A guidance document published by the US- American Occupational Safety and
Health Administration helps small businesses to better protect construction
workers from serious injuries and life-threatening hazards.

Because confined spaces are potentially dangerous, employers must evaluate all
confined spaces in which their employees work to determine whether hazards
exist or whether the work to be done in the space can create hazards.

Working in a tight space can prevent a worker from keeping a safe distance from
mechanical and electrical hazards in the space. Fumes from a flammable liquid
that is used in a poorly ventilated area can reach explosive levels. Such
hazards endanger both the workers in the confined space and others who become
exposed to the hazards when they attempt to rescue injured workers.

More information

AplusA-online.de - Source: U.S. Department of Labor