Generally speaking a confined spaces is an enclosed or partially enclosed space that-
- Is not primarily designed or intended for human occupancy
- Has a restricted entrance or exit by way of location, size or means.
- Can represent a risk for the for the health and safety of anyone who enters due to one or more of the following factors.
- Its design, construction, location or atmosphere.
- The materials or substances in it.
- Work activities being carried out in it.
- Mechanical, process and safety hazards present.
Confined spaces can be below or above ground. Confined spaces can be found in almost any workplace. A confined space, despite Its name, is not necessarily small.
Examples of confined spaces include silos, vats, and hoppers, utility vaults, tanks, sewers, pipes access shafts, and truck or rail tank cars, aircraft wings. Ditches and trenches may also be a confined space access or egress is limited.
What are the Hazards in Confined Spaces?
All hazards found in a regular workspace can also be found in a confined space. However, the can be even more hazardous in a confined space than in a regular work-site. Hazards in confine spaces can include:
- Poor air quality: There may be an insufficient amount of oxygen for the worker to breathe. The atmosphere might contain a poisonous substance that could make the worker ill or even cause the worker to lose consciousness. Natural ventilation alone will often not be sufficient to maintain breathable quality air.
- Chemical exposures due to skin contact or ingestion as well as inhalation of ‘bad’ air.
- Fire hazard: There may be an explosive flammable atmosphere due to flammable liquids and gases arid combustible dusts which if ignited would lead to fire or explosion.
- Process-related hazards such as residual chemicals, release of contents of a supply line.
- Safety hazards such as.
- Moving parts of equipment, structural entanglement; slips and falls.
- Temperature extremes including atmospheric and surface.
- Shifting or collapse of bulk material.
- Barrier failure resulting in a flood or release of free-flowing solid.
- Uncontrolled energy including electrical shock.
- Biological hazards.
How are Confined Spaces more Hazardous Than Working in other Workspaces?
Many factors need to be evaluated when looking for hazards in a confined space. ‘There is smaller margin for error. An error in identifying or evaluating potential hazards can rave more serious consequences. In some cases, the conditions in a confined space are always extremely hazardous. In other cases, conditions are life threatening under an unusual combination of circumstances. This variability and unpredictability is why the hazard’ assessment is extremely important and must be taken every seriously each an every time on is done.
- The entrance/exit of the confined space might not allow the worker to get out in time should there be a flood or collapse of free-flowing solid.
- Self-rescue by the worker is more difficult.
- Rescue of the victim is more difficult. The interior configuration of the confined space often does not aliow easy movement of people or equipment within it.
- Natural ventilation alone will often not be sufficient to maintain breathable quality air.
- The interior configuration of the confined space does not allow easy movement of within it. .
- Conditions can change very quickly.
- The space outside the confined space can impact on the conditions inside the confined space and vice versa.
- Work activities may introduce hazards not present initially.
Preparing To Enter in Confined Spaces
The important thing to remember is that each time a worker ‘plans to enter any workspace, the worker should determine if that work space is considered a confined space. Be sure the confined space hazard assessment and control program has been followed.
The next question to ask is – Is it absolutely necessary that the work be carried out inside the confined space? In many cases where there have been deaths in confined spaces, the work could have been done outside the confined space!
Before to entering any confined space, a trained and experienced person should identify and evaluated all the potential hazards within the confined space. An important step in determining the hazards in a confined space is air testing.
Air quality testing: The air within the confined space should be tested from outside of the confined space before entry into the confined space. Care should be taken to ensure that air is tested throughout the confined space-side-to-side arid top to bottom. A trained worker using detection equipment which ahs remote probes and sampling lines should do the air quality testing. The sampling should show that:
- The oxygen content is within safe limits – not too little and not too much.
- A hazardous atmosphere (toxic gases, flammable atmosphere) is not present.
- Ventilation equipment it operating properly.
- The results of the tests for these hazards are to recorded on the Entry Permit along with the equipment or methods) that used in performing the tests.
- Air testing may need to be ongoing depending on the nature of the potential hazards and the nature of the work.
- Conditions can change while workers inside the confined -space and sometimes a hazardous atmosphere created by the work activities in the confined space.
The traditional risk control methods found in regular work sites can be effective in a confined space. These include engineering controls, administrative controls and personal protective equipment Engineering controls and personal protective equipment try to minimize the contact with the hazard.
However, often because of the nature of the confined space and depending on the ha special precautions not normally required in a regular work site may also need to taken engineering control commonly used in confined spaces mechanical ventilation. The Entry Permit system an example of an administrative control used in confined spaces. Personal protective equipment (respirators, gloves, ear plugs) commonly used in confined spaces as well.
Air Quality Maintained
Natural ventilation (natural air currents) is usually not reliable and not sufficient to maintain the quality. Mechanical ventilation (blowers, fans) is usually necessary to maintain air quality.
- If mechanical ventilation is provided; there should be a warning system in place to immediate notify the worker in the event of a hazard or a failure in the ventilation equipment.
- Care should taken to make sure the air being provided by the ventilation system to the confined space should clean. .
- Ease of air movement throughout the confined space should considered because of the danger of pockets of toxic gases still remaining even with the use of mechanical ventilation.
