……....stay focus

Confined Space

Not designed for continuous employee occupancy Confined space means a space that has any of the following characteristics:– limited openings for

entry and exit;– unfavorable natural

ventilation;– not designed for

continuous worker occupancy.

It includes, but is not limited to, boilers, pressure vessels, cargo holds, cargo tanks, ballast tanks, double bottoms, double hull spaces, fuel oil, lube oil, sewage-tanks, pump-rooms, compressor rooms, cofferdams, void spaces, duct keels, inter-barrier spaces and engine crankcases.– Large enough for an

employee to bodily enter and perform assigned work

– Has limited or restricted means for entry or exit

Assess hazards, including Atmospheric hazards the may exist or be created in the confined space.

Determinate appropriate testing procedure, select and calibrate appropriate testing device.

Test for levels of oxygen, flammable, combustible and explosive agents and toxic substances

Can acceptable atmospheric levels by achieved and maintained, with or without purging and ventilating

Are flammable, Combustible or

Explosive agents Present?

Achieve and maintain acceptable atmospheric

levels. Purge and ventilate if necessary.

Can confined Space be rendered

Inert?

Render inert and monitor

Enter with appropriatePrecautions, respiratory

Protection and equipment

Entry not permitted

Are flammable, Combustible Or Explosive agents

Present?

Enter, test per planAnd maintain records

Is combustible dustAirborne creating a

Hazard of explosion?

Go to Chart 2

NO

YES

A YES

YES

YES

A

NO

NO

NO

YES

FROM CHART 1

Concentration of flammable or explosive gas or vapors <5% LEL

Concentration of oxygen<23%

Concentration of flammableor explosive gas or vapor

<10% LEL

Concentration of flammable orExplosive gas or vapor

HOT WORK NOTPERMITTE

COLD WORK NOTPERMITTE

ENTRY NOTPERMITTE

NO

YES

NO

NO

NOHOT WORKPERMITTE

COLD WORK PERMITTE

INSPECTIONPERMITTEYES

YES

YES

CONFINED SPACE AWARENESS

• Data from the Bureau of Labor Statistics indicate an average of 96 fatalities occurred annually between 1992 and 2002, due to oxygen deficient atmospheres. Confined spaces are primary locations where oxygen deficient and sometimes toxic atmospheres develop. Information published by the National Institute for Occupational Safety and Health (NIOSH) indicates more than 60% of confined space fatalities occur among would-be rescuers. The following is provided to prevent injuries and fatalities.

Permit-required Confined Space

• Contains or has the potential to contain a hazardous atmosphere Contains a material that has the potential to overpower an entrant Has an internal configuration that can trap an entrant, asphyxiated by inwardly converging walls or by a floor that slopes downward and narrows to a small cross-section Contains any other recognized safety or health hazard

Non-permit Confined Space

•Does not contain atmospheric hazards, or has the potential to contain any hazard capable of causing death or serious harm (Note: Can become permit space if hazards are brought into it)

Confined Space Awareness at Campus Locations & Field Research Centers

• Atmospheric confined space hazards include those due to oxygen deficiency or the presence of toxic or flammable/explosive gases

• Physical confined space hazards include those associated with mechanical or electrical energy, temperature, engulfment, falling objects, and possibility of drowning

• Examples of permit-required confined spaces include sewers, septic tanks, water tanks, unventilated vaults, hoppers/ silos, and ventilation plenums with fan motor/ blades

• Examples of non-permit confined spaces include storm drains, ventilated vaults, concrete standpipes, attic/ basement crawl spaces, storage containers, and irrigation/ pump sumps

Confined Space Entry & Rescue

• Only authorized and trained employees can participate in a permit-required entry

• On-site rescue capabilities must be planned and in place before permit-required entry

CONFINED SPACES

INTRODUCTION/DEFINITION

Many different places require welding, cutting, and heating work. Some of these places lack room and become “confined spaces.” Confined spaces have the following characteristics:– Limited space, entry, or exit.– Poor ventilation—lack of safe breathing air

and possible buildup of hazardous gases, fumes, and particles.

