CONFINED SPACE – HAZARDS –RISK –CONTROL MEASURES

1. CONFINED SPACE
Confined spaces can include: tanks, silos, pits, trenches, vaults, pipelines, manholes, digester, as
well as many other restrictive spaces that qualify as well. A “Confined Space” is defined as a
space which has any one of the following characteristics:
• Limited openings for entry and exit
• Unfavorable natural ventilation
• Not designed for continuous worker occupancy
Hazardous atmospheres in confined spaces present one of the greatest dangers to workers.
Oxygen deficient atmospheres have less than
atmosphere with less than 19.5% oxygen without an approved, self
apparatus. Flammable atmospheres contain two things that make them flammable: oxygen and
a flammable gas, vapor or dust in
confined space, or in adjacent areas can create toxic atmospheres. Ventilate with a blower or
fan to remove harmful gases and vapors if necessary. The atmosphere of any confined space
should be tested by a competent person before each shift or before any worker enters the
space. Any power sources in the confines space, which could present a hazard should be
isolated and locked out. You may need to lock out electrical power, bland and bleed pneuma
and hydraulic lines, disconnect belt and chain drives and mechanical linkages on shaft
equipment, and secure mechanical moving parts within the confined space with latches, chains,
chocks, blocks or other devices.
A standby person should be assigned to remain on the outside of the confined space and be in
contact with the workers inside, either visually or verbally. The standby person should not have
any other responsibilities and be able to call for immediate assistance in case of an emergency.
The hazards associated confined spaces include:
• Toxic Atmosphere. A toxic atmosphere may cause various acute effects, including
impairment of judgment, unconsciousness and death. ...
• Oxygen Deficiency. ...
• Oxygen Enrichment. ...
• Flammable or Explosive Atmospheres. ...
• Following Liquid or Free Flowing Solids. ...
• Excessive Heat.
Risk Assessment of Confined Space
When carrying out a risk assessment it is important to ensure that all risks associated with the
hazards above are evaluated and controlled.
questions should be asked:
CONFINED SPACE – HAZARDS –RISK –CONTROL MEASURES
Confined spaces can include: tanks, silos, pits, trenches, vaults, pipelines, manholes, digester, as
well as many other restrictive spaces that qualify as well. A “Confined Space” is defined as a
space which has any one of the following characteristics:
• Limited openings for entry and exit
• Unfavorable natural ventilation
• Not designed for continuous worker occupancy
Hazardous atmospheres in confined spaces present one of the greatest dangers to workers.
Oxygen deficient atmospheres have less than 19.5% available oxygen. You should not enter an
atmosphere with less than 19.5% oxygen without an approved, self-contained breathing
apparatus. Flammable atmospheres contain two things that make them flammable: oxygen and
a flammable gas, vapor or dust in the proper combination. Toxic materials stored or used in the
confined space, or in adjacent areas can create toxic atmospheres. Ventilate with a blower or
fan to remove harmful gases and vapors if necessary. The atmosphere of any confined space
tested by a competent person before each shift or before any worker enters the
space. Any power sources in the confines space, which could present a hazard should be
isolated and locked out. You may need to lock out electrical power, bland and bleed pneuma
and hydraulic lines, disconnect belt and chain drives and mechanical linkages on shaft
equipment, and secure mechanical moving parts within the confined space with latches, chains,
igned to remain on the outside of the confined space and be in
contact with the workers inside, either visually or verbally. The standby person should not have
any other responsibilities and be able to call for immediate assistance in case of an emergency.
The hazards associated confined spaces include:
Toxic Atmosphere. A toxic atmosphere may cause various acute effects, including
impairment of judgment, unconsciousness and death. ...
tmospheres. ...
Following Liquid or Free Flowing Solids. ...
Risk Assessment of Confined Space
When carrying out a risk assessment it is important to ensure that all risks associated with the
hazards above are evaluated and controlled. When carrying out a risk assessment the following
Confined spaces can include: tanks, silos, pits, trenches, vaults, pipelines, manholes, digester, as
well as many other restrictive spaces that qualify as well. A “Confined Space” is defined as a
Hazardous atmospheres in confined spaces present one of the greatest dangers to workers.
19.5% available oxygen. You should not enter an
contained breathing
apparatus. Flammable atmospheres contain two things that make them flammable: oxygen and
the proper combination. Toxic materials stored or used in the
confined space, or in adjacent areas can create toxic atmospheres. Ventilate with a blower or
fan to remove harmful gases and vapors if necessary. The atmosphere of any confined space
tested by a competent person before each shift or before any worker enters the
space. Any power sources in the confines space, which could present a hazard should be
isolated and locked out. You may need to lock out electrical power, bland and bleed pneumatic
and hydraulic lines, disconnect belt and chain drives and mechanical linkages on shaft-driven
equipment, and secure mechanical moving parts within the confined space with latches, chains,
igned to remain on the outside of the confined space and be in
contact with the workers inside, either visually or verbally. The standby person should not have
any other responsibilities and be able to call for immediate assistance in case of an emergency.
Toxic Atmosphere. A toxic atmosphere may cause various acute effects, including
When carrying out a risk assessment it is important to ensure that all risks associated with the
When carrying out a risk assessment the following

