© 2026 Nanjing Finechem Holdings Co., Ltd,
All Right Reserved
Product Name: 5,5'-Dithiobis(2-Nitrobenzoic Acid)
Other Names: Ellman’s Reagent, DTNB
CAS Number: 69-78-3
Recommended Use: Laboratory chemical, analytical reagent for protein sulfhydryl group quantification
Supplier: Chemical distributors and laboratory suppliers worldwide
Emergency Phone: Local emergency contact, poison control centers, safety officers
Address: Manufacturer or supplier-advised location, check product label for details
GHS Classification: Eye irritation (Category 2A), Skin irritation (Category 2), Specific target organ toxicity - single exposure (Category 3)
Signal Word: Warning
Hazard Statements: Causes skin and serious eye irritation, may cause respiratory irritation
Precautionary Statements: Avoid contact with skin, eyes, and clothing, do not breathe dust, use only outdoors or in well-ventilated area, wear protective gloves and eyewear
Pictograms: Exclamation mark symbol (Irritant)
Chemical Name: 5,5'-Dithiobis(2-Nitrobenzoic Acid)
Formula: C14H8N2O8S2
Molecular Weight: 396.35 g/mol
Synonyms: Ellman’s Reagent
CAS Registry Number: 69-78-3
Concentration: 100% pure compound in most laboratory containers
Impurities: Not significant in standard reagent grades
Inhalation: Move affected person to fresh air at once, allow for rest, seek medical attention if symptoms persist such as cough or irritation
Skin Contact: Remove contaminated clothing, rinse skin immediately with plenty of water and mild soap, seek further medical advice if redness or irritation develops
Eye Contact: Rinse cautiously with water for at least 15 minutes lifting eyelids occasionally, remove contact lenses if present and easy to do, obtain prompt medical attention
Ingestion: Rinse mouth thoroughly with water and give water to drink, do not induce vomiting, seek immediate medical advice or contact poison control
Suitable Extinguishing Media: Dry chemical, carbon dioxide, foam, water spray applied to cool containers not the chemical directly
Unsuitable Extinguishing Media: Strong water jet directly on powder, can spread hazard
Specific Hazards: Product may decompose emitting toxic fumes of nitrogen oxides and sulfur oxides
Protective Equipment for Firefighters: Wear self-contained breathing apparatus and full protective clothing
Special Procedures: Avoid inhalation of material or combustion by-products, control run-off from firefighting water, isolate hazardous area
Personal Protection: Evacuate unnecessary personnel, ventilate area, wear gloves, goggles, dust mask or respirator and protective clothing
Environmental Precautions: Prevent product from entering drains, sewers or waterways, alert environmental authorities in case of significant spillage
Methods for Cleaning Up: Sweep up and transfer material into suitable container for disposal, avoid creating dust, clean residue with wet cloth or mop—do not dry sweep
Decontamination: Wash spill site with plenty of water after collection is complete
Precautions for Safe Handling: Use in a fume hood if possible, minimize dust generation, avoid contact with skin, eyes, use non-sparking tools and explosion-proof equipment where possible
Information About Fire and Explosion Protection: Keep away from sources of ignition, do not smoke near storage areas, avoid accumulation of dust in workspace
Conditions for Safe Storage: Keep container tightly closed in a dry, cool, well-ventilated area away from incompatible substances such as strong reducing agents and bases
Packing Influence: Use original packaging or chemically compatible containments, avoid using containers previously exposed to incompatible materials
Engineering Controls: Work in chemical fume hood, use local exhaust ventilation to keep airborne levels low, maintain eyewash stations and safety showers nearby
Personal Protective Equipment: Lab coat or apron, chemical resistant gloves (nitrile or neoprene), safety glasses or goggles, respiratory protection if dust levels may become excessive
Hygiene Measures: Wash thoroughly after handling, do not eat, drink or smoke in work areas, change contaminated clothing and clean before reuse
Exposure Limits: No established occupational exposure limits for DTNB, keep exposure to chemical dust at minimal practical levels as per general laboratory practice
Appearance: Yellow crystalline powder
