OSHA defines confined spaces as those with configurations which hinder activities of employees who must enter, work in and exit places that have limited and restricted means for entry or exit, and are not designed for continuous employee occupancy. These can include:
- storage bins
- manholes
- pits
- silos
- process vessels
- pipelines
- underground vaults
- sewers
- wells
- tanks
One or more of the potential hazards of working in Permit-Required Confined Spaces can be a hazardous atmosphere to engulf the entrant, walls that converge inward, or floors sloping downward and tapering into smaller area which could possibly trap or asphyxiate the person, unguarded machinery, exposed live wires, or heat stress.
To prevent accidents, companies should:
- Train employees thoroughly;
- Post proper signs on location;
- Always assume that hazards are present;
- Follow proper lockout/tagout procedures;
- Ensure adequate ventilation for employees;
- Furnish non-sparking tools;
- Provide and ensure required PPE is used at all times;
- Monitor continuously while work is being performed;
- Have rescuers on site and trained for any emergency.
It is estimated that over one and one-half million workers enter confined spaces annually.
Most accidents can be prevented by properly educating the persons who do this work and ensuring that they are adequately supervised at all times.