|  			 Cleanliness  			 |  			 			 Maximum average concentration ofbacteria by sedimentation method(plankton method)  			 |  			 			 Air cleanliness level  			 |  			 			 Reference surgery  			 |  		||
| Operation Area |  			 Around Area  |  			Reference Surgery | Around Area | ||
| Ⅰ |  			 0.2cfu/30minφ90 (5cfu/m³)  			 |  			0.4 cfu /30min φ90 (10cfu/m³)  |  			5 |  			 6  			 |  			Prosthesis implants,certain large organtransplants, surgical siteinfections can directlyendanger life and qualityof life andother operations | 
|  			 Ⅱ  			 |  			 			 0.75cfu/30minφ90 (25cfu/m³)  |  			1.5cfu/30minφ90 (50cfu/m³) | 6 |  			 7  			 |  			Major surger yinvolvingdeep tissues and majororgans of life | 
| Ⅲ | 2.0cfu/30minp90(75cfu/m³) | 4.0cfu/30minφ90(150cfu/m³) | 7 | 8 | Other surgical procedures  |  		
| Ⅳ | 6.0cfu/30min φ90 | 8.5 | Infection and severecontamination surgery | ||









