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Product Name: 4-(2-Hydroxyethyl)Piperazine-1-Ethanesulfonic Acid
Synonyms: HEPES, N-(2-Hydroxyethyl)piperazine-N’-(2-ethanesulfonic acid)
CAS Number: 7365-45-9
Recommended Use: Laboratory chemical, buffer solution preparation, cell culture media
Supplier: Laboratory chemical distributors and major scientific suppliers commonly provide this compound; always use established suppliers with documentation.
Contact Information: Emergency numbers typically come from local authorities or the company SDS service.
Classification: Not classified as hazardous under GHS
Hazard Statements: Prolonged contact may cause mild irritation to skin and eyes; not known to cause acute toxicity in small laboratory exposures.
Signal Words: No signal word required by current classification
Pictograms: None required
Precautionary Statements: Avoid dust formation, wash hands thoroughly after handling, use in a well-ventilated area.
Health Hazards: Limited reports indicate low toxicity, but repeated or high exposures could irritate the respiratory tract.
Chemical Name: 4-(2-Hydroxyethyl)Piperazine-1-Ethanesulfonic acid
Common Name: HEPES
CAS Number: 7365-45-9
Concentration: 98%-100% pure in most laboratory reagents
Impurities: Lower grade material may include minor trace organic or inorganic process residues
Molecular Formula: C8H18N2O4S
Molecular Weight: 238.3 g/mol
Inhalation: Move exposed person to fresh air. Seek medical attention for symptoms such as coughing or difficulty breathing. Always pay attention to symptoms in laboratory settings, as chronic exposures can occur.
Skin Contact: Remove contaminated clothing. Wash affected skin thoroughly with soap and water. Skin irritation is rare but not impossible.
Eye Contact: Immediately rinse eyes with running water for at least 15 minutes. Remove contact lenses. Keep eyelids open, and consult a physician.
Ingestion: Rinse mouth with water. Do not induce vomiting unless advised by a physician. Seek medical attention for large or intentional ingestion.
Most Important Symptoms/Effects: Mild irritation; no systemic effects typically reported at laboratory exposure levels.
Suitable Extinguishing Media: Use water spray, dry chemical, carbon dioxide, or foam. The chemical itself is not highly flammable.
Specific Hazards: Decomposition at high temperature may release small quantities of oxides of nitrogen, sulfur oxides, carbon oxides.
Protective Equipment: Wear self-contained breathing apparatus, protective clothing including gloves and goggles.
Special Procedures: Use standard procedures for chemical fires. Ventilate area immediately after fire has been extinguished.
Additional Advice: Avoid breathing decomposition products and smoke, even though these are unlikely in routine laboratory incidents.
Personal Precautions: Wear gloves, safety glasses, and a dust mask or respirator if dust becomes airborne.
Environmental Precautions: Avoid discharge into environmental drains or watercourses. Collect and dispose according to local regulations.
Method for Cleaning Up: Sweep up spilled material carefully, place in a labeled container for disposal, and wash the spill site with water.
Other Recommendations: Increase ventilation after spill cleanup.
Handling: Handle powder and solutions using laboratory best practices. Use personal protective equipment, avoid inhalation, ingestion, and contact with skin and eyes.
Storage: Store in a tightly closed container, moisture-resistant, in a cool, dry, and well-ventilated location. Keep away from strong oxidizing agents.
Storage Temperatures: Standard ambient laboratory storage works in most settings. Avoid extreme heat or direct sunlight.
Incompatibilities: Do not mix with strong acids, strong bases, or oxidizers.
Occupational Exposure Limits: No established OSHA or ACGIH limits for this material.
Engineering Controls: Use fume hood or local exhaust if working with powders or solutions in large amounts.
Personal Protection: Wear laboratory coat, gloves, and safety glasses. Respirators only needed for dust-generating work.
Hygiene Measures: Wash hands before breaks and after handling the material. Remove contaminated clothing and equipment before leaving the laboratory.
Appearance: White crystalline or powder
Odor: Odorless
Odor Threshold: Not determined
pH: Approximately 5.0–6.5 (0.1 M solution in water)
Melting Point: > 200°C (decomposes)
Boiling Point: Not applicable
Flash Point: Not applicable
Flammability: Non-flammable
Vapor Pressure: Not applicable (non-volatile solid)
Vapor Density: Not applicable
Solubility in Water: Approx. 400 g/L at 20°C
Partition Coefficient (n-octanol/water): Not determined for this substance
Evaporation Rate: Not applicable
Density: 1.49 g/cm³
Other Data: Stable under recommended storage and handling conditions.
Chemical Stability: Stable under standard laboratory and storage conditions.
Reactivity: No dangerous reactions known under normal use.
Possibility of Hazardous Reactions: Contact with strong acids, bases, or oxidizers may cause decomposition.
Decomposition Products: Sulfur oxides, nitrogen oxides, carbon oxides at elevated temperatures.
Conditions to Avoid: Prolonged exposure to heat, moisture, or incompatible chemicals.
Routes of Exposure: Inhalation, swallowing, skin and eye contact
Acute Toxicity: Oral and inhalation toxicity reported as low based on animal studies, LD50 (oral, rat): > 10,000 mg/kg
Skin/Eye Contact: Essentially non-irritating for most users, although transient irritation is possible.
Chronic Effects: No evidence from current literature of carcinogenicity, mutagenicity, or reproductive toxicity.
Sensitization: Not reported as a skin or respiratory sensitizer.
Other Effects: Limited experience suggests material is well tolerated at concentrations used in cell biology and research.
Ecotoxicity: No data on toxicity to fish, daphnia, or algae at concentrations likely met in laboratory waste. Not expected to significantly bioaccumulate or persist.
Mobility: Highly soluble, will dissolve in water, unlikely to bind strongly to soils.
Degradability: Readily biodegradable in standard wastewater treatment systems.
Bioaccumulation: Low potential for accumulation in aquatic organisms.
Other Effects: Caution always pays off—do not dispose large quantities into water systems.
Waste Disposal Method: Chemical waste suitable for landfill after neutralization, or disposal per institutional and local guidelines.
Container Disposal: Empty containers should be rinsed, then discarded in accordance with local chemical waste guidelines.
Special Precautions: Do not flush to sewer in high concentrations. Consult environmental officer for bulk waste.
UN Number: Not regulated as dangerous goods for transport by road, sea, or air
Transport Hazard Class: None
Packing Group: None
Marine Pollutant: Not considered hazardous in shipping but local regulations may differ.
Special Transport Precautions: Standard packaging and shipping procedures for solid laboratory chemicals apply.
Labelling: No hazard labelling required under current GHS or OSHA rules.
TSCA (US): Listed
REACH (EU): Not subject to registration at current production/import volumes.
Other Regulations: Not on lists for carcinogenic, mutagenic, or reproductive toxins from IARC, NTP, ACGIH, or California Prop 65.
Workplace Classification: Professional use only, not for food, drug, or household use.
Other Restrictions: Local and institutional guidelines always supersede generic regulatory information.
