Confined Space Entry: Hazards and Safety Measures Guide

OBJECTIVES

Upon completion of this lesson you will be able to:

• Define Confined Space
• Describe Hazards of Confined Space
• Explain Control measures for Confined Space Entry
• Describe the Use of Wiser Application

1. Confined Space:

Confined space is space that:

1. Has limited or restricted means for entry or exit (i.e., tanks, vessels, silos, pits, vaults, or hoppers).
2. Is not designed for continuous employee occupancy.

2. Hazards in Confined Space

1. Toxic Atmosphere
2. Oxygen Deficiency
3. Oxygen Enrichment
4. Flammable or Explosive Atmospheres
5. Excessive Heat
6. Slippery Surface
7. Poor Illumination

3. Control Measures for Confined Space Entry Monitoring:

Multi-Gas Detector shall be used for the monitoring of Oxygen Level, Toxic Gases & Flammable gases.

3.1. Oxygen Concentration:

• Oxygen Deficiency → less than 19.5%
• Oxygen Enrichment → more than 23.5%

3.2. Toxic Gases:

• STEL (Short Term Exposure Limit) → 15 mins
• TWA (Total Weighted Average) → 40 hr/week
• IDLH (Immediate Danger to Life & Health)

3.3. Flammable Limits:

3.3.1. LEL (Lower Explosive Limit):

• “Lower Explosive Limit” is defined as the lowest concentration (by percentage) of a gas or vapor in air that is capable of producing a flash of fire in the presence of an ignition source.

3.3.2. UEL (Upper Explosive Limit):

• The maximum concentration of a gas or vapor that will burn in air is defined as the Upper Explosive Limit (UEL). Above this level, the mixture is too “rich” to burn.

Note:
Atmospheres with a concentration of flammable vapors at or above 10 percent of the lower explosive limit (LEL) are considered hazardous when located in confined spaces.

3.4. Confined Space Entry Permit:

The Confined Space Entry Permit is the major tool in assuring safety during entry into confined spaces with known hazards or with unknown or potentially hazardous atmospheres.

3.4.1 Components of Permit:

• Purpose of the entry
• Date of the permit and the duration of the entry
• Name of authorized entrants
• Personnel serving as attendants
• Individual serving as entry supervisor
• Hazards of space to be entered
• Acceptable entry conditions
• Rescue and emergency services that can be summoned
• Communication procedures used by authorized entrants and attendants to maintain contact during the entry

3.5. Gas Purging:

Gas purging must be considered by the safety officer if monitoring or testing has identified the presence of flammable or toxic gases or vapors. If flammable gases are present, this must be done with an inert gas such as nitrogen.
Purging with air can produce a flammable or explosive mixture.

3.6. Ventilation:

Ventilation must be considered where the nature of the confined space dictates that fresh air is required to replenish the oxygen being consumed by the crews. Forced ventilation is preferable.

3.7. Lockout & Tagout:

Specific practices and procedures to safeguard employees from the unexpected energization or startup of machinery and equipment, or the release of hazardous energy during service or maintenance activities.

3.8. Communication:

An effective means of communication between employees inside a confined space and the safety attendant must be used whenever conditions in the space require use of respirators or whenever entrants are out of sight of the safety attendant at any time.

3.9. Personal Protective Equipment:

1. Safety Helmet
2. Safety Goggles
3. Body Harness
4. Coveralls
5. Air Purifying Respirator
6. Self-Contained Breathing Apparatus
7. Safety Shoes
8. Gloves
9. Earplugs

3.10. Breathing Apparatus Entry Control Board:

The BA Control Board shows each firefighter’s tally, with the firefighter’s name, set number, cylinder pressure, and time in.
This enables the BA Controller to work out how long each firefighter can remain on scene tackling the fire before being relieved by another crewmember, ensuring a continued attack on the fire.

3.11. Supervision:

3.11.1. Attendant:

An individual stationed outside one or more permit spaces who monitors authorized entrants and performs all attendant’s duties assigned in the permit space program.

1. Continuously maintains an accurate count of authorized entrants.
2. Communicates with authorized entrants.
3. Performs no duties that might interfere with the primary duty to monitor and protect authorized entrants.

3.11.2. Authorized Entrant:

Employee authorized by employer to enter permit space

1. Communicate with attendant
2. Alert attendant whenever:
   a. Entrant recognizes any warning sign or symptom of exposure to a dangerous situation
   b. Entrant detects a prohibited condition
   c. Exit from permit space as quickly as possible

3.11.3. Entry Supervisor:

A person (such as employer, foreman, or crew chief) responsible for determining if acceptable entry conditions are present at the permit space where entry is planned, authorizing entry, overseeing entry operations, and terminating entry.

1. Knows hazards that may be faced during entry, including information on mode, signs or symptoms, and consequences of exposure
2. Verifies that rescue services are available
3. Removes unauthorized individuals who enter or attempt to enter the permit space during entry operations

3.11.4. Rescue Service Personnel:

Rescue Service Personnel are capable of responding to any emergency.

• This person shall get training of authorized Entrant.

• Employer must provide proper PPEs to Rescue Service Personnel.
• Rescuer must be trained for First Aid & CPR

4. WISER Application