Q：Is long operation in clean room harmful to health?

A：Basically, clean room is a confined space, which may cause the feeling of constraint and oppression to some people. So, it's advisable to install 5~10 mm thick toughened glasses or laminated glasses within 1~2m above the floor, so as to maximize the vision. Also, consideration should be given to interior color matching. Moreover, if RH≤50% in clean room, human skin moisture evaporates fast, thus drinking of more water is recommended.
The major hazards of clean room to human health are diffusion of toxic gas and noise, however, this is preventable by proper planning in most cases.