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 are inside the confined space and sometimes a hazardous atmosphere is created by the work activities in the confined space.
The traditional hazard control methods found in regular worksites can be effective in a confined space. These include engineering controls, administrative controls and personal protective equipment. Engineering controls are designed to remove the hazard while administrative 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 hazard, special precautions not normally required in a regular worksite may also need to be taken. The engineering control commonly used in confined spaces is mechanical ventilation. The Entry Permit system is an example of an administrative control used in confined spaces.
Personal protective equipment respirators, gloves, ear plugs is commonly used in confined spaces as well. However, wearing of PPE sometimes may increase heat and loss of mobility. Those situations should be carefully evaluated. Natural ventilation natural air currents is usually not reliable and not sufficient to maintain the air quality.
Mechanical ventilation blowers, fans is usually necessary to maintain air quality. Work where a flame is used or a source of ignition may be produced hot work should not normally be performed in a confined space unless:. In special cases it may not be possible, and additional precautions must be taken to ensure the safety of the worker prior to entering the confined space.
If potential flammable atmosphere hazards are identified during the initial testing, the air in the confined space should be cleaned or purged, ventilated and then tested again before entry to the confined space is allowed. Only after the air testing is within allowable limits should entry occur as the gases used for purging can also be extremely hazardous. All potentially hazardous energy sources such as electrical, mechanical, hydraulic, pneumatic, chemical, or thermal must be de-energized or isolated and locked out prior to entry to the confined space so that equipment cannot be turned on accidentally.
If lock out is not possible, the hazardous energy must be controlled in a way that eliminates or minimizes worker exposure to the hazards before workers are allowed to enter the confined space. It is important that any method of control other than isolation and lockout must be evaluated and the effectiveness for controlling the hazardous energy must be demonstrated.
Many other situations or hazards may be present in a confined space. Be sure that all hazards are controlled, for example:.
Add a badge to your website or intranet so your workers can quickly find answers to their health and safety questions. Although every effort is made to ensure the accuracy, currency and completeness of the information, CCOHS does not guarantee, warrant, represent or undertake that the information provided is correct, accurate or current.
CCOHS is not liable for any loss, claim, or demand arising directly or indirectly from any use or reliance upon the information. OSH Answers Fact Sheets Easy-to-read, question-and-answer fact sheets covering a wide range of workplace health and safety topics, from hazards to diseases to ergonomics to workplace promotion.
Search all fact sheets: Search. Type a word, a phrase, or ask a question. Does the Confined Spaces Regulation apply to spaces that cannot be entered due to their size? Human Occupancy To determine if a space is designed and constructed for human occupancy, one must look at the intent and construction of the space - what is the purpose of the space, or in other words, what was it intended for, and to what standards has it been designed and constructed to allow people to occupy it?
Some examples of spaces that would not be considered as "both designed and constructed for continuous human occupancy" are: storage tanks, tank cars, process vessels, boilers, pressure vessels, vats, bins, silos, bag-houses and other tank like compartments usually having only a manhole for entry open topped spaces such as pump wells, augured caissons, pits or degreasers pipes, sewers, ducts and similar structures cargo tanks, cellular double bottom tanks, duct keels, ballast and oil tanks and void spaces chutes, mill holes, ore bins, inside of a skip hanging in a shaft, crusher jaws flues, chimneys, ovens or furnaces.
What are examples of spaces that are both designed and constructed for continuous human occupancy? What if I cannot determine if a space is not designed and constructed for human occupancy?
What if the space is so small, such as a six inch pipe? In the definition of a confined space, what is meant by "in which atmospheric hazards may occur"?
The intent of this wording is to ensure that consideration is given to atmospheric hazards that may exist in the space or that may occur due to the following: The construction of the space The location of the space The contents of the space The work being done in the space. What are possible sources of atmospheric hazards? Sources of atmospheric hazards may include: Previous contents of the space. An example would be a tank with a residual amount of organic solvent in it, such as perchloroethylene.
Atmospheric hazards generated from chemical reactions of materials present in the space. An example would be the decomposition of organic materials that would cause the formation of methane, a flammable gas, and hydrogen sulphide, a toxic atmospheric contaminant. Another example would be rusting, or oxidation, within a confined space that would consume oxygen and cause an oxygen deficiency.
Activities performed in or about the space. Examples include welding, which generates welding fumes, and solvent cleaning, which generates solvent vapours. Hazardous contaminants that may inadvertently enter into the space from adjacent processes or locations.
An example would be carbon monoxide from vehicle exhaust entering street manholes or a trench. What is a "flammable gas"? What is a "flammable vapour"? What is a "flammable liquid"?
What is meant by "atmospheric contaminants, including gases, vapours, fumes, dusts or mists that could result in acute health effects that pose an immediate threat to life or interfere with a person's ability to escape unaided from a confined space"? What is the connection between the phrase, "atmospheric contaminants, including gases, vapours, fumes, dusts or mists that could result in acute health effects that pose immediate threat to life or interfere with a person's ability to escape unaided from a confined space" and the phrase, "airborne contaminants with IDLH levels"?
Is the application of confined space provisions triggered by potential exposure to IDLH levels of air contaminants?
What are the hazards of oxygen deficiency or enrichment? Ministry of Labour, Training and Skills Development. Employment Standards. Health and Safety. Labour Relations. These incidents could have been prevented if there was a better awareness of confined space hazards.
Do not be overly constrained by the technicalities of the definition; if it looks like a confined space, treat it like one until the hazards have been fully assessed and the potential for risk has been determined. A PRCS is a space that meets the definition of a confined space above, and has one or more of the following hazardous characteristics:.
Many workplaces contain areas that are considered "confined spaces" because while they are not necessarily designed for people, they are large enough for workers to enter and perform certain jobs. A confined space also has limited or restricted means for entry or exit and is not designed for continuous occupancy. Confined spaces include, but are not limited to, tanks, vessels, silos, storage bins, hoppers, vaults, pits, manholes, tunnels, equipment housings, ductwork, pipelines, etc.
OSHA uses the term "permit-required confined space" permit space to describe a confined space that has one or more of the following characteristics: contains or has the potential to contain a hazardous atmosphere; contains material that has the potential to engulf an entrant; has walls that converge inward or floors that slope downward and taper into a smaller area which could trap or asphyxiate an entrant; or contains any other recognized safety or health hazard, such as unguarded machinery, exposed live wires, or heat stress.
Confined spaces are addressed in specific OSHA standards for general industry, maritime, and construction.
0コメント