When introducing production hardware, cleanrooms are often a crucial component because cleanliness is vital for production processes in specific industries. The ISO 14644-1 standard, developed by the International Organization for Standardization (ISO), specifies requirements for air cleanliness in cleanrooms and controlled environments, providing detailed regulations for cleanliness classification.

ISO cleanliness classes are primarily divided based on the concentration of airborne particles. Fewer particles correspond to a higher cleanliness class. The ISO standard defines 9 classes, from ISO Class 1 (highest air cleanliness) to ISO Class 9 (lowest air cleanliness). The ISO cleanroom standards apply to general cleanrooms across industries like electronics, food, and chemicals.

Generally, air quality rated as "excellent" in cities can be considered close to ISO Class 9. The cleanliness requirement for obstetrics delivery rooms is typically ISO Class 8. The cleanroom requirement for testing and packaging areas in chip foundries is generally ISO Class 6, while the production areas for chips commonly require at least ISO Class 3. As for ISO Class 1, it requires no more than 10 particles of 0.1μm per cubic meter of space.

Additionally, ISO Classes 4-8 roughly correspond to the domestically used terms "Class 10" to "Class 100,000". For example, a "Class 1,000" cleanroom corresponds to ISO Class 6.

When it comes to pharmaceutical-related enterprises, the GMP (Good Manufacturing Practice) standard is typically adopted. This standard also classifies cleanroom air cleanliness similarly. GMP categorizes cleanliness into four grades: A, B, C, and D, with Grade A representing the highest requirement and Grade D the relatively lowest. Different pharmaceutical production activities require different cleanliness grades according to GMP regulations. For instance, sterile pharmaceutical production requires cleanrooms meeting Grade A or B, while non-sterile pharmaceutical production can use Grade C or D cleanrooms.

GMP also classifies cleanliness based on the concentration of airborne particles. Although slightly different from the ISO standard, a rough conversion is possible. For example, according to GMP, a Grade D cleanroom requires no more than 3,520,000 particles per cubic meter, roughly equivalent to ISO Class 8. These standards and grades aim to ensure a clean environment during pharmaceutical manufacturing to safeguard product quality and safety. Different cleanliness requirements apply to different types of pharmaceutical activities to meet the specific production needs and regulatory requirements of the products.