有限空间是指封闭或部分封闭,进出口较为狭窄有限,未被设计为固定工作场所,自然通风不良,易造成有毒有害、易燃易爆物质积聚或者氧含量不足的空间。夏季温度较高,各种有毒有害气体聚集和挥发的程度比较高,污水井、下水道内有毒气体浓度要比以往高,所以发生有限空间中毒窒息事故大大增加。有限空间容易 Limited space refers to the enclosed or partially enclosed, limited import and export is limited, not designed to be a fixed workplace, poor natural ventilation, easy to cause toxic and harmful, flammable and explosive material accumulation or lack of oxygen space. In summer, the temperatures are higher, the concentration and volatilization of various toxic and harmful gases are relatively high, and the concentration of toxic gas in sewage wells and sewers is higher than ever before. As a result, the occurrence of suffocation in limited space is greatly increased. Limited space is easy