Product Name: Phosphorous Acid
Synonyms: Phosphonic Acid, Orthophosphorous Acid
Chemical Formula: H3PO3
Molecular Weight: 82.00 g/mol
CAS Number: 10294-56-1
Recommended Use: Used in chemical synthesis, water treatment, and as a reducing agent
Manufacturer: Refer to packaging or shipping documentation for supplier contact information
Emergency Contact: Refer to national poison control and local emergency response numbers
Product Code: Refer to product label and invoice
Preparation Date: Confirm with product originator
GHS Classification: Acute Toxicity Oral Category 4, Skin Corrosive Category 1B, Eye Damage Category 1
Signal Word: Danger
Hazard Statements: Harmful if swallowed, causes severe skin burns and eye damage
Precautionary Statements: Do not eat, drink, or smoke when using this product; wash hands thoroughly after handling; wear protective gloves, protective clothing, and eye/face protection; in case of inadequate ventilation, wear respiratory protection
Physical Hazards: Corrosive liquid and vapor
Health Hazards: Severe irritation and burns to skin, mucous membranes, respiratory tract; may be harmful if inhaled, ingested or in contact with eyes
Environmental Hazards: May be harmful to aquatic life if released in quantity
Chemical Name: Phosphorous Acid
Concentration: Typically above 99% pure unless diluted for commercial use
Impurities: Possible trace amounts of phosphoric acid and other phosphorus oxoacids based on production
Chemical Family: Inorganic acid
Ingredient Formula: H3PO3
EINECS Number: 233-663-1
Inhalation: Move victim to fresh air; call medical personnel; provide oxygen if available and breathing is difficult
Skin Contact: Immediately remove contaminated clothing; rinse skin with copious amounts of water; wash affected area with soap and water; seek medical attention for burns
Eye Contact: Flush eyes continuously with water for at least 15 minutes; hold eyelids open and remove contact lenses if possible; get immediate medical evaluation
Ingestion: Rinse mouth with water; do not induce vomiting; seek immediate medical help; never give anything by mouth to someone who is unconscious or convulsing
Important Symptoms: Severe burns, pain or irritation, coughing, shortness of breath, visual disturbances
Note to Physician: Treat symptomatically for chemical burns and monitor for delayed pulmonary effects if vapor has been inhaled
Suitable Extinguishing Media: Use water spray, dry chemical, CO2, or foam; avoid direct water jets which may spread spilled material
Specific Hazards: Acidic and corrosive nature makes it react with some metals producing flammable hydrogen gas; may decompose at high temperatures yielding toxic phosphorous oxides
Protective Equipment: Firefighters should wear self-contained breathing apparatus and chemical protective clothing to prevent skin and eye exposure
Advice for Firefighters: Approach from upwind, cool exposed containers and protect waterways from runoff; ensure ventilation in enclosed fire zones
Personal Precautions: Evacuate unnecessary personnel from area; ventilate affected space; wear chemical splash goggles, acid-resistant gloves, boots, and an apron
Environmental Precautions: Prevent further leakage or spillage if possible; do not let product enter drains, surface or groundwater
Cleanup Methods: Absorb with inert material such as sand or vermiculite; use non-sparking tools to collect spillage; place in suitable containers for disposal; neutralize residue with sodium bicarbonate or soda ash, then rinse with copious amounts of water
Decontamination Procedures: Wash affected area and contaminated equipment thoroughly with water after cleanup; ventilate area well before returning to service
Precautions for Safe Handling: Avoid breathing vapors or contact with skin and eyes; use only in a well-ventilated area; keep away from incompatible materials including strong oxidizers, bases and metals; avoid storing near food and animal feed
Storage Conditions: Keep container tightly closed in a dry, cool, well-ventilated place; store in original container; segregate from reactive and combustible materials; prevent container from freezing and direct sunlight
Storage Incompatibilities: Avoid storage with alkalis, oxidizing agents, and metals such as steel and aluminum that may react to release gases
Special Containment: Secondary containment methods recommended to prevent leaks and environmental discharge
Exposure Limits: No established OSHA, ACGIH, or NIOSH exposure limits; follow good workplace hygiene and safety standards