EXAMPLES OF CONFINED SPACES

• Small rooms.• Storage tanks.• Process vessels. • Pipelines.• Pits • Sewers.• Tunnels. • Silos.• Vats. • Degreasers• Reactor vessels. • Boilers• Underground utility vaults. • Compartments of ships.• Unventilated corners of a room. • Ventilation and exhaust ducts.• Furnaces

REASONS FOR DEATHS AND SERIOUS INJURIES FROM WELDING IN CONFINED SPACES

• Fire.

• Explosion.

• Electric shock.

• Asphyxiation.

• Exposure to hazardous air contaminants.

ACTIONS REQUIRED BEFORE APPROVING START OF WORK IN A CONFINED SPACE

CONFINED SPACES

• Fact Sheet No. 11—9/95 Page 1 of 3• Test confined space atmosphere for (1) suitable oxygen content,

(2) no combustibles or reactive, (3) no toxics.• Note: The testing requires special equipment and training. solate

lines by capping or double valving and venting, if feasible—keep vents open and valves leak-free.

• Lock out all systems not required during welding, cutting, or heating.

• Provide means for readily turning off power, gas, and other supplies from outside the confined space.

• Protect or remove any hazardous materials or materials which may become a physical or health risk when heated or exposed to an arc

REQUIRED ACTIONS DURING WORK IN A CONFINED SPACE

• Continuously ventilate and monitor confined space to ensure that fumes and gases do not exceed safe exposure limits as found in OSHA (Occupational Safety and

• Health Administration) regulations Title 29, CFR Part 1910, 1000.• Use NIOSH/MSHA (National Institute for Occupational Safety and

Health/Mine Safety and Health Administration) approved breathing device when required by code, instruction, or good practice.

• Keep unnecessary persons and equipment out of and away from the confined space.

• Do not allow equipment to block exit or possible rescue efforts.• Place as much equipment as possible outside the confined space.• Do not go into a confined space unless a watchperson, properly equipped

and trained for rescue, is outside and maintaining continuous communications with worker inside.

• Provide means for turning off power, gases, and fuel from inside the confined space, if feasible, especially if outside turn-off means are not provided, feasible, or certain.

Classification of a Confined SpaceHow Can You Identify a Confined Space?

• NIOSH defines a confined space as one that, by design, has limited openings for entry and exit, unfavorable natural ventilation that could contain or produce dangerous air contaminants, and is not intended for continuous employee occupancy.

• Confined spaces include but are not limited to storage tanks, compartments of ships, process vessels, pits, silos, vats, wells, sewers, digesters, degreasers, reaction vessels, boilers, ventilation and exhaust ducts, tunnels, underground utility vaults, and pipelines.

• Confined spaces can be found in many industrial settings, from steel mills to paper mills, from shipyards to farms, and from public utilities to the construction industry. The hazards associated with confined spaces can cause serious injury and death to workers. Two major factors lead to fatal injuries in confined spaces: – (1) failure to recognize and control the hazards associated with

confined spaces and – (2) inadequate or incorrect emergency response. The emergency

response is usually a spontaneous reaction to an emergency situation and can lead to multiple fatalities.

Examples of Confined Spaces

DIGESTER

MANHOLE

PIPELINE

STORAGE TANKSILO

Confined spaces may be classified into two categories:

– (1) open-topped enclosures with depths that restrict the natural movement of air (e.g., degreasers, pits, selected types of tanks and excavations), and

– (2) enclosures with limited openings for entry and exit (e.g., sewers, tanks and silo).

• The hazards found in any confined space are determined by the material being stored or used, by the process taking place inside the space, and by the effects of the external environment. Worker entry into confined spaces may occur during construction activities or during frequent necessary functions such as inspection, repair or maintenance. For purpose of discussion, hazards in confined spaces are separated into atmospheric hazards and physical hazards.

