三级生物安全实验室通风中的问题及改进方法

Suggestions on the Ventilation Design for Biosafety Level-3 Laboratory

目的 为改进三级生物安全实验室（BSL-3实验室）建设及今后修订规范提供参考。方法对BSL-3实验室验收检测中的压强、空气洁净度、气流组织、污染空气的处理等提出问题并讨论。空气洁净度、压强、空气流速分别采用了光电粒子计数器、微压计、热电风速仪测量。仪器均经计量单位年检。结果①BSL-3附属用室至主实验室应保持逐渐增高的负压值，主实验室的负压值满足规范的要求即可，负压过高将对洁净度产生不利影响；②使BSL-3实验室的空气达7—8级的洁净度，除了保证一定的通风换气次数外，尽量减少室外未经过滤的空气漏入BSL-3实验室是关键，其中包括：实验室墙壁的缝隙、电源插座、进风高效过滤器接口、消毒设备与墙壁连接处的漏风等；③为屏蔽开门时外界未经处理的空气流入BSL-3实验室，洁净区的“一更”宜设计为微正压；④排风高效过滤器应设在实验室围护结构的风口里，精细施工，以确保无泄漏，并设在线检漏测孔；⑤将生物安全柜的排风纳入BSL-3主实验室的排风系统，并建立送、排风和生物安全柜排风连锁装置，确保进入实验室时先开排风，后开送风及生物安全柜内的空气不倒流。结论上述改进措施实施后，可使BSL-3实验室达到验收标准。

Objective To improve the ventilation design for the biosafety level 3 （BSL- 3） laboratory and the regulations for design, based on the results of BSL- 3 laboratory acceptance tests, the paper investigated the key parameters based on the ventilation design for BSL- 3 laboratory which included the pressure intensity , air cleanliness , air change rates, air flow pattern, the treatment of the exhaust air, etc. Methods Pressure intensity, air cleanliness, and air velocities of the lab were measured by the manometer, photoelectric particle counter, and thermo- electric anemometer respectively, all of them had been examined by the authorized qualitative units. Results ① The negative pressure intensity from the BSL - 3 subordinate rooms to the BSL - 3 main room should be increased gradually, the negative pressure of the BSL- 3 main room should not be too higher than the（BSL - 3 regulations ）stated. ; ② To maintain the air cleanliness of BSL - 3 rooms at class 7 -8, apart from the necessary air change times, the key factor was minimizing the outside air leaking into the BSL - 3 rooms which included： air leaks thru the enclosing walls; air leaks thru the electrical plugs; air leaks thru the connections between the supply air pipe and the HEPA filter unit; air leaks thru the connections between disinfecting apparatus and enclosing wall, ere ; ③ To prevent the outside air flowing into the BSL - 3 primary dressing room thru the entrance gate, the dressing room should be designed at a low positive pressure; ④ HEPA filter units ＇ for the exhaust air should be carefully installed in the surrounding wall of BSL - 3 main room to guarantee there were no air leaks thru the connections between the HEPA filter and the exhaust air pipe, sample ports behind the HEPA filter units should be provided for on - line check of air leaks ; ⑤ Installing the supply air and exhaust air automatic control system, and the exhaust air from the biosafety level - 2 cabinet should be conducted by pipes to the exhaust ventilation system of the BSL - 3 main room , so that when entering the BSL - 3 rooms, exhaust air turned on firstly and supply air turned on secondly, there were no reverse air flows of the biosnfety level - 2 cabinets with the cabinet exhaust blowers turned off and the BSL - 3 room under negative pressure. Conclusion After adopting the above control measures, the key parameters of BSL- 3 lab could meet the（BSL - 3 regulations ）requirements.