Odor: No significant odor under standard laboratory conditions
Odor Threshold: Not determined for this compound
pH (5% in water): 3.0–4.0
Melting Point: 178–180°C (352–356°F)
Boiling Point: Not applicable – decomposition before boiling
Flash Point: Not flammable under standard conditions
Evaporation Rate: Not volatile
Flammability: Not considered flammable in solid form
Vapor Pressure: Very low at room temperature
Solubility: Sparingly soluble in water, more soluble in organic solvents such as acetone or methanol
Partition Coefficient (n-octanol/water): Not available
Decomposition Temperature: Decomposes above 180°C
Viscosity: Not applicable to solid form
Chemical Stability: Stable under normal conditions of shipping and storage
Reactivity: Reactive with strong reducing agents, incompatible with bases, generates decomposition products upon heating or contact with acids
Hazardous Reactions: No hazardous polymerization expected in standard laboratory setting
Conditions to Avoid: Avoid exposure to excessive heat and moisture, do not mix with incompatible chemicals
Decomposition Products: Nitrogen oxides, sulfur oxides, carbon oxides, possibly other irritating or toxic fumes
Routes of Exposure: Inhalation, skin and eye contact, ingestion
Acute Effects: Skin and eye irritation, coughing or respiratory tract irritation on inhalation
Chronic Effects: No chronic toxicity data reported in humans, possible reactive effects with repeat or prolonged exposure
Symptoms: Redness, burning sensation, stinging, watering of eyes, rash, gastrointestinal upset if ingested
Toxicity Data: LD50 (oral, rat): Not fully established, expected higher than environmental limits for acute risk
Carcinogenicity, Mutagenicity, Reproductive Toxicity: Not classified as carcinogen, mutagen or reproductive toxicant by major regulatory agencies
Sensitization: No data indicating skin sensitization under routine laboratory use
Ecotoxicity: Harmful to aquatic organisms in significant concentrations, limited direct data on full environmental impact
Persistence and Degradability: Organic compound with possible slow degradation in soil and water environments
Bioaccumulative Potential: Likely low, due to molecular size and functional groups, not studied in detail
Mobility in Soil: Expected to have limited mobility due to moderate water solubility and affinity for organic matter
Other Adverse Effects: No evidence of long-lasting environmental harm under standard laboratory waste handling practices; avoid uncontrolled releases to environment
Waste Treatment Methods: Collect chemical waste in designated, compatible containers for hazardous materials, label according to local and institutional protocols
Disposal of Contaminated Packaging: Rinse thoroughly, dispose with chemical waste stream, do not reuse containers for food or consumer products
Precautions for Disposal: Dispose of in accordance with local, regional, national, and international regulations, consult environmental health and safety guidance or hazardous waste coordinator
Recycling: Not practical or safe for material in research context, avoid releasing into regular waste channels
UN Number: Not classified as hazardous material for transportation by ground, air, or sea under current international transport regulations
UN Proper Shipping Name: Not regulated
Transport Hazard Class: None assigned
Packing Group: None
Environmental Hazards: Not designated as marine pollutant or environmentally hazardous for transport
Special Precautions for Users: Ship in tightly sealed containers, clearly marked with chemical name and hazard labeling, carry transport documentation according to workplace protocol
Transport in Bulk: Not applicable—handled in small laboratory quantities
TSCA Status: Listed or exempted as a research chemical under US Toxic Substances Control Act
REACH Status: Not registered for direct consumer use, permitted for professional research and development
OSHA Hazard Classification: Non-flammable irritant
SARA Title III: Not subject to specific reporting under Sections 302, 304, 313
California Proposition 65: Not listed as a chemical requiring warning
Other Federal and International Regulations: Handle in compliance with local workplace and laboratory safety guidelines, consult institutional chemical hygiene plans for updates
