What is a Confined Space:
A confined space is an enclosed area with restricted access and limited ventilation, due to its enclosed nature, it presents a reasonably foreseeable risk.
Examples of Confined Space:
- Tanks,
- Vessels,
- Pipes,
- Sewers,
- Silos,
- Storage bins,
- Hoppers,
- Vaults,
- Pits,
- Deep excavations,
- Manholes or other similar spaces.
Foreseeable risks in a confined space include, but not limited to:
- Loss of consciousness of any person caused by lack of ventilation thus deficiency in oxygen, or presence of any harmful gases,
- Potential fire and explosion from flammable gases, vapours or dust,
- Drowning of any person from increase in the level of liquid,
- Asphyxiation of any person from free flowing solid, inability to reach as respirable environment due to entrapment by a free following solid,
- Possible attack by any harmful species such as snakes, scorpions, etc.
What are the Common Hazards associated with Confined Space?
- Toxic atmosphere in the presence of harmful gases, commonly CO or H2S,
- Oxygen deficiency,
- Oxygen enrichment,
- Flammable or explosive atmosphere,
- Free flowing solids or liquids,
- Excessive heat/ humidity, etc.
What are the additional Risks associated with Confined Space?
- Presence of harmful species such as snakes and scorpion inside confined space when it is not being used or maintained for a long period,
- Water flood caused by leakage of pipeline inside the confined space,
- Stagnant/ contaminated water or other waste that can be septic,
- Electrocution risks from wet surface while using power tools, lights, ventilation, etc. inside the Confined Space,
- Entering inside the Confined Space without assessment by a competent person or with lack of knowledge in the foreseeable risk,
- Poor planning and preparation causing difficulty in emergency evacuation and/or rescue, etc.
What measures shall be taken to safely enter and/ or work inside a Confined Space?
The initial step should be thorough planning and assessment. All confined space activities must be planned in advance and a risk assessment should be conducted by competent personnel.
- Eliminate the need for entering the Confined Space where possible,
- Mandatory third-party training and certification for all operatives involved in Confined Space entry,
- Training should include on-site practical demonstrations,
- Entry must be strictly restricted and controlled by issuing Permit to Work,
- Atmospheric testing using a calibrated multi-gas detector to verify the level of Oxygen, and to identify the presence of any harmful gases (must be recorded in the PTW),
- Provision of adequate ventilation, preferably forced ventilation and exhaust ventilation to remove the presence of any toxic gases,
- Performing atmospheric test again to verify that the Oxygen level is within the safe limit and there is no presence of other toxic gases (must be recorded in the PTW),
- Ensure the atmospheric Oxygen concentration levels inside the Confined Space between 19.5 & and 23.5%,
- Verify and conclude at this stage the necessity of using breathing apparatus to the personnel entering when there is a chance of continuous emission even after providing ventilation,
- Provision of safe access and egress for personnel to comfortably enter and exit from the confined space,
- Appoint safety watch personnel, who must be trained and certified as well,
- Safety watch personnel must ensure constant communication with the personnel entering inside the confined space (Provide walky-talky if necessary),
- Assess the area where there is any chance for free flowing solid or liquid into the confined space which must be stopped and evaluated before starting confined space entry,
- Assess the atmosphere inside the confined space to verify whether it is flammable or explosive in nature, if so, careful consideration must be given in selecting tools such as intrinsically safe,
- Ensure the concentration of any flammable gas or flammable vapour, as determined by the testing required is less than 5% of its LEL (Lower Explosion Limit),
- All confined space must be identified, demarcated with warning signs and restrict the entry,
- Provide personnel rescue equipment such as tripod with winch connected with Full Body Safety Harness of the personnel entering to rescue them in case of emergency,
- In such emergency cases, no personnel shall be entering the confined space where there is a chance of repetition of the same incident,
- It is important that no personnel enter inside the Confined Space either to rescue or in the event when there is no response from the personnel entered inside the Confined Space,
- Upon completing a job, the responsible Engineer and OSH Advisor must inspect the area to ensure it is safe. Once confirmed, they shall sign off and close the Confined Space Permit to Work.
What are the Additional Controls Measures that we should think of before starting a Confined Space Activity?
- Health screening and selection of fit employees for the job,
- Excavation deeper than 3-meter height must be considered as a Confined Space,
- General awareness must be given to all operatives and supervisory staff even if they are not required to enter a Confined Space,
- Personnel entry must be monitored and recorded in the Permit to Work.
- Implement a job rotation system to reduce the exposure and possible drowsiness of the personnel inside the confined space for longer time,
- A safe system of work to be developed after reviewing the Method Statement and Risk Assessment, and train the personnel involved,
- While issuing the PTW, ensure the PTW is valid for a shift only and it must be closed at the end of the shift,
- Practice emergency rescue drills more frequently to see the effectiveness.
Yes indeed, answer to the title question; entering or working inside a Confined Space can be extremely dangerous if not properly risk assessed and managed. While we have learned about the various risks and safety measures associated with Confined Space entry, it is essential to anticipate the unexpected and practice emergency response proactively, rather than waiting for an incident to happen.
Shamal Swamidas CMIOSH