Engineering Controls: Provide local exhaust ventilation or process enclosure; use corrosion-resistant equipment and piping
Personal Protective Equipment: Wear chemical goggles or face shield, acid-resistant gloves, protective apron and long sleeves; ensure emergency eye-wash stations and safety showers are accessible
Respiratory Protection: Use appropriate NIOSH/MSHA-approved air-purifying respirators fitted with acid gas cartridges if ventilation is inadequate
Hygiene Measures: Wash hands and face before breaks, at end of work shift, and before eating, drinking, or smoking
Appearance: White crystalline solid or clear colorless solution
Odor: Slight, pungent
Odor Threshold: Not established
pH: Strongly acidic (about 1–1.5 for a 1M solution)
Melting Point: 73.6°C (solid)
Boiling Point: Decomposes rather than boils
Decomposition Temperature: Starts above melting point, yields phosphine and other oxides
Solubility: Completely soluble in water
Density: About 1.651 g/cm³ (solid)
Vapor Pressure: Not significant at ambient temperature
Viscosity: Not relevant for solid; aqueous solutions may have slightly increased viscosity
Flash Point: Not flammable
Partition Coefficient: Not applicable
Evaporation Rate: Negligible for solid form
Chemical Stability: Stable at standard temperature and pressure in closed containers; solutions may absorb moisture and degrade over time
Reactivity: Strong acid, reacts with bases and certain metals (especially aluminum and steel) evolving hydrogen gas
Incompatible Materials: Strong alkalis, strong oxidizing agents, metals, reducing agents
Decomposition Products: Toxic phosphorus oxides and phosphine gas may result from thermal decomposition
Hazardous Polymerization: Will not polymerize
Conditions to Avoid: Extreme heat, contamination with incompatible substances, poor ventilation
Routes of Exposure: Inhalation, ingestion, dermal and ocular exposure
Acute Toxicity: LD50 (oral, rat) ranges from 300-500 mg/kg; severe irritation and extensive burns possible on skin and mucous membrane contact
Symptoms: Burning sensation, coughing, sore throat, skin redness and blistering, severe eye injury
Chronic Effects: Prolonged or repeated exposure may lead to dermatitis and respiratory effects such as coughing and bronchial irritation
Carcinogenicity: No classification by IARC, NTP, or OSHA as to carcinogenic potential
Mutagenicity and Reproductive Toxicity: Evidence for mutagenicity or reproductive toxicity in humans not available or considered low by current studies
Medical Conditions Aggravated by Exposure: Pre-existing skin, eye, and respiratory disorders
Aquatic Toxicity: Harmful to aquatic organisms in high concentrations, may cause pH shift in water bodies
Persistence and Degradability: Dissolves and neutralizes in water, can undergo degradation; high solubility may lead to mobility in soil and water
Bioaccumulation Potential: Low potential based on chemical structure
Mobility in Soil: Highly mobile due to solubility in water, may leach into groundwater if not contained
Other Adverse Effects: Large releases can disrupt aquatic and terrestrial organisms through acidification
Waste Treatment Methods: Neutralize with suitable alkali in a controlled environment before disposal; follow institutional procedures for hazardous waste
Disposal Containers: Use polyethylene or glass containers labeled for acid waste
Regulatory Waste Status: Classified as hazardous waste (RCRA D002: Corrosive Waste)
Precautions: Prevent any spillage or leakage into environment; consult local, state, and national authorities for approved disposal procedures and facilities
UN Number: UN 2834
Proper Shipping Name: Phosphorous Acid, Solution
Transport Hazard Class: 8 (Corrosive Substances)
Packing Group: III
Label Requirements: Corrosive (Class 8)
Special Precautions: Ensure packaging is compatible and resistant to corrosion; emergency response guides available on request; carriers may require SDS prior to acceptance
TSCA: Listed on United States Toxic Substances Control Act Inventory
OSHA Hazardous Chemical: Classified under OSHA 29 CFR 1910.1200
SARA Title III: Not subject to Sections 302, 304, or 313 reporting
REACH Registration: Registered in accordance with EC Regulation No 1907/2006
Canadian WHMIS: Classified as Class E (Corrosive Material)
Other Regulations: Subject to IATA, IMDG, and DOT transport codes; always check the current edition of relevant regulations for shipment and workplace use
