Always consult a manufacturer SDS. Read our Full Liability Disclaimer
Hazard Level & Hazards:
When we create or update chemical disposal entries, our H-code hazard list is generous. We list hazards that may be just below regular cutoffs and would otherwise normally be unlisted. We do this to provide hobbyists a wider scope of safety risks that may still be relevant, despite normally being omitted. Our GHS icons, however, are congruent with typical legal labeling requirements of the respective chemical.
High
- H272: May intensify fire; oxidizer
- H290: May be corrosive to metals
- H314: Causes severe skin burns and eye damage
- H318: Causes serious eye damage
- H331: Toxic if inhaled
Disposal Method
Do not pour nitric acid down any drains. It can be left in its original container and brought to a household hazardous waste facility. If it must be transferred, transfer to a labeled HDPE container.Wear all proper PPE, most importantly gloves and eye protection. Ensure ample ventilation. Even if neutralized to a safe pH, the solution contains nitrates which are regulated in many jurisdictions. First, slowly small amounts of the nitric acid to a container of water. Then slowly add a base like sodium bicarbonate (baking soda) or sodium carbonate (Soda Ash)., which are safe, cheap, and effective. Continue adding the base until the pH is between 6 and 9. The remaining solution is a mixture of water and sodium nitrate.
Neutralizing Agent
Sodium bicarbonate (baking soda), Sodium carbonate (soda ash), calcium carbonate (lime), or sodium hydroxide (lye). Reacts to form water and nitrate salts. Always dilute concentrated acid first and add slowly to control heat and gas (CO₂) production.
Storage Precautions
Store in a sealed HDPE container. Keep in in a cool, dark, dry, well-ventilated area. Employ secondary containment.
Ideal Storage Container
HDPE. Review our chemical storage container guide for more information about container types and materials.
Other Names
Aqua fortis, hydrogen nitrate, spirit of niter, azotic acid,
Additional Tips
- Nitric acid that has turned yellow or brown contains dissolved nitrogen oxides and may behave more aggressively during disposal than fresh, colorless acid.
- Nitric acid used on copper, brass, or steel is no longer just acid. Dissolved metal nitrates can shift it into a different disposal category.
- Long-stored nitric acid can weaken plastics and seals, increasing leak risk during handling or transport for disposal.
- Nitric acid releases significant heat when diluted or neutralized, which is why container choice and sequencing matter.
- After neutralization, nitrate ions remain and still have environmental implications in wastewater systems.
- Many disposal thresholds are based on total amount rather than molarity.
- Small quantities that may be acceptable in municipal systems can disrupt biological activity in septic tanks.
Even highly diluted nitric acid can still act as a strong oxidizer, especially with organic materials.
Incompatible Chemicals/Dangerous Combinations
- Organic Solvents (e.g., Acetone, Ethanol, Acetic Acid) Fire/Explosion – Nitric acid provides oxygen to the fuel (the organic solvent), resulting in a rapid combustion or a high-pressure explosion. Mixing nitric acid with acetone, for example, can create unstable peroxides or trigger a violent exothermic reaction.
- Flammable/Combustible Materials (e.g., Paper, Wood, Cloth) Spontaneous Combustion – Concentrated nitric acid can ignite cellulose-based materials on contact. If a bottle leaks onto a wooden shelf or is wiped up with paper towels, a fire can start several minutes later as the material nitrates and heats up.
- Reducing Agents (e.g., Hydrazine, Sulfides, Nitrites) Violent / Toxic Gas – Nitric acid reacts energetically with reducers. Mixing it with sulfides or nitrites also releases immediate, lethal clouds of hydrogen sulfide (H₂S) or nitrogen dioxide (NO₂) gas.
- Powdered Metals (e.g., Aluminum, Magnesium, Zinc) Explosion / Toxic Gas – Nitric acid reacts with many metals to produce heat and various nitrogen oxides (NOx). In powdered form, the high surface area can lead to a reaction that becomes an explosion, releasing dense, orange-brown toxic fumes.
- Other Strong Acids (specifically Hydrochloric Acid) Toxic Gas – Mixing nitric acid and hydrochloric acid creates “Aqua Regia.” While used in controlled settings to dissolve gold, it is unstable and decomposes to release toxic chlorine and nitrosyl chloride gases. It can never be stored in a closed container as pressure will build up and shatter the glass.