Product Overview
Nitric Acid 40% is a strong mineral acid supplied as a Technical grade aqueous solution at 40% concentration (HNO₃, CAS 7697-37-2). It is a powerful oxidant and corrosive liquid used across metal finishing, electronics fabrication, water treatment, and chemical processing. This concentration delivers meaningful reactivity while remaining more manageable than fuming grades — a practical middle ground for industrial operations that need oxidizing strength without the extreme hazard profile of concentrated nitric acid.
Alliance Chemical offers this product in sizes from 1-liter bottles to 55-gallon drums, serving both bench-scale work and full production runs.
Why This Concentration
At 40%, this nitric acid sits between the dilute solutions used for pH adjustment and cleaning rinses and the concentrated grades (65–70%) used in aggressive etching and analytical work. For a metal finishing operator or a water treatment facility, 40% provides strong oxidizing action with a lower fuming tendency and reduced thermal sensitivity compared to higher strengths.
If your process calls for a mild acid wash or dilute rinse, Nitric Acid 5% or Nitric Acid 20% may be the better fit — less PPE burden, simpler storage. For passivation baths or moderate pickling, Nitric Acid 25% bridges the gap. When you need full-strength oxidation for aggressive metal dissolution or analytical reagent work, step up to Nitric Acid 65% ACS Grade or Nitric Acid 70% ACS Grade – Low Particle.
The Technical grade designation means this product is sourced and handled for industrial process use — metal etching, pickling, synthesis feedstock, wastewater treatment — rather than for precision analytical work where tighter impurity specifications apply.
Chemical Profile
Nitric Acid 40% is a liquid with a characteristic choking odor. It appears as a pale yellow to reddish brown solution that produces reddish brown vapors. The molecular formula is HNO₃ with a molecular weight of 63.013 g/mol (CAS 7697-37-2). At 40% w/w and 20 °C, the solution has a density of 1.249 g/mL — approximately 12 lb per gallon. It is fully miscible with water and exhibits a vapor pressure of 48 mmHg. The acid is corrosive to metals and tissue, and the vapors are toxic by inhalation.
Industrial Applications
Nitric acid at this concentration serves several established industrial processes:
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Metal etching and pickling. A 40% solution dissolves oxide layers and scale from steel, stainless steel, copper, and brass surfaces. Metal finishing shops use it for surface preparation before plating, welding, or coating. The controlled concentration allows operators to manage etch depth without over-attacking the base metal.
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Oxidizing agent in chemical synthesis. As a strong oxidant, nitric acid serves as a reagent in the production of nitrogen-containing compounds, dyes, and other intermediates. The 40% strength supplies enough oxidizing power for many reaction steps while simplifying feed and handling logistics.
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Water and wastewater treatment. Facilities use nitric acid to adjust pH in process water, neutralize alkaline waste streams, and remove metal contaminants through controlled precipitation or dissolution reactions.
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Electronics fabrication. In semiconductor and circuit board manufacturing, dilute nitric acid etches copper traces and cleans metal surfaces. A 40% concentration can serve as the working bath or as a concentrated feedstock diluted to the target strength on the production line.
Handling & Storage
Nitric Acid 40% carries a signal word of Danger (per the product's GHS classification). The classified hazard statements are:
- H290 — May be corrosive to metals (per the product's GHS classification)
- H314 — Causes severe skin burns and eye damage (per the product's GHS classification)
- H331 — Toxic if inhaled (per the product's GHS classification)
Wear chemical-splash goggles, a face shield, acid-resistant gloves, and a chemical-resistant apron when handling. Use only in well-ventilated areas or under local exhaust ventilation; if vapor concentrations may exceed exposure limits, use an approved acid gas respirator. Avoid breathing vapors.
Store in a cool, dry, well-ventilated area in corrosion-resistant containers — HDPE or borosilicate glass are standard choices. Keep away from organic materials, reducing agents, metals, and bases. Nitric acid is a strong oxidizer that can accelerate the burning of combustible materials or ignite them on contact. Do not store near flammable solvents, sawdust, or rags. Protect containers from physical damage and direct sunlight.
Hazmat & Shipping
Nitric Acid 40% is regulated as a hazardous material for transport. The governing classification:
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UN Number: UN2031 (per 49 CFR 172.101)
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Hazard Class: 8 — Corrosive (per 49 CFR 172.101)
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Packing Group: II (per 49 CFR 172.101)
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Proper Shipping Name: Nitric acid, other than red fuming, with less than 65 percent nitric acid (per 49 CFR 172.101)
All shipments from Alliance Chemical comply with DOT hazmat packaging, marking, labeling, and documentation requirements. Shipping papers accompany every hazmat consignment.
Documentation
A Safety Data Sheet (SDS) ships with every order and is available in English, Spanish, French, and Japanese. A lot-specific Certificate of Analysis (COA) is available on request, documenting the actual assay and key quality parameters for your received lot. A Technical Data Sheet (TDS) is also available for detailed product specifications.
Why Buy from Alliance Chemical
This product ships in DOT-compliant hazmat packaging from our Taylor, TX warehouse — whether you order a single liter or a 55-gallon drum, every container is packaged, marked, and documented to the Class 8 / PG II standard that nitric acid requires. Alliance Chemical has served over 50,000 customers since 1998, and all shipping and handling guidance on this page has been reviewed by Andre Taki, DOT Hazmat Specialist (USDOT #2188383).