2. • What could be inside the space that would pose a risk?
- Contents?
- Oxygen Deficiency?
- Previous Contents?
- Oxygen Enrichment?
- Residues?
- Structure and Layout?
- Contamination?
• What will be created due to the work carried out in the space?
- Sources of Ignition?
- Flammable Substances?
• What‘s outside the space that might pose a risk during the prop
- Inadequate Isolation?
- Inadvertent Operation of Plant?
- Nearby Work Activities?
Safe system of work for a confined space
The key elements to be considered when drawing up a safe system of work are:
• Competence, training, supervision
• Permit-to-work procedure
• Gas purging and ventilation
• Dangerous residues
• Testing and monitoring of the atmosphere
• Mechanical, electrical and process isolation
• Respiratory protective equipment
• Other personal protective equipment
• Safe use of work equipment
• Communications
• Access and egress
• Flammable or explosive atmospheres
• Combustible materials
Permit-to-work procedure.
A permit to work procedure is a means of achieving effective control of a system of work
through formal written documentation
components of a permit-to-work system include:
• A written procedure, which sets out how the system is to operate and clearly defines
who may authorize particular jobs and who is responsible for specifying and
implementing the necessary precautions
• A form, known as the "permit
statement ensuring both the establishment of safe conditions for the work to
What could be inside the space that would pose a risk?
Structure and Layout?
What will be created due to the work carried out in the space?
Flammable Substances?
What‘s outside the space that might pose a risk during the proposed work?
Inadvertent Operation of Plant?
Nearby Work Activities?
Safe system of work for a confined space
The key elements to be considered when drawing up a safe system of work are:
Competence, training, supervision and suitability
work procedure
Gas purging and ventilation
Testing and monitoring of the atmosphere
Mechanical, electrical and process isolation
Respiratory protective equipment
Other personal protective equipment
work equipment
Flammable or explosive atmospheres
A permit to work procedure is a means of achieving effective control of a system of work
through formal written documentation known as a permit to work form. The essential
work system include:
A written procedure, which sets out how the system is to operate and clearly defines
who may authorize particular jobs and who is responsible for specifying and
implementing the necessary precautions
A form, known as the "permit-to-work form", which becomes a written and signed
statement ensuring both the establishment of safe conditions for the work to
osed work?
The key elements to be considered when drawing up a safe system of work are:
A permit to work procedure is a means of achieving effective control of a system of work
The essential
A written procedure, which sets out how the system is to operate and clearly defines
who may authorize particular jobs and who is responsible for specifying and
work form", which becomes a written and signed
statement ensuring both the establishment of safe conditions for the work to

3. commence and the maintenance of safe conditions for the durat
including the provision of emergency arrangements
• A method of informing the persons carrying out the work of the exact identity, location,
nature and extent of the job, the hazards involved and the precautions to be taken, and
• A system for ensuring the safe hand
and, in the case of confined space entry, after the space is vacated
commence and the maintenance of safe conditions for the duration of the work,
including the provision of emergency arrangements
A method of informing the persons carrying out the work of the exact identity, location,
nature and extent of the job, the hazards involved and the precautions to be taken, and
ensuring the safe hand-back of the workplace after the job is completed
and, in the case of confined space entry, after the space is vacated
ion of the work,
A method of informing the persons carrying out the work of the exact identity, location,
nature and extent of the job, the hazards involved and the precautions to be taken, and
back of the workplace after the job is completed