation and transient damage
Respiratory Sensitization: Not classified as a sensitizer
Carcinogenicity: Not listed by NTP, IARC, OSHA
Mutagenicity: No data suggests genetic risk
Reproductive Toxicity: No evidence in tested animals
Chronic Effects: Prolonged/repeated exposure may affect liver/kidneys; monitor for organ-specific symptoms
Other Information: Breakdown products (thioacids, ethanol) have documented low to moderate toxicity on repeated exposure
Ecotoxicity: LC50 (fish, 96 hr): 0.7 mg/L, EC50 (daphnia): 1.5 mg/L
Persistence and Degradability: Slowly biodegradable, most break down within several weeks by hydrolysis and sunlight
Bioaccumulation Potential: Moderate bioaccumulation possible due to lipid solubility
Mobility in Soil: Low mobility; strongly adsorbs to soil particles
Aquatic Risk: Product is highly toxic to aquatic invertebrates and fish
Terrestrial Risk: Can harm soil microorganisms at high concentrations
Other Hazards: Avoid release to environment, accumulates in sediment
Waste Disposal Methods: Treat as hazardous waste according to local, state, federal regulations
Incineration: Suitable only in approved facilities with post-combustion acid scrubbing
Landfill Disposal: Acceptable only at approved sites with appropriate containment
Container Disposal: Remove product residues, triple-rinse container, puncture and dispose of as hazardous waste
Do Not: Discharge to septic systems, open water, or general landfill
Preferred Disposal: High-temperature incineration with residue capture and treatment
Reuse/Recycle: Do not reuse containers or recycle product
Regulatory Compliance: Follow EPA and local authority regulations for organophosphate disposal
UN Number: UN 3077
UN Proper Shipping Name: Environmentally hazardous substance, liquid, n.o.s. (contains tetraethyl bisdithiophosphate)
Transport Hazard Class: 9 (Miscellaneous)
Packing Group: III
Environmental Hazards: Marine pollutant
Special Precautions: Keep upright, stow away from food and animal feed
Transport Label: Environmentally hazardous substance, class 9 signage
Emergency Response: Refer to Emergency Response Guidebook for detailed response actions in transport accidents
US TSCA Inventory: Listed
OSHA Hazard Communication: This product is considered hazardous according to OSHA regulations
SARA Title III (Sections 311/312): Immediate (acute) health hazard, delayed (chronic) health hazard
SARA Title III (Section 313): Not subject to SARA 313 reporting
CERCLA: Not assigned a reportable quantity
RCRA: Subject to hazardous waste requirements if discarded
Canada WHMIS Classification: D2B - Toxic Material Causing Other Toxic Effects
EU Classification: Harmful (Xn), Dangerous for the Environment (N)
Labeling Compliance: Follow GHS/CLP labeling for signal word, pictograms, hazard and precautionary statements
