© 2026 Nanjing Finechem Holdings Co., Ltd,
All Right Reserved
Chemical Names: Sodium dihydrogen phosphate (monosodium phosphate), disodium hydrogen phosphate (disodium phosphate)
CAS Numbers: 7558-80-7 (disodium), 7558-79-4 (monosodium)
Typical Appearance: Colorless crystals or white granular powder
Common Uses: Water treatment, food additives, cleaning agents, laboratory reagents
Classification: Not usually classed as hazardous, though dust may cause irritation
Main Health Concerns: Extended skin or eye contact can result in irritation. Inhalation sometimes aggravates symptoms for asthmatics.
Signs of Exposure: Red, itchy skin or eyes; cough and throat discomfort after breathing dust; upset stomach if swallowed
GHS Symbols: Often no pictogram, though exclamation mark may appear for minor irritancy
Monosodium Phosphate: NaH2PO4, purity often above 98% by weight
Disodium Phosphate: Na2HPO4, similar purity
Contaminants: Trace calcium, magnesium, or other sodium salts depending on source
Inhalation: Move person to fresh air, encourage deep breathing
Skin Contact: Wash thoroughly with soap and water
Eye Contact: Rinse gently with plenty of water, remove contact lenses if present
Ingestion: If large amounts are swallowed, encourage the person to drink water; seek medical guidance for persistent discomfort
Flammability: Product does not burn, so it won't ignite on its own
Hazardous Byproducts: When heated extremely, sodium oxides or phosphorus oxides may form
Firefighting Methods: Use standard extinguishers such as water spray, foam, or dry chemical
Personal Precautions: Limit dust generation, ventilate area
Containment Steps: Sweep up carefully and avoid scattering dust
Clean-Up: Shovel or sweep into containers for disposal; wipe down remaining powder with a damp cloth
Handling: Avoid creating dust, use with adequate ventilation, wear gloves and goggles if handling large quantities
Storage: Keep in tightly closed containers, store in a dry place, away from acids since phosphate reacts with strong acids to release phosphoric acid fumes
Ventilation: Good airflow in handling and mixing areas reduces exposure
Eye Protection: Safety goggles protect against splashes and dust
Skin Protection: Gloves made from materials like nitrile limit skin contact
Respirators: Only needed for prolonged use in dusty environments
Occupational Exposure Limits: Not rigidly set, though OSHA total particulate PEL of 15 mg/m³ applies
Physical State: Solid, usually as granules or powder
Color: White, sometimes translucent crystals
Solubility: High in water, leaving a slightly alkaline solution
Odor: Odorless
pH: Monosodium phosphate gives acidic solutions; disodium phosphate gives mildly alkaline solutions
Stability: Chemically stable under normal temperature and moisture
Incompatible Materials: Strong acids, some aluminum compounds
Hazardous Reactions: Strong acid can break down phosphate, producing irritating mist or fumes
Decomposition: Heating above several hundred degrees Celsius may produce sodium oxide and phosphorus oxide fumes
Possible Health Effects: Acute exposure can irritate the eyes, skin, or upper airways
Chronic Health Effects: Repeated contact may dry or crack skin
Ingestion Toxicity: Large doses can upset stomach, but significant harm is rare unless excessive amounts are consumed intentionally
Cancer, Mutagenicity, Reproductive Toxicity: No strong links to long-term health effects or cancer documented for human exposure
Environmental Impact: At high concentrations in waterways, sodium phosphate promotes algal blooms, which damage aquatic ecosystems
Persistence: Phosphates dissolve and spread quickly in water
Bioaccumulation: Does not build up in living tissue, but large inputs can shift local nutrient cycles
Aquatic Toxicity: Large amounts can kill fish and disrupt water quality by depleting oxygen as algae die and decompose
Waste Treatment: Collect and send bulk waste off-site for appropriate chemical disposal
Sewage Impact: Never dump directly to surface water or sewers; phosphate feeds unwanted algal growth downstream
Container Disposal: Rinse thoroughly; recycle or landfill according to local environmental rules
UN Number: Usually not regulated under bulk shipping codes
Hazard Class: Not generally considered hazardous for ground, air, or sea transport
Packing: Transport in secure, moisture-proof packaging to prevent spills and caking
Major Guidelines: EPA sets limits for phosphate additions to waterways given its role in eutrophication
OSHA Considerations: General chemical hygiene rules apply
Food Additive Status: Certain grades approved as food additives within recommended limits
Restrictions: Some municipalities regulate phosphate in detergents and cleansers to curb pollution
