Industrial gas quality refers to the presence of contaminants. These contaminants fall into three main categories: dust, water, and oil – as specified in the international ISO 8573-1 standard. Many industrial applications have specific ISO 8573-1 class requirements, which are more stringent for industries such as pharmaceuticals and food & beverage. Subpar gas quality is a problem for every application, as contamination and corrosion can affect production systems and final products.

This means that gas can be of high purity, but not necessarily of high quality. Purchased gas therefore comes in different industrial, food-grade, and other qualities. Purity is fixed by its production process, while quality can be controlled—often at additional cost.

For example, Atlas Copco nitrogen and oxygen generators comply by default with ISO 8573-1 Class [1:2:1]. With additional filtration, specialized applications can reach Class [1:1:0]. Not every application benefits from the highest class, and over-specifying quality can add unnecessary cost.