• A confined space: has limited or restricted means of entry or exit is large enough for an employee to enter and perform assigned work is not designed for continuous occupancy

• The hazards found in any confined space are determined by the material being stored or used, by the process taking place inside the space, and by the effects of the external environment. Worker entry into confined spaces may occur during construction activities or during frequent necessary functions such as inspection, repair or maintenance. For purpose of discussion, hazards in confined spaces are separated into atmospheric hazards and physical hazards.

A confined space:– has limited or restricted means of entry or exit– is large enough for an employee to enter and perform assigned work– is not designed for continuous occupancy

Limited Openings for Entry and Exit

Confined space openings are limited primarily by size or location. Openings are usually small in size, perhaps as small as 18 inches in diameter. An access door or portal that is too small to allow an employee to walk upright and unimpeded through it is considered to be limited access or exit. These small openings may make it very difficult to get needed equipment in or out of the spaces.

Not Designed for Continuous Worker Occupancy

• Most confined spaces are not designed for workers to enter and work in them on a routine basis. They are designed to store a product, to enclose materials and processes, or to transport products or substances. The distance an employee must travel in a space such as a tunnel to reach a point of safety can be a determinant for classifying as space as a confined space. Therefore, occasional worker entry for inspection, maintenance, repair, cleanup or similar tasks is often difficult and dangerous due to chemical, distance or physical hazards within the space.

• A confined space found in the workplace may have a combination of the above characteristics, which can complicate working in and around these spaces, as well as hamper rescue operations during emergencies. If a survey of your working area identifies one or more work spaces with the characteristics listed above, then please read the following information— someday it may save your life or the life of a co-worker.

How Can You Identify a Permit-Required Confined Space?

• A permit-required confined space is one that meets the definition of a confined space and has one or more of these characteristics:

contains or has a potential to contain a hazardous atmosphere contains a material that has the potential for engulfing an entrant has an internal configuration such that an entrant could be trapped or asphyxiated by inwardly converging walls or by a floor which slopes downward and tapers to a smaller cross-section contains any other recognized serious safety or health hazard immediately dangerous to life and health that prevents self-rescue

What Are the Hazards Involved in Entering

and Working in Confined Spaces?

• Many workplaces contain spaces configured is such a way to be considered “confined.” Confinement itself may pose entrapment hazards. Working in a confined space may keep employees closer to hazards. For example, confinement, limited access or restricted airflow can result in hazardous conditions that would not arise in an open workplace.

Hazardous Atmospheres• Many substances have short-term exposure

limits, in addition to 8-hour time weighted average exposure limits. The permit required confined space rule is intended to protect against short-term acute hazards. Exposures at or below the permissible exposure limits do not fall under the permit-required confined space rule. Other standards (see 29 CFR 1910, Subparts G and Z) address a broader range of health and safety concerns. Any substance that is not capable of causing death, incapacitation, impairment of ability to self-rescue, injury or acute illness due to health effects is not covered by the rule.

• The atmosphere in a confined space may be extremely hazardous because of the lack of natural air movement. This characteristic of confined spaces can result in: – (1) oxygen-deficient– (2) flammable – (3) toxic atmospheres.

Oxygen-Deficient Atmospheres• An oxygen-deficient atmosphere has less than

19.5 percent available oxygen (O2). When oxygen levels drop below 17 percent, there is increased breathing volume, accelerated heartbeat and a deterioration of night vision, which is usually not noticeable. Oxygen atmospheres with 14 to 16 percent oxygen contribute to poor muscular coordination, rapid fatigue and intermittent respiration. At 6 percent oxygen, there is a rapid loss of consciousness and death in minutes.

• Any atmosphere with less than 19.5 percent oxygen should NOT be entered without a NIOSH-approved self-contained breathing apparatus or a NIOSH-approved supplied air breathing apparatus.

