confined space

Construction Standards for Confined Space Entry

Construction standards for confined space entry have been defined and set for enforcement by the Occupational Safety and Health Administration (OSHA). These standards are now specifically for the construction industry. The previous regulations only applied to general industry. Still others are covered under the American National Standard ANSI Z117.1-1989, Safety Requirements for Confined Spaces.

Construction Standards Expanded from Existing Regulations

OSHA General Industry regulation 1910.146, permit-required confined spaces, details the practices and procedures for safe entry for work in a permit-required confined space. This regulation does not specifically apply construction work.

OSHA regulation 1926 applies to construction safety and health. It does address some construction standards for a permit-required space regulation. The following portions of 1926 apply to confined space entry in construction work:

Sub-part C – 1926.21 Safety training and education covers the requirements for safety training prior to entering and working in a confined space. It defines a confined space as “any space having a limited means of egress, which is subject to the accumulation of toxic or flammable contaminants or has an oxygen deficient atmosphere.”.

Sub-part S – 1926.8 applies to the construction of underground tunnels, chambers, and passageways. It also includes cut-and-cover excavations that are connected to underground construction operations. These are covered in a manner that creates conditions characteristic of underground construction.

1926.956 covers underground electric transmission and distribution work. It includes guarding and ventilating street openings used for access to underground lines or equipment. 1926.956(a) applies to trenching and excavating. 1926.956(c), other related operations.

1926 Sub-part P contains additional requirements for confined space entry applying specifically to excavations.

1926 Sub-part J applies to welding and cutting in confined spaces.It includes requirements for ventilation and protection while welding, cutting, and heating plus other confined space related regulations.

Finally, a new standard recently adopted, OSHA 29 CFR 1926 Sub-part AA, now specifically defines construction standards for permit-controlled confined spaces and is set for enforcement. After years of feedback and analysis, OSHA felt that an updated, specific standard was necessary to more thoroughly handle the construction industry.

Other general construction standards guidelines which are applied to confined space work beyond OSHA regulations are found in American National Standard ANSI Z117.1-1989. These are Safety Requirements for Confined Spaces which provide minimum safety requirements for entering, exiting, and working in confined spaces at normal atmospheric pressure.

Identifying Confined Space Hazards in Construction Work

Identifying confined space hazards is very important for almost all construction sites. The confined space entry standards as defined by OSHA, for General Industry and Construction are actively enforced by OSHA. There’s good reason. Confined space incidents have risen in both industries, but is amplified in Construction. Proper training, consistent inspection, documentation and preparation of a safety and rescue plan all are required under OSHA 29 CFR 1910.146 and OSHA 29 CFR 1910.146 Subpart AA.

Identifying Confined Space Hazards as Inherent or Induced Hazards

There are two types of hazards encountered in confined work spaces – inherent and induced. Inherent hazards are related to equipment and the interactions of working with them. Identifying inherent confined space hazards is based around the observation of operations and include hazards such as:

shock or burn from high voltage electrical equipment
exposure to radiation generated by certain equipment
defectively designed equipment
lack of protective features such as grounding for non-current-carrying conductive parts
high or low temperatures
high noise levels
high-pressure equipment that may rupture.
Inherent hazards cannot be eliminated from the equipment without affecting their operation, so these hazards must be used employing hazard control methods.

Induced hazards are those caused by incorrect decisions or actions during the construction process. Identifying confined space entry hazards involvingf induced hazards include:

physical arrangements that might cause accidental contact by a worker with electrical energy sources
lack of oxygen in areas like the bottom of pits or shafts
omission of protective features
lack of safe structural strength of the workspace
flammable atmospheres such as those where volatile gases may be present.

Identifying confined space hazards may involve both inherent and induced hazards. Examples of such hazardous environments include:

Vaults in which the atmosphere may be or become oxygen-deficient.
Electrical vaults which may become filled with explosive gases such as from propane, or toxic fumes that can build-up in a limited atmosphere from welding and soldering in a confined space.
Electrical shock can occur when working in any confined space with power tools, line cords, and similar equipment, where the contractor has not provided an approved grounding system, ground-fault circuit interrupters, or low-voltage systems.
In a workspace where purging agents such as nitrogen or argon are being used in an adjacent area, the fumes may displace the oxygen in a vault to the point where workers could suffer immediate asphyxiation.
Condenser pits are a type of confined space encountered during the construction of nuclear power plants which are fairly large, so that the potential for the hazards associated with a confined workspace may be overlooked. Toxic fumes and gases can accumulate in these areas from the use of argon, freon, and other inert gases, creating oxygen-deficient atmospheres for workers. Another hazard in this type of workspace is caused by workers above accidentally dropping equipment, tools, or other materials into the pit.
Pipe assemblies are another type of confined space common in construction. Identifying confined space hazards of this type, can involve other types of work spaces, such as oxygen-deficient atmospheres caused by purging with argon or other inert gases. They may contain ungrounded electrical equipment, also. They can also be very restricted spaces where there is little room for workers to move around or find a comfortable position to perform their work. Also, where bends occur in pipes communication can be cut off, and getting a worker out of the area can be extremely difficult. The heat within a pipe may cause workers to suffer heat prostration, as well.
The same types of hazards are encountered working within ventilation ducts as within pipes. Identifying confined space hazards in narrow spaces are characterized by many bends restricting movement and communication, They can contain toxic or oxygen-deficient atmospheres. In some cases electrical shock, and extreme heat all can occur within this type of space.
Tanks used for storage of water, chemicals, or other materials often require entry for cleaning or repairs. Identifying confined space hazards in these spaces can include heat, oxygen-deficient atmospheres and electrical shock. They may also contain fall hazards from climbing high ladders on the walls of a tank.
Manholes are common on construction sites. Manhole covers are sometimes removed and not replaced, or not provided at all, making it a dangerous trap where a worker may fall. Identifying confined space hazards here can many time can be easily fixed.

