Understanding Nitrogen Purity Grades:
When processes rely on nitrogen, purity matters. From food packaging to electronics manufacturing, the specific nitrogen purity grade used can impact performance, safety, and cost. In this article, we break down the most common nitrogen purity grades, their commonly used applications, and how to choose the right one for your needs.
What Are Nitrogen Purity Grades?
Nitrogen purity grades indicate the percentage of nitrogen in a given gas mixture. Industrial nitrogen is rarely 100% pure. Nitrogen purity is measured by analysing the oxygen content and graded by the number of “nines” in its purity level:
- 99% – Often called commercial-grade nitrogen, this level contains 1% impurities.
- 99.9% – Known as high-purity nitrogen, it’s suitable for many industrial processes including chemical blanketing, food packaging and brewing.
- 99.999% (5.0 grade nitrogen) – Often referred to as ultra-high purity or research grade nitrogen, this grade is essential for semiconductor manufacturing, laboratory analysis, and advanced scientific research.
Why Nitrogen Purity Matters
Different applications demand different levels of nitrogen purity. Using the wrong grade can lead to:
- Product contamination
- Equipment damage
- Regulatory non-compliance
- Reduced shelf life in packaged goods
For instance, the electronics industry requires ultra-high purity nitrogen (5.0 or higher) to prevent oxidation during soldering. Meanwhile, the food industry typically uses 4.0 grade nitrogen to displace oxygen and extend product shelf life.
Common Applications by Purity Grade
| Purity Grade | Purity % | Common Uses |
|---|---|---|
| 2.0 (99%) | Commercial | Tire inflation, fire suppression, LC/MS Instruments |
| 3.0 (99.9%) | Industrial | Heat treating, chemical blanketing |
| 4.0 (99.99%) | High-Purity | Food packaging, beverage preservation |
| 5.0 (99.999%) | UHP | Semiconductor fabrication, lab instrumentation such as GCs |
| 6.0 (99.9999%) | Research | Aerospace, scientific R&D |
