Author: Md Taifur Rahman
Dangers of entering an enclosed space:
- Toxic atmosphere
A toxic atmosphere may cause various acute effects including impairment of judgment, unconsciousness and death.
- Oxygen deficiency
Can be lacking for:
- Displace of air by another gas
- Various biological processes or chemical reaction
- Absorption of air
3. Flammable or explosive atmosphere
A 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.
- 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After completion of work designated person should ensure entry persons and related equipment’s are safely withdrawn.