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Confined Space Entry Program

Last Updated: 03/02/2018

The purpose of the Injury Illness Prevention Program (IIPP) is to outline Cal Maritime's environmental health and safety requirements, expectations, and responsibilities in order to achieve effective campus safety performance through Integrated Safety Management (ISM). The Confined Space Entry Program is a subject specific component the supports the overall University IIPP.

Note: Training Ship Golden Bear (TSGB) is regulated under MARAD. For operations pertaining to the TSGB  -  Refer to Shoreside Administration Manual (SAM) and Vessel Operations Manual (VOM).

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Californians die in confined space accidents every year. Not only is the original victim at high risk, but 60 percent of the fatalities are would-be rescuers who enter the space attempting to retrieve the fallen individual(s), only to be overcome by the hazardous atmosphere and perish themselves.

Cal Maritime maintenance and telecommunication employees entering confined spaces on campus may encounter extremely hazardous atmospheric conditions and/or access difficulties, which could become life  threatening. Such locations include sewers, wet-wells, tanks, boilers, crawl spaces, acid pits, vaults, storm drains, pipelines, bins, tubs, ducts and vessels that must be entered for repairs, inspection and maintenance. Insufficient ventilation may allow for the accumulation of toxic or flammable gases or the critical depletion of oxygen necessary to sustain life. Limited access into and out of these spaces also greatly hampers rescue operations.

This Program applies to any activities being conducted in locations by University personnel where confined space hazards that require protection are part of research/work activities.  This includes contract employees and students performing research related activities in field stations and remote facilities.

Hazard Assessment

Entering a confined space is done usually to perform a necessary function, such as inspection, repair, maintenance (cleaning or painting), telecommunications and electrical utility work performed in manholes and unvented vaults, cutting or welding in confined spaces, Work in excavations or trenches that could develop hazardous atmospheres, work in sewers, manholes, pits, traps or similar operations which would be an infrequent or irregular function of the total Maintenance activities.

Entry may also be made during new construction. Potential hazards should be easier to recognize during construction since the confined space has not been used. One of the most difficult entries to control is that of unauthorized entry, especially when there are large numbers of workers and trades involved, such as welders, painters, and electricians.

Confined spaces include tanks, silos, ducts, pipelines, sumps, boilers, casings, sewers, pits, trenches, utility vaults, and similar locations. All need detailed evaluation for entry due to the potential presence of chemical, physical, mechanical, and/or other hazards.

There are two primary classifications of hazards within confined spaces: atmospheric hazards and physical hazards. Atmospheric refers to problems with the air in a space, while physical refers to problems caused by equipment or by other dangerous conditions. It is critical to identify all the hazards in a confined space and determine how they impact the health and safety of workers entering them.

 Atmospheric Hazards

The inefficient or nonexistent ventilation of a confined space can cause the atmosphere in the space to become life threatening. Processes of biological activity, decomposition of natural materials, oxidation, percolation of vapors and structural leaks can cause the production and accumulation of toxic and/or flammable gases. Available oxygen levels may become seriously depleted or displaced through these processes. When the atmosphere becomes contaminated with harmful gases or depleted of oxygen, the exposed worker may not immediately feel the effects. A false feeling of euphoria or well-being is a common side effect to such exposure. A number of these toxic gases have no odor or color detectable by the body's senses. Many who die in confined space accidents simply slip into unconsciousness quietly, never realizing what is happening and never to reawaken.



Chemical Hazards:

Some of the chemical hazards of entering confined spaces include the presence of;

  • Flammable/explosive atmospheres,
  • Toxic/hazardous atmospheres,
  • Asphyxiating atmospheres and
  • Corrosive exposures.



Many of the gases routinely found in confined spaces are flammable or combustible under the right combination of conditions. These gases include hydrogen sulfide, carbon monoxide, acetylene, and methane. When fuel, oxygen, and an ignition source are present at the same time and in the correct proportions, a serious explosion or fire can result. If a combustible gas and air are trapped in a confined space, only a source of ignition is needed to cause an explosion. Welding, sparking tools, smoking, or static electricity can easily provide an ignition source.

