Chemical Name: Nitric Acid
Synonyms: Aqua fortis, Azotic acid
Chemical Formula: HNO3
Appearance: Colorless to yellowish fuming liquid, giving off strong, acrid, choking vapors
Concentration Range: Often shipped commercially around 68 to 70 percent, some processes require fuming grades beyond 98 percent.
Main Use Cases: Steel pickling, chemical manufacturing, explosives, fertilizers, and laboratory applications
Hazard Statements: Severe skin burns, eye damage, causes respiratory irritation, strong oxidizer increasing combustion risk, may be fatal if inhaled in high concentrations
Pictograms: Corrosive, Oxidizer, Health Hazard
Precautionary Labels: Category 1 for skin and eye corrosion, Category 3 for acute inhalation toxicity, oxidizing liquids—risk of fire intensifies with organic material
Emergency Overview: Contact or inhalation results in rapid and severe effects; immediate response needed for spills or exposure
Main Ingredient: Nitric Acid (HNO3), purity generally 68–70 percent
Stabilizers and Impurities: Small traces of nitrogen oxides form during decomposition, water content varies slightly; high-purity grades minimize these
Relevant Impurities: Nitrogen dioxide (NO2) can appear as red fumes during decomposition, especially in older containers
Eye Contact: Flush eyes immediately with plenty of water for at least 15 minutes, seek medical attention—the solution penetrates rapidly and causes irreversible damage
Skin Contact: Remove contaminated clothing, flood skin with running water for no less than 15 minutes, prompt medical evaluation is critical
Inhalation: Remove from exposure to fresh air, give oxygen if breathing is difficult, do not allow exposed personnel to be left alone, medical attention required for any vapor inhalation
Ingestion: Rinse mouth, do not induce vomiting, and medical attention is non-negotiable; the acid will burn esophageal tissue
Suitable Extinguishing Media: Non-combustible itself, use large volumes of water as fog for adjacent fires; dry chemical or CO2 will not cool containers
Special Hazards: Decomposition releases nitrogen oxides, dense brownish fumes, intense oxidizer which can accelerate the burning of other materials
Firefighting Instructions: Move drums from fire area if safe, cool with water spray; full protective acid-resistant gear and SCBA are required for responders
Other Observations: Avoid water jets on acid pools as this reacts violently; bunding prevents uncontrolled runoff contaminated with acid
Personal Precautions: Evacuate area, ventilate, use proper PPE including chemical goggles, acid-resistant gloves, boots, full suit
Environmental Precautions: Prevent runoff to sewers, surface water, and drainage systems; nitric acid poses severe harm to aquatic life
Methods for Cleanup: Neutralize cautiously with sodium bicarbonate or lime, absorb with inert material (sand, vermiculite), collect in non-metallic container suitable for acid waste, rinse spill area thoroughly with plenty of water only after neutralization
Handling: Ensure trained personnel only, use closed systems or ventilated hoods, decant using acid-specific, corrosion-resistant equipment and never mix with combustibles or organics
Storage: Store in cool, secure, well-ventilated area, away from direct sunlight, incompatible chemicals (organic materials, reducing agents, flammables); segregate acids from bases and combustibles, only use containers designed for strong acids, regular inspection for leaks is a practice enforced on our site
Engineering Controls: Use local exhaust and fume hoods, containment for transfer points, permanent acid-resistant work surfaces
Personal Protective Equipment: Full-face shield, non-permeable gloves (nitrile or neoprene), acid-resistant aprons, boots, safety goggles, and in some cases, positive pressure supplied air respirators
Exposure Limits: OSHA PEL: 2 ppm (TWA); ACGIH TLV: 2 ppm (TWA), 4 ppm (STEL), but we run workplace air monitoring for verification; prompt attention to symptoms like coughing or burning ensures exposures are recognized early
Physical State: Strong, fuming liquid
Odor: Choking, acrid, sharp
Color: Transparent to pale yellow, can darken as nitrogen oxides increase
Boiling Point: About 83°C (at 68 percent HNO3)
Melting Point: -41.6°C
Density: 1.41 g/cm³ (at 20°C, 68 percent)
Solubility: Miscible with water; reacts exothermically and can spatter during mixing
Vapor Pressure: Elevated—requires vented storage
Chemical Stability: Stable only in sealed containers, away from contamination and temperatures above ambient
Reactivity: Hyper-reactive with organics, bases, reducing agents, metals, chlorides, and combustibles; even a spill on wooden floors can ignite
Hazardous Decomposition: Decomposes to nitrogen dioxide, nitric oxide, and water vapor under fire or prolonged exposure to air/light
Incompatibles: Do not allow contact with oxidizable substances, metals, or bases; incompatible even with mild reducing agents, some plastics, and most metals except specialized alloys
Acute Toxicity: Severe corneal and dermal burns, pulmonary edema risk upon inhalation, greater effect on children or those with underlying respiratory issues
Chronic Effects: Prolonged exposure results in dental erosion, chronic bronchitis, and skin dermatitis
Routes of Exposure: Inhalation (primary workplace worry, especially when handling high-purity or fuming acid), skin and eye contact prompt immediate injury
Other Findings: No established carcinogenicity, the damage lies in corrosivity and respiratory injury; ongoing worker health monitoring critical
Ecotoxicity: Lethal to aquatic organisms, rapid pH drop in water bodies; releases nitrate ions, leads to eutrophication and oxygen depletion in water life
Persistence and Degradability: Rapidly neutralized and diluted by environmental buffering, but runoff from spills or uncontrolled handling damages flora and fauna in affected zones
Bioaccumulation: Nitrates themselves do not bioaccumulate; ecosystem balance suffers from nutrient loading and acidification
Waste Treatment Methods: Strict neutralization with alkaline agents, dilution, and staged pH monitoring; only designated sites accept acid waste above set thresholds
Disposal Practices: Never allow direct discharge; nitrogen-rich acid neutralized under supervision, waste storage tanks must comply with regional rules; small laboratory residues get collected separately due to risk of incompatible mixing
Regulatory Oversight: Waste manifest tracking ensures any lost volume gets reported and environmental containment remains intact
UN Number: 2031 for commercial grade nitric acid solutions
Proper Shipping Name: Nitric Acid (with less than 70 percent HNO3)
Hazard Class: 8 (Corrosive), subsidiary 5.1 (Oxidizer)
Packing Group: II or I depending on concentration
Special Precautions: Use lined or acid-proof tankers, never load with incompatible cargo, emergency containment preferred over roadside neutralization; transport chain training and regulatory review are entrenched
Workplace Controls: Covered under OSHA hazardous chemicals standard, US EPA and equivalent international directives regulate emissions, handling, and spill reporting
Inventory Status: Fully registered in national chemical inventories for all industrial users; compliance checks routine at bulk sites
Labeling: GHS-compliant labels, clear hazard, and risk communication; proper documentation supplied direct with each shipment, not via intermediaries
Operational Licensing: Site-level licenses require regular audits, and worker training records get reviewed by regulators
