Nitric Acid

About Nitric Acid

Buy nitric acid (HNO3, CAS 7697-37-2) in concentrations from 5% to 70% from Alliance Chemical. Available in ACS Reagent Grade and Technical Grade, with sizes ranging from 1-liter bottles to 55-gallon drums for laboratory, semiconductor, and industrial applications.

Products In This Collection

This collection includes nitric acid 70% ACS Grade Low Particle, nitric acid 69% ACS Grade in 55-gallon drums, nitric acid 65% ACS Grade, nitric acid 40% Technical Grade, nitric acid 25% Technical Grade, nitric acid 20% Technical Grade, and nitric acid 5% Reagent Grade. The 70% Low Particle grade features minimized particulate contamination for semiconductor and trace-metal work.

Common Applications

Nitric acid 70% ACS Grade is the standard for HPLC sample preparation, semiconductor wafer etching, and ICP-MS trace metal digestion where high purity and low particulate counts are critical. The 65% ACS grade serves general analytical chemistry, metal passivation, and chemical synthesis. Lower concentrations (5%–40%) are used for controlled metal etching, pH adjustment in water treatment, stainless steel surface treatment, and gold refining. Nitric acid is also combined with hydrochloric acid to form aqua regia for dissolving noble metals in assay and refining operations.

Why Buy From Alliance Chemical

All nitric acid products ship with Safety Data Sheets (SDS) and lot-specific Certificates of Analysis (COA). Alliance Chemical provides same-day shipping on in-stock orders, no minimum purchase requirements, and proper DOT-compliant packaging for this Class 8 corrosive and Class 5.1 oxidizer.

Related: See the Acids collection. Blog: “Understanding Chemical Grades: ACS vs Technical.”

Frequently Asked Questions

What concentration of nitric acid is used for stainless steel passivation?

Industrial passivation typically requires nitric acid concentrations between 20% and 50% by volume. According to ASTM A967, the process often occurs at temperatures ranging from 70°F to 140°F (21°C to 60°C) for a duration of 20 to 30 minutes. This treatment removes free iron from the surface and promotes the formation of a protective chromium oxide layer.

What is the shelf life and proper storage for Nitric Acid 70%?

Nitric acid has a shelf life of approximately two years when stored in its original, unopened container in a cool, dark environment. Exposure to light and heat causes the acid to decompose into nitrogen dioxide (NO₂), which results in a yellowish tint. It must be stored in secondary containment away from organic materials, as it is a powerful oxidizer that can ignite combustible substances.

How should nitric acid be neutralized for disposal?

Nitric acid disposal is regulated under EPA RCRA as a D002 corrosive hazardous waste. Small laboratory quantities can be neutralized by slowly adding the acid to a large volume of cold water, followed by the addition of a neutralizing agent like sodium bicarbonate (baking soda) until a neutral pH of 6-8 is achieved. Large industrial quantities must be managed by a licensed hazardous waste professional in accordance with 40 CFR 261.

Can nitric acid be stored in stainless steel containers?

Nitric acid can be stored in specific high-chromium stainless steel alloys, such as 304L or 316L, because the acid's oxidizing nature passivates the metal. However, at concentrations above 70% (fuming nitric acid) or at elevated temperatures, the corrosion rate increases significantly. For most commercial 40% to 70% grades, glass or specialized fluoropolymers like PTFE and HDPE are the preferred materials for long-term storage.

What are the DOT shipping requirements for nitric acid?

Nitric acid is regulated by DOT 49 CFR 172.101 as UN2031. It is classified as a Class 8 Corrosive material, and concentrations exceeding 65% require a secondary 'Oxidizer' (5.1) hazard label. All shipments must utilize UN-rated packaging, and transport is subject to strict quantity limitations on passenger aircraft and rail.

What is the difference between ACS Grade and Technical Grade Nitric Acid?

ACS Grade Nitric Acid meets or exceeds the purity standards set by the American Chemical Society, featuring extremely low metal and particle counts suitable for analytical research. Technical Grade is intended for industrial processes where minor impurities (such as iron or chlorides) do not interfere with the application. For semiconductor and electronic uses, a 'Low Particle' ACS grade is specifically filtered to remove contaminants that could damage microcircuits.

What PPE is required by OSHA for handling nitric acid?

Under OSHA 29 CFR 1910.132, employers must provide appropriate PPE for the hazards presented by nitric acid. This includes a full-face shield over chemical splash goggles to prevent eye and face contact. Hand protection must consist of acid-resistant gloves made of butyl rubber or neoprene, as standard thin nitrile gloves may degrade quickly when exposed to high concentrations.

What concentration of nitric acid is used for gold refining?

In gold refining, 67-70% nitric acid is used to create Aqua Regia (a 3:1 mixture of hydrochloric acid and nitric acid) which dissolves gold. Alternatively, it is used alone at approximately 30-40% concentration to dissolve base metals like silver and copper out of a gold alloy, a process known as inquartation. This process must always be conducted under a high-efficiency fume hood due to the release of toxic nitrogen oxide fumes.