The lowest concentration (air-fuel mixture) at which a gas can ignite is called its Lower Explosive Limit (LEL). Concentrations below this level are too lean to burn. The highest concentration that can be ignited is its Upper Explosive Limit (UEL). Above that concentration, the mixture is too rich to burn. A gas is flammable in concentrations between its LEL and UEL.

Monitoring instruments analyze air samples and alarm at a predetermined concentration level, usually 10 percent of the LEL. The worker is then provided with advance warning concerning the potential hazard.

Any concentration of flammable gas is reason for concern in a confined space. Overly rich mixtures can collect in an area and reach combustible concentrations when fresh air is introduced, quickly changing its proportions to levels between the LEL and UEL. Confined space atmospheres containing an enriched oxygen level above 23.5 percent increase the flammability ranges of many gases as well as support violent reactions when ignition occurs. Oils and grease may unexpectedly burst into flames under such atmospheric conditions.



Toxic Gases - There are many different types of toxic gases that can be found in confined spaces. Their sources and physical characteristics vary, but they all share one common thread - potential harm to individuals who enter a hazardous atmosphere in enclosed areas.

There are two categories of toxic gases: irritants and asphyxiates.

  • Irritants - Many gases existing in low concentrations in the air are irritating to the body's respiratory and nervous systems. When inhaled, they cause the mucous linings of the lungs and sinuses to swell, sometimes so severely that the respiratory tract closes, causing strangulation. Except under extreme conditions, the body normally recovers after exposure to toxic gases has been stopped. In higher concentrations, irritants can become asphyxiating gases.
  • Asphyxiates -  An asphyxiate is any gas that, when present in a high enough concentration, causes displacement of oxygen in the body.



Our normal atmosphere is composed approximately of 20.9% oxygen and 78.1% nitrogen, and 1% argon. The consumption of oxygen takes place during combustion of flammable substances, as in welding, heating, cutting, and brazing. A more subtle consumption of oxygen occurs during bacterial action, as in the fermentation process. Oxygen may also be consumed during chemical reactions as in the formation of rust on the exposed surface of the confined space (iron oxide). The ventilation air should not create an additional hazard due to recirculation of contaminants, location of the air inlet duct where airborne contaminants may be introduced, or by the substitution of anything other than fresh air.

The number of people working in a confined space and the amount of their physical activity will also influence the oxygen consumption rate.

Oxygen deficiency can also be caused by displacement by another gas. Examples of gases that are used to displace air, and therefore reduce the oxygen level are helium, argon, and nitrogen. Carbon dioxide may also be used to displace air and can occur naturally in sewers, storage bins, wells, and tunnels.

Gases such as nitrogen, argon, helium, and carbon dioxide, are frequently referred to as non-toxic inert gases but have claimed many lives. The use of nitrogen to inert a confined space has claimed more lives than carbon dioxide. Carbon dioxide and argon, with specific gravities greater than air, may lie in a tank or manhole for hours or days after opening. Since these gases are colorless and odorless, they pose an immediate hazard to health unless appropriate oxygen measurements and ventilation are adequately carried out.

Harmful effects of exposure to varying toxic gases and oxygen levels

Oxygen Depletion - Life ceases quickly without enough oxygen. Common sources of oxygen depletion in confined spaces include aerobic bacterial growth, oxidation/rusting of metals, combustion, and displacement by other gases. Oxygen comprises only a small percentage (20.9 percent) of the air we breathe. When levels of oxygen are reduced below 19.5 percent (the minimum acceptable level), serious health problems begin to occur very quickly.

The following provides an overview of those effects at various oxygen levels:




Maximum permissible oxygen level. No effect


Percentage of oxygen found in normal air. No effect.


Minimum permissible oxygen level. No effect.


Decreased ability to work strenuously. May impair coordination and may induce early symptoms with individuals that have coronary, pulmonary, or circulatory problems.


Respiration and pulse increase; impaired coordination, perception, and judgment occurs.


Respiration further increases in rate and depth; poor judgment and bluish lips occur.


Symptoms include mental failure, fainting, unconsciousness, an ash-colored-face, blue lips, nausea, and vomiting.


8 minutes - 100 percent fatal; 6 minutes - 50 percent fatal; 4-5 minutes - recovery with treatment.


