Author: Md Taifur Rahman
Dangers of entering an enclosed space:
1. Toxic atmosphere
A toxic atmosphere may cause various acute effects including impairment of judgment, unconsciousness and death.
2. Oxygen deficiency
Can be lacking for:
- Displace of air by another gas
- Various biological process or chemical reaction
- Absorption of air
3. Flammable or explosive atmosphere
Flammable atmosphere present a risk of fire or explosion. Such atmosphere can arise from the presence of flammable liquid or gas or suspended combustible dust in air inside the enclosed space.
4. The flowing dangers may present too like:
- Oxygen enrichment
- Flowing liquid or free flowing solids
- Excessive heat.
Implementation of “Permit-to-enter” system for entry into enclosed spaces:
- Before entering an enclosed space must have a valid permit
- Entry into enclosed space check list must be followed according the SMM manual
- The space must be segregated by blanking off or isolation
- The space must be properly ventilated.
- Proper and practicable atmosphere testing must be carried out.
- Frequent atmosphere check during work must be carried out.
- Must have a continuous Ventilation during work
- Rescue team and related equipment’s including SCBA to be kept ready
- Must have a designated person at the entrance of enclosed space to alert for help.
- Designated person should ensure the entry persons wearing proper PPE with SCBA
- The duty officer in Bridge/ CCR/ECR should be known about the entry
- A reliable means of communication should be agreed and tested.
- In case of failure of ventilation system the person should leave the place immediately.
- There has to be a system to record entry and leaving enclosed space
- A reporting time interval from enclosed space should be agreed.
After completion of work designated person should ensure entry persons and related equipment’s are safely withdrawn.