• The oxygen level in a confined space can decrease because of the type of work being done, such as welding, cutting or brazing, or it can be decreased by certain chemical reactions (rusting) or through bacterial action (fermentation).

• The oxygen level is also decreased if oxygen is displaced by another gas, such as carbon dioxide, argon, helium or nitrogen. Total displacement of oxygen by another gas, such as carbon dioxide, will result in unconsciousness, followed by death.

OXYGEN SCALE

23.50%       O2 Enriched

   

   

   

   

19.50%         Minimum for

    safe entry

   

   

16%         Impaired judgment

    and Breathing

14%         Faulty judgment

    rapid fatigue

   

   

   

   

   

   

6%         Difficult breathing

    death in minutes

   

   

   

   

         

Flammable Atmospheres• Flammable atmospheres generally result from

evaporation of flammable liquids, by-products of chemical reactions, enriched atmospheres or concentrations of combustible dusts. Two things make an atmosphere flammable:

– (1) the amount of oxygen in air and– (2) a flammable gas, vapor or dust in the proper mixture.

• Different gases and combustible dusts have different flammable and explosive ranges. (See National Fire Protection Association publication 497-1997, Classification of Flammable Liquids, Gases, or Vapors and of Hazardous (Classified) Locations for Electrical Installations in Chemical

• Process Area, and National Fire Protection Association publication 499-1997, Recommended Practices for Classification of Combustible Dusts and of Hazardous (Classified) Locations for Electrical Installation in Chemical Process). When a source of ignition (for example, a sparking or electrical tool) is introduced into a space containing a flammable atmosphere, a fire or an explosion can result.

• An oxygen-enriched atmosphere (above 23.5 percent) will cause flammable materials, such as clothing and hair, to burn violently when ignited and may cause some nonflammable materials to ignite. Therefore, NEVER use pure oxygen to ventilate a confined space. Ventilate with normal air.

THE IGNITION TRIANGLE

GAS, VAPOR OR DUST

SOURCE OF IGNITION

AIR

FLAMMABLE ATMOSPHERE

Toxic Atmospheres

Toxic atmospheres can be caused by the following:The product stored in the space. The product may contain a toxic component, which could b absorbed into the walls and have the

potential for release depending on the use of the space.The type of work being performed in a confined space. Examples of such include welding, cutting, brazing, painting, scraping,

sanding and degreasing. Toxic atmospheres are generated in various processes. For example, cleaning solvents are used in many industries for cleaning/degreasing. The vapors from these solvents can build up to toxic levels in a confined space.

Areas adjacent to the confined space. Toxicant produced by work near confined spaces can enter and accumulate in confined spaces. (Figure 4 illustrates work that may go on in confined spaces.)

Because air cannot freely move in and out of confined spaces due to the design and configuration, the atmosphere inside a confined space can be very different from the atmosphere outside. Deadly gases may be trapped inside, particularly if the space is used to store or process chemicals or organic substances that may decompose. There may not be enough oxygen inside the confined space to support life, or the air could be so oxygen-rich that it is likely to increase the chance of fire or explosion if a source of ignition is present.

General/Physical HazardsIn addition to the areas discussed above, evaluation of a confined space

should consider the following potential hazards:

Temperature Extremes– Extremely hot or cold temperatures can present problems for workers. For

example, when possible, a steam tunnel should be allowed to cool before entering.

Engulfment Hazards– Loose granular material stored in bins and hoppers, such as grain, sand,

coal or similar material, can engulf and suffocate a worker. The loose material can crust over, or bridge over, in a bin and break loose under the weight of a worker.

The Hazard of Engulfment in Unstable Material

Noise• Noise within a confined space can be amplified because of the design and acoustic properties of the

space. Excessive noise can not only damage hearing and reduce reaction time to hazards but can also affect communication. This can cause a shouted warning to go unheard.