Coma in 40 seconds, convulsions, respiration ceases - death.


Oxygen within a space may be depleted through the displacement of other gasses. Some gases are heavier than air and move downward; others, being lighter than air travel upward, displacing the available oxygen as they fill the space.

Carbon monoxide (CO) is a hazardous gas that may build up in a confined space. This odorless, colorless gas that has approximately the same density as air is formed from incomplete combustion of organic materials such as wood, coal, gas, oil, and gasoline; it can be formed from microbial decomposition of organic matter in sewers, silos, and fermentation tanks. Carbon monoxide is an insidious toxic gas because of its poor warning properties. Early stages of CO intoxication are nausea and headache. Carbon monoxide may be fatal at 1000 ppm in air, and is considered dangerous at 200 ppm, because it forms carboxyhemoglobin in the blood which prevents the distribution of oxygen in the body.


Carbon monoxide

Hydrogen sulfide

Is one of the most common asphyxiates. Produced by the incomplete combustion of carbon fuels, carbon monoxide kills by chemically combining with the hemoglobin in red blood cells. This greatly reduces the ability of the blood to carry oxygen to body tissues and brain cells.


Is even more toxic than carbon monoxide. It is produced through the decay of organisms and natural materials. This colorless gas has a characteristic rotten egg odor at first;  however, within a short time the gas paralyzes the olfactory nerve, which controls the sense of smell. A worker may be lulled into a false sense of security because he/she no longer smells the substance, yet it is causing serious bodily harm (higher concentrations).





35 ppm

Permissible Exposure Limit during an eight-hour shift.

10 ppm

Permissible Exposure Limit during an eight-hour period.

500 ppm

Slight headache.

50-100 ppm

Mild eye and respiratory irritation.

1000 ppm

Confusion, nausea, discomfort.

200-300 ppm

Marked increase in eye and lung irritation.

2000 ppm

Tendency to stagger.

500-700 ppm

Unconsciousness or death after a 30-minute exposure.

2500 ppm

Unconsciousness after a 30-minute exposure.

1000 or more ppm

Death within minutes.

4000 ppm

Fatal in less than one hour.





Common corrosive irritants which can be present in confined spaces include chlorine, ozone, hydrochloric acid, hydrofluoric acid, sulfuric acid, nitrogen dioxide, ammonia, and sulfur dioxide. The past use (history) of the space may require the need for surface/atmospheric testing.


Physical Hazards

Employees working in confined spaces may face the following physical hazards:

  • The possibility of drowning or being trapped by flooding water while working in a storm sewer or wet- well.
  • Pipes, valves, and lines carrying harmful substances such as steam, natural gas, and electricity that can rupture while being worked on or activated if not locked out.
  • Loud noises reverberating from the use of hammers or hydraulic equipment.
  • Exposure to temperature extremes during work activities.
  • Slips and falls on wet or damaged walking or climbing surfaces.
  • Exposure to corrosive substances that could irritate unprotected skin.
  • Exposure to rodents, vermin, and other pests living in the area.
  • Poor or inadequate lighting.
  • Accidental activation of hazardous equipment while it is being repaired.


Moving equipment or parts and energized or pressured systems can be dangerous as well. Examples include shafts, belts, conveyors, mixers, rotors, and compressing devices. Entrapment hazards in a confined space include inwardly converging walls or floors that slope downward and taper to a smaller cross-section, such as air plenums. An engulfment hazard is any liquid or loose, finely divided solid material such as sand or grain that could bury, surround, suffocate, or drown an entrant.

Entry & Exit

Entry and exit time is of major significance as a physical limitation and is directly related to the potential hazard of the confined space. The extent of precautions taken and the standby equipment needed to maintain a safe work area will be determined by the means of access and rescue. The following should be considered: type of confined space to be entered, access to the entrance, number and size of openings, barriers within the space, the occupancy load, and the time requirement for exiting in event of fire or vapor incursion, and the time required to rescue injured workers.