Other hazardous confined work spaces include sumps, containment cavities, electrical transformers, and heat sinks, all of which carry the risks of the same inherent and induced hazards associated with the spaces described above. Identifying confined space hazards in these potentially hazardous environments is critical

Awareness of the hazards found in these types of confined entry work spaces is an important step in the prevention of injuries and fatalities caused by these hazards.

Confined Space Danger Fundamentals

Confined space danger in both General Industry and Construction have vaulted into the top tier of attention by OSHA. A confined space is characterized by one that has a hazard to health or life associated with it. Hazards may be the result of atmosphere or materials in the space or the result of the shape of the space. OSHA has provided new standards as well as enhancing existing standards to help in the enforcement.

“We’ve learned enough over the years that there’s no reason that people should be dying in confined spaces,” said Michael Wilson, director of the Labor Occupational Health Program at UC Berkeley’s School of Public Health.

Confined Space Danger Centers Around Asphyxiation and Physical Trauma.

Many workplaces are subject to confined space danger. Confined spaces are designated as such because their configurations hinder the activities of any employees who must enter, work in and then exit them. For instance, areas where employees much squeeze in and out through narrow openings, and perform tasks while cramped or contorted. The major health hazards are asphyxiation and physical trauma.

Asphyxiation is the leading confined space danger. Workers that have died in such accidents found themselves in oxygen deficient atmospheres as a result of exposure to toxic substances. These may include gases or particulates. In several cases, workers were in the confined spaces of water towers or bulk material hoppers and fell into narrow, tapering discharge pipes. This caused died by asphyxiation due to compression of the torso. Many workers each year, working in silos, have been asphyxiated as the result of engulfment in finely divided particulate matter (such as sawdust) that blocks the breathing passages. All of these must be part of a standard safety protocol to educate and protect against these confined space danger situations.

Other documented confined space death incidents include workers that were burned or ground-up by auger type conveyors, or crushed or battered by rotating or moving parts inside mixers. Failure to de-energize equipment inside the space prior to employee entry was a major confined space danger factor in most of those accidents.

The sad fact, is that many employers have under-appreciated the degree to which the conditions of permit space work can compound the risks of exposure to atmospheric or confined space danger scenarios. In addition, the elements of confinement, limited access, and restricted air flow, can result in hazardous conditions which would not arise in an open workplace. For example, vapors which might otherwise be released into the open air can generate a highly toxic or otherwise harmful atmosphere within a confined space. Unfortunately, in many cases, employees have died because employers improvised or followed “traditional methods” rather than following existing OSHA standards, recognized safe industry practice, or common sense.

OSHA has noted that by their very nature and configuration, many permit spaces promote a confined space danger due to hazardous atmosphere situations. Unless adequate precautions are taken, these can be immediately dangerous to life and health. Many confined spaces are poorly ventilated which leads to the creation of an oxygen deficient atmosphere and the accumulation of toxic gases. The failure to take proper precautions for these permit spaces have therefore resulted in fatalities, as opposed to injuries more frequently than would be normally predicted.

To emphasize the point, examine the following statistics from OSHA:
There were 431 confined space incidents with 530 fatalities in the US due to oxygen deficient and/or toxic atmospheres from 1992-2005
From 8/18/2009 – 12/31/2009 there were 36 worker fatalities and 6 worker hospitalizations related to confined spaces
In 2010, there were 63 worker fatalities and 28 hospitalizations related to confined space conditions
From 1/1/2011 to 8/1/2011, there were 22 worker fatalities and 3 worker hospitalizations related to confined spaces.
Repair & Maintenance and cleaning & inspection activities account for almost one quarter of the fatalities.
Construction and manufacturing industries experience the most fatalities

In a subsequent post we’ll examine the various causes of death and injury in detail and discuss how each can be mitigated.