- Do not substitute oxygen for fresh air. Increasing the oxygen content will significantly increase the risk of fire and explosion.
- The use of mechanical ventilation should be noted on the entry permit.
Work Is Being Done
The should be warning signs to prevent unauthorized entry to the confined space. Anyone working in a confined space must be constantly alert for any changing conditions within the confined space, In the event of an alarm from monitoring equipment or any other indication of danger, workers should immediately leave the confined space. Another worker, the Safety Watch or Standby, posted outside the confined space and continuously monitors the workers inside the confined space.
The Safety watch Duties
- Understands the nature of the hazards that may be found inside the particular confined space and can recognize signs, symptoms and behavioral effects that workers in the confined space could experience.
- Monitors the confined space and surrounding area and is on the look out for dangerous conditions.
- Remains outside the confined space and does no other work which may interface with u primary duty of monitoring the workers inside the confined space.
- Maintains constant communication with the workers in the confined space.
- Orders the immediate evacuation if a potential hazard, not already controlled for, is detected.
- Calls for emergency assistance immediately if an emergency develops.
- Is immediately available to provide non-entry emergency assistance when needed.
- Can provide entry rescue only after the most stringent precautions taken and another Safety Watch immediately available.
- Should a worker leave a confined space for a short time (for example, coffee break, getting additional material for their work.), the confined space should re-tested before the worker re-enters.
- If the confined space has continuously monitored by equipment that can show the details of the atmosphere during the time absent form the confined space and this information can seen from outside the confined space, it can re-entered without retesting.
- If there not continuous air monitoring then the hazard assessment needs to be’ repeated.
- No confined space should closed off until it has verified that no person is inside it.
- After exiting the confined space, the time of exit should be noted on the entry permit.
Entry into ‘Confined Spaces’
A worker was performing TIG welding inside a titanium tank. Argon gas used as a shielding for the weld. The worker was not wearing any respirator equipment. Found unconscious in the tank and died from oxygen deficiency.
“No worker shall enter a tank, vessel, tunnel, sewer or other confined space in which a harmful atmosphere exists or may develop until:
Tests to determine the nature and quantity of harmful vapors, gases, fumes, mists, dusts and oxygen quantity have recorded and written work procedures have established to ensure a safe environment for the worker.
Confined spaces may encountered in virtually any occupation; therefore , their recognition the first step in preventing fatalities, Since deaths in confined spaces often occur because the atmosphere oxygen-deficient or toxic, confined spaces should tested prior to entry and continually monitored, The following references aid in related to confined spaces.
A confined space, a place which substantially enclosed (though not always entirely),and where serious injury can occur from hazardous substances or conditions within the space or nearby(e.g. lack of oxygen).
What is the Emergency Response in Confined Spaces?
If a situation arises where there is a hazardous condition and the worker does net leave or is unable to leave the confined space, rescue procedures should be begin immediately.
The Safety Watch is qualified in confined spaces rescue procedures and will be available immediately outside the confined space to provide emergency assistance if needed. The Safety Watch is in constant communication with the worker inside the confined space and will.
- Have all required rescue equipment (for example, safety harnesses, lifting equipment, and a lifeline) immediately available and trained in its use.
- Have an alarm for calling for help.
- Can do Cardio-pulmonary Resuscitation /Respiration (CPR).
- Hold a basic first aid certificate.
The detailed plan for emergency response to an injury or other emergency within the confined space should described in detail in the Confined Space Hazard Assessment and Control Program.
Rescue the victims from outside of the confined space, if possible. No other worker should enter a confined space to attempt a rescue unless that worker fully trained in the rescue procedures and wearing the appropriate personal protective equipment.” More the 60% of deaths in confined spaces would rescuers, who ‘not fully trained and adequately equipped.
Another worker qualified in confined spaces rescue procedures must be present outside the confined space before the first rescuer enters the confined space. Do not use the same air as the confined space workers your are rescuing. Wear SCBA (self-contained breathing apparatus) or supplied air respirator with an escape bottle.
What are the Worker Training for Confined Spaces?
Yes, appropriate training is extremely important to working safely in confined spaces. Hands-on training should be an essential part of the confined space training.
Every worker that enters a confined space must fully trained on the following:
- Recognition and identification of potential hazards associated with the confined spaces that will entered.
- Evaluation and control procedures for the identified or potential hazards.
- All equipment such as ventilation equipment (blowers), harnesses and air quality monitors (e.g. Oxygen/combustible meters) that will used while in the confined space.
- All personal protective equipment (e.g. respirators) that the worker will be using while in the confined space.
- All procedures for entering the confined space as outlined in the employer’s Confined Space Hazard Assessment Program.
- Procedures to follow in the event of a situation developing that could present additional risk to the worker or an emergency.
- The specific work to be don- while in the confined space.
- Workers with emergency rescue responsibilities will need additional specialized training.
- All confined space training should include some hands-on training with the safety equipment; including the personal protective equipment and safety harnesses.
- Rescue procedures should be practiced frequently so there is a high level of proficiency.
- Employers should “keep records of all confined spaces training including refresher courses.