Product Name: Etidronic Acid
Chemical Name: 1-Hydroxyethane-1,1-diphosphonic acid
Synonyms: HEDP, Etidronate
Recommended Use: Water treatment, detergent additive, scale inhibitor
Uses Advised Against: Use outside industrial or laboratory settings
CAS Number: 2809-21-4
EC Number: 220-552-8
Molecular Formula: C2H8O7P2
Molecular Weight: 206.03 g/mol
Manufacturer Contact: See supplier's details on packaging
Emergency Telephone: Refer to national poison center for assistance
GHS Classification: Eye Irritation (Category 2A), Skin Irritation (Category 2), Corrosive to Metals (Category 1)
Label Elements: Warning, corrosive pictogram
Hazard Statements: Causes skin irritation; causes serious eye irritation; may be corrosive to metals
Precautionary Statements: Avoid breathing mist or vapor, wash hands thoroughly after handling, wear protective gloves, protective clothing, and eye protection
Potential Health Effects: Prolonged contact damages tissues, eye injury possible, ingestion may result in gastrointestinal issues
Environmental Hazards: Harmful to aquatic organisms with long-term effects
Signal Word: Warning
Chemical Identity: Etidronic Acid
Concentration: ≥60% (depending on specification and supplier)
Common Impurities: Water, trace phosphoric acid compounds
Hazardous Components: No additional hazardous ingredients identified above reporting limits.
Ingredient CAS Number: 2809-21-4
Form: Powder or liquid solution
EC Number: 220-552-8
Inhalation: Move person to fresh air, keep comfortable for breathing, seek medical attention if symptoms develop
Skin Contact: Remove contaminated clothing immediately, rinse affected skin with water for at least 15 minutes, seek medical advice if irritation persists
Eye Contact: Rinse cautiously with water for several minutes, remove contact lenses if easy, continue rinsing, get medical help promptly
Ingestion: Rinse mouth, do not induce vomiting, seek medical attention immediately
Most Important Symptoms: Burning sensation, redness, eye damage possible, nausea, vomiting
Immediate Medical Attention Needed: Eye exposure, ingestion, severe skin irritation
Suitable Extinguishing Media: Water spray, dry chemical, foam, carbon dioxide
Unsuitable Media: Do not use high volume water jets
Specific Hazards: Thermal decomposition can release oxides of phosphorus, carbon monoxide, carbon dioxide
Protective Equipment: Wear self-contained breathing apparatus, full protective gear
Special Procedures: Cool exposed containers with water spray to prevent overheating
Fire/Explosion Risks: Not flammable but may corrode metals releasing hydrogen under certain conditions
Hazardous Combustion Products: Phosphorous oxides, carbon oxides, possibly irritating fumes
Personal Precautions: Avoid contact with skin and eyes, wear appropriate personal protective equipment including gloves and goggles
Environmental Precautions: Prevent entry into drains, waterways, or soil, contain spill to minimize environmental impact
Spill Cleanup Methods: Absorb spill with inert material (sand or earth), shovel into a suitable container for disposal, decontaminate area with water
Secondary Hazards: Surfaces may become slippery, spill area may corrode metals
Emergency Procedures: Evacuate unnecessary personnel, ventilate area, consult relevant authorities as needed
Handling: Use only with adequate ventilation, avoid breathing vapor or mists, avoid contact with skin, eyes, and clothing, wash hands after handling
Storage Conditions: Store in original tightly closed container, keep in a cool, dry, well-ventilated location
Incompatibilities: Strong alkalis, oxidizing agents, reactive metals (aluminum, zinc)
Material of Construction: Use corrosion-resistant equipment
Other Precautions: Keep away from food, beverages, and animal feed, store away from incompatible substances
Engineering Controls: Use fume hoods, local exhaust ventilation to control airborne concentration
Occupational Exposure Limits: No established occupational exposure limits for etidronic acid; follow guidelines for general chemical exposure
Personal Protective Equipment: Chemical resistant gloves (nitrile, PVC), safety goggles or face shield, long sleeves and pants, protective footwear
Respiratory Protection: Approved respirators if airborne concentrations exceed control limits or ventilation is inadequate