Thermal Effects: Heat

Four factors influence the heat exchange in confined spaces: (1) air temperature, (2) air velocity, (3) moisture contained in the air, and (4) radiant heat. Ventilation of the confined space is critical since moisture content and radiant heat are difficult to control. Workers will continue to function until the body temperature reaches approximately 102oF. Above this level, workers are less efficient, and are prone to heat exhaustion, heat cramps, or heat stroke.


In a cold environment, physiologic mechanisms tend to limit heat loss and increase heat production. The most severe strain in cold conditions is chilling of the extremities so that activity is restricted. Special precautions must be taken in cold environments. Using protective insulated clothing for both hot and cold environments will add additional bulk to the worker and must be considered in allowing for movement in the confined space and exit time. Therefore, air temperature of the environment becomes an important consideration when evaluating working conditions in confined spaces.


Rescue procedures may require withdrawal of an injured or unconscious person. Rescue from confined spaces must be carefully planned with attention given to the relationship between the internal structure, the exit opening, and the worker. If the worker is above the opening, the system must include a rescue arrangement operated from outside the confined space, if possible, by which the employee can be lowered and removed without injury.

Personal Protective Equipment (PPE) and Entry Equipment:

Personal protective equipment (gloves, boots, safety glasses, coats, etc.) may be necessary and is usually required for safe entry into confined spaces. Entry Equipment may include equipment for atmospheric testing, ventilation, communication, lighting, and rescue. Personal protective equipment appropriate for the hazards of the space must also be provided to workers.


Departments must inform outside contractors of the potential hazards that may be encountered during their work at the University. This includes giving the contractor access to any information available on the confined spaces involved in their project.

Similarly, the contractor must inform the Department of any changes made to a confined space in the course of their work. Any change, no matter how minor, would require a re-evaluation of the space before entry would again be allowed.


Some physical hazards cannot be eliminated because of the nature of the confined space or the work to be performed. The use of scaffolding in confined spaces has contributed to many accidents caused by workers or materials falling, improper use of guard rails, and lack of maintenance to insure worker safety. The choice of scaffolding depends upon the type of work, the calculated weight to be supported, the surface on which the scaffolding is placed, and the substance previously stored in the confined space.

Structural Hazards:

Typical internal structure hazards within a confined space include baffles in horizontal tanks, trays in vertical towers, bends in tunnels, overhead structural members, or scaffolding (above) installed for maintenance. Workers must review these hazards plus implement and enforce safety precautions to manage these hazards.

Communication Hazards:

Communication between the worker inside and the standby person outside is of utmost importance. If the worker should suddenly feel distressed and not be able to summon help, an injury could become a fatality. Frequently, the body positions that are assumed in a confined space make it difficult for the standby person to detect an unconscious worker. When visual monitoring of the worker is not possible because of the design of the confined space or location of the entry hatch, a voice or alarm-activated explosion proof type of communication system will be necessary. Suitable illumination of an approved type is also required.


Mechanical Hazards:

Lockout/Tagout/Static Charges

The most hazardous kind of confined space is the type that combines limited access and mechanical devices. If activation of electrical or mechanical equipment would cause injury, each piece of equipment should be manually isolated (lockout/tagout) to prevent inadvertent activation before workers enter or while they work in a confined space. The interplay of hazards associated with a confined space, such as the potential of flammable vapors or gases being present, and the build-up of static charge due to mechanical cleaning, such as abrasive blasting, all influence the precautions which must be taken.

Vapor Leaks

To prevent vapor leaks, flashbacks, and other hazards, workers should completely isolate the space. To completely isolate a confined space, the closing of valves is not sufficient. All pipes must be physically disconnected or isolation blanks bolted in place. Other special precautions must be taken in cases where flammable liquids or vapors may re-contaminate the confined space. The pipes blanked or disconnected should be inspected and tested for leakage to check the effectiveness of the procedure. Other areas of concern are steam valves, pressure lines, and chemical transfer pipes.


Noise problems are usually intensified in confined spaces because the interior tends to cause sound to reverberate and thus expose the worker to higher sound levels than those found in an open environment. This intensified noise increases the risk of hearing damage to workers which in a confined space may not be intense enough to cause hearing damage may still disrupt verbal communication with the emergency standby person on the exterior of the confined space. If the workers inside are not able to hear commands or danger signals due to excessive noise, the probability of