Slick/Wet Surfaces• Slips and falls can occur on a wet surface, causing injury or death to workers. Spaces that have an

internal configuration, inwardly converging walls, or a floor that slopes downward and tapers to a smaller cross-section, increase the hazards of slipping and falling. Different material contained in the space may react differently in a wet environment. A wet surface will also increase the likelihood for and effect of electric shock in areas where electrical circuits, equipment and tools are used.

Falling Objects• Workers in confined spaces should be mindful of the possibility of falling objects, particularly in spaces

that have topside openings for entry and where work is being done above the worker

General HazardsWork in confined and enclosed space has a greater likelihood of causing

fatalities, severe injuries and illness than any other type of shipyard work or onboard ships.

• The key hazards associated with confined spaces are:— serious risk of fire or explosion;— loss of consciousness from asphyxiation arising from gas,

fumes, vapor or lack of oxygen;— drowning arising from increased water level;— loss of consciousness arising from an increase in body

temperature;— asphyxiation/suffocation arising from free flowing solid

(engulfment) or the inability to reach a breathable atmosphere due to entrapment.

• Surveyors will routinely enter confined spaces that are difficult to access due to small and/or narrow openings. There may be physical constraints within the space which need to be considered, and the space itself may be cramped permitting only restricted mobility.

• Given the usual enclosed and darkened nature of a confined space this activity ideally should not be carried out by personnel suffering from phobias (e.g. claustrophobia) or who are susceptible to panic or anxiety attacks.

General HazardsRecognition of the inherent capacity of these spaces to harbor

hazardous agents is a significant element in any workplace hazard assessment. When confined spaces are recognized to be hazardous, provisions for minimizing the need for entry and for use of appropriate work practices and equipment can be made.

Access to open-topped spaces may require the use of ladders, hoists or other devices. Escape from such areas may be very difficult in emergency situations. Ladders and temporary, movable, spiral or articulated stairs are usually considered limited or restricted means of egress. Fixed industrial stairs that meet OSHA standards must be considered limited or restricted means of egress when the conditions or physical characteristics of the space, in light of the hazards present in it, would interfere with the entrant’s ability to exit or be rescued in a hazardous condition.

A space has limited or restricted means of entry or exit if an entrant’s ability to escape in an emergency would be hindered.

Two workers die from lack of oxygen in confined space

• Two workers were repairing a process vessel at a pulp mill. The valves to the vessel were locked out, but a nitrogen supply to the power boiler was not locked out because it had not been identified in the lockout procedures. Nitrogen gas inadvertently leaked from the boiler system into lines that fed into the process vessel, displacing the oxygen and creating an IDLH (immediately dangerous to life or health) atmosphere.

• The vessel was a confined space. Appropriate confined space entry procedures to the vessel had been followed on previous entries. However, on this re-entry, the atmosphere was not tested and the space was not ventilated. One worker entered the vessel and collapsed from oxygen deficiency. The second worker, who had been watching outside the entrance hole, was found collapsed with his head inside the vessel.

Safe work practices• Consider each entry to a confined

space to be potentially deadly. Proper testing and safe entry procedures must be followed for each entry.

• Identify and label confined spaces in the workplace.

• Provide written safe work procedures for entering a confined space and ensure that workers are trained in these procedures.

• Isolate the confined space from adjacent piping by blanking, blinding, or disconnecting the piping.

• Assess the hazards before entering a confined space, including testing for oxygen levels if necessary.

Note: This hazard alert is based on an accident that occurred in 1997.

THE SILENT DANGERS OF CONFINED SPACE

• Workers tend to put their faith in most indoor or confined atmospheres, thinking someone else has checked for safety. Air, whether life sustaining or killing, is usually colorless, odorless, and tasteless. The atmosphere in a confined space, for example, may seem like any other. But that is one work place that must never be taken for granted. Confined spaces have fooled scores of workers killed or injured every year because they thought someone had checked for safety or because they “followed their noses” and guessed the air smelled OK. The air may look safe and smell safe, yet be filled with enough toxic contaminants to kill.