Hygiene Measures: Do not eat, drink, or smoke during use, wash exposed skin after handling, remove contaminated clothing promptly
Environmental Controls: Prevent release into the environment, monitor air and water quality as required
Appearance: White crystalline powder or clear, colorless to yellow liquid solution
Odor: Odorless
Odor Threshold: Not determined
pH: 1.5–2.0 (1% solution)
Melting Point/Freezing Point: 198–205 °C (decomposes)
Boiling Point: Decomposes before boiling
Flash Point: Not applicable
Evaporation Rate: Not determined
Flammability: Non-flammable
Upper/Lower Flammability Limits: Not applicable
Vapor Pressure: Negligible at room temperature
Vapor Density: Not determined
Relative Density: 1.5–1.7 g/cm³
Solubility: Soluble in water
Partition Coefficient (n-octanol/water): Not determined
Auto-ignition Temperature: Not applicable
Decomposition Temperature: 198–205 °C
Viscosity: Not determined
Chemical Stability: Stable under recommended conditions for storage and use
Reactivity: Reacts with alkalis, reactive metals, oxidizers
Risk of Hazardous Reactions: Hydrogen gas may form when reacting with metals
Incompatible Materials: Strong bases, strong oxidizing agents, reactive metals
Conditions to Avoid: Excessive heat, direct sunlight, contact with incompatible substances
Hazardous Decomposition Products: Phosphorus oxides, carbon oxides, possibly corrosive vapors
Likely Routes of Exposure: Inhalation, skin and eye contact, ingestion
Acute Toxicity: Oral LD50 (rat): 1,800 mg/kg; Dermal LD50 (rabbit): > 7,940 mg/kg
Skin Corrosion/Irritation: Causes irritation; repeated exposure increases severity
Eye Damage/Irritation: Severe irritation or injury possible
Respiratory Sensitization: Not a respiratory sensitizer in standard studies
Skin Sensitization: Not expected to cause sensitization
Chronic Effects: Prolonged exposure may damage tissues, repeated ingestion may impact bone mineralization
Carcinogenicity: Not classified as carcinogenic by IARC, NTP, or OSHA
Reproductive/Developmental Toxicity: No evidence of reproductive toxicity in animal studies
Mutagenicity: Not considered mutagenic
Other Health Effects: Nausea, abdominal pain, vomiting upon ingestion
Toxicity to Aquatic Organisms: LC50 (fish, 96h): 368 mg/L (Lepomis macrochirus); EC50 (Daphnia, 48h): 527 mg/L
Persistence and Degradability: Slowly biodegradable under environmental conditions, may persist
Bioaccumulative Potential: Low potential for bioaccumulation
Mobility in Soil: High mobility due to water solubility
Other Adverse Effects: Alters water chemistry; excess may foster eutrophication in aquatic systems
Disposal Methods: Dispose of in accordance with local, regional, and national regulations
Used Containers: Rinse thoroughly before recycling or discard as hazardous waste
Waste Authorization: Consult licensed waste disposal company
Avoid: Release into sewer or natural waterways
Disposal Code: None specifically assigned; follow chemical waste guidelines
Note: Follow local environmental authority guidelines to ensure safe treatment
UN Number: UN3265
UN Proper Shipping Name: Corrosive Liquid, Acidic, Organic, N.O.S. (contains Etidronic Acid)
Transport Hazard Class: 8 (Corrosive substances)
Packing Group: III
Label: Corrosive
Environmental Hazards: Not a marine pollutant under IMDG
Special Precautions: Avoid package damage, ensure proper secondary containment, emergency response kits recommended for bulk transport
Regulatory Transport Info: Complies with ADR/RID, IMDG, IATA guidance for hazardous materials
OSHA Status: Regulated under the US Hazard Communication Standard
TSCA (United States): Listed on the Toxic Substances Control Act inventory
REACH (EU): Substance registered; Safety data available upon request
SARA Title III: Not subject to reporting under Sections 302, 304, 313
Canada DSL: Substance present on Domestic Substances List
WHMIS Classification: D2B (Toxic material causing other toxic effects)
Other Regulations: Subject to chemical safety assessment and workplace labeling rules
Restrictions: Not for pharmaceutical or food use except by licensed manufacturers
International Inventory Status: Listed on AICS (Australia), ENCS (Japan), ECL (Korea), PICCS (Philippines), NZIoC (New Zealand)
