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Chemical Name: Diethyl Phosphite
Common Synonyms: Phosphorous acid, diethyl ester
Chemical Formula: (C2H5O)2P(O)H
CAS Number: 762-04-9
Appearance: Clear, colorless to pale yellow liquid with a characteristic odor
Uses: Intermediate in the production of flame retardants, stabilizers, pesticides, and pharmaceuticals
Hazard Classification: Flammable liquid, harmful if inhaled or ingested, corrosive to skin and eyes
Signal Word: Danger
Hazard Statements: Causes severe skin burns and eye damage, may cause respiratory irritation, harmful to aquatic life
Pictogram: Corrosive, exclamation mark, environment
Potential Health Effects: Exposure can result in burns, respiratory problems, eye damage, and digestive tract irritation. Splashes in eyes often lead to immediate pain and long-lasting injury, while skin contact may cause chemical burns if not quickly washed off.
Main Component: Diethyl Phosphite
Purity: Typically above 95%
Other Substances: Trace impurities from production, usually less than 2%
Inhalation: Move the affected person to fresh air, keep at rest, and seek immediate medical attention. If breathing becomes difficult, oxygen should be administered by trained personnel.
Skin Contact: Remove contaminated clothing and rinse skin immediately with plenty of running water. Even small splashes call for prompt washing; burns may not be visible at first.
Eye Contact: Rinse with water for at least 15 minutes and get medical help right away; even minor splashes can permanently damage the eyes.
Ingestion: Do not induce vomiting; rinse mouth with water and consult a doctor as soon as possible.
Suitable Extinguishing Media: Carbon dioxide, dry chemical, foam. Water spray can cool containers but should not be used directly on the substance due to the risk of spreading.
Special Hazards: Vapors may form explosive mixtures with air, combustion can produce irritating and toxic fumes including phosphorus oxides.
Protective Equipment: Firefighters need chemical-resistant clothing and self-contained breathing gear.
Special Procedures: Containers exposed to fire or heat can rupture; evacuate area if possible, keep cool with sprayed water if safe to do.
Personal Protection: Wear gloves, goggles, protective clothing, and respiratory protection.
Spill Response: Contain spill to prevent spread, absorb with inert material such as sand, and place in closed container for proper disposal.
Environmental Precautions: Prevent runoff to drains, surface and groundwater; toxicity to aquatic organisms remains a concern.
Cleanup Methods: Ventilate area; use non-sparking equipment. Wash residue with water and ensure proper ventilation during and after cleanup.
Safe Handling: Handle in well-ventilated areas; always wear protective gear including gloves, goggles, and long-sleeved clothing. Avoid breathing vapors, avoid contact with skin and eyes, and keep away from ignition sources.
Storage Requirements: Keep in tightly closed containers, stored in cool, dry spaces away from direct sunlight, oxidizers, bases, and strong acids. Maintain containers upright and labeled securely. Dedicated chemical storerooms help manage risks.
Engineering Controls: Use fume hoods, local exhaust, and well-designed ventilation to reduce vapor levels. Automated systems help prevent unnecessary handling and exposure.
Eye Protection: Chemical splash goggles or face shields
Skin Protection: Impermeable gloves (nitrile, neoprene), long-sleeved laboratory coats or coveralls
Respiratory Protection: NIOSH-approved organic vapor respirators for high vapor concentrations. Respiratory gear proves especially vital during spills or cleaning work.
Hygiene Measures: Wash hands thoroughly after handling and before eating, drinking, or smoking.
Physical State: Liquid
Color: Clear to pale yellow
Odor: Pungent, acidic smell
Boiling Point: Around 183°C
Melting Point: Below room temperature
Flash Point: 74°C (closed cup)
Solubility: Moderately soluble in water, easily mixes with organic solvents
Density: Approximately 1.07 g/cm³ at 20°C
Vapor Pressure: Low at room temperature
Other notable features: Forms hazardous decomposition products such as phosphorus oxides when overheated.
Chemical Stability: Generally stable in sealed containers stored away from moisture, heat, and light.
Conditions to Avoid: Open flames, spark sources, excessive heat, and contact with strong bases, acids, or oxidizers.
Hazardous Decomposition Products: Thermal breakdown can create phosphorus oxides and other irritating or toxic gases.
Polymerization: Not expected to polymerize in normal industrial or laboratory environments.
Acute Toxicity: Inhaling vapors can cause headaches, nausea, coughing, and respiratory trouble. Direct exposure damages skin and mucous membranes quickly.
Skin Corrosion/Irritation: Causes burns and blistering on contact.
Serious Eye Damage/Irritation: Strong risk of severe injury, vision loss, and pain.
Chronic Effects: Repeated exposure may lead to sensitization, recurring dermatitis, and potentially worsen asthma or bronchitis.
Ingestion Hazards: Swallowing leads to stomach pain, nausea, diarrhea, and, in heavier doses, severe internal burns or systemic toxicity.
Aquatic Toxicity: Poses a risk to water organisms, particularly in confined or slow-moving water systems. Large releases threaten fish, amphibians, and invertebrates.
Persistence and Degradability: Slowly breaks down in soil and water, but the acidic and reactive nature can disrupt microbial activity and plant growth near spills.
Bioaccumulation: Not known to accumulate significantly in animal tissues, but continuous exposure can stress local ecosystems.
Waste Handling: Collect residues and unused liquid in properly labeled chemical waste containers; do not pour down drains or sewers.
Disposal Methods: Use certified hazardous waste contractors. Incineration at approved facilities works best.
Environmental Note: Even small wastage can cause persistent environmental damage. All disposal steps should be recorded to demonstrate responsible management.
General Shipping Conditions: Classified as a hazardous material; containers must be tightly closed, labeled with hazard symbols, and cushioned against shock and leaks.
Recommended Packaging: Use corrosion-proof and leak-proof drums, well secured during transport.
Loading Procedures: Only properly trained personnel should handle and move containers, especially in bulk.
International Standards: Covered by strict regulations for hazardous and corrosive chemicals in the workplace, lab, or factory. Safety practices, labeling, and emergency planning are all required.
Local Laws: Many states or countries require inventory and reporting of stored quantities above set limits. Waste generators face additional reporting and inspection rules.
