In general, according to the number of dust particles with a diameter greater than or equal to 0.5μm per cubic meter of air, clean operating rooms are divided into:

100 (especially clean): such as heart surgery, prosthesis replacement, organ transplantation, etc.

Grade 1000 (standard cleanliness): plastic surgery, orthopedics, etc.

Grade 10000 (generally clean): otolaryngology, stomatology, gynecology, etc.

Grade 100000 (generally clean): outpatient, emergency, infectious surgery, etc.

The larger the number, the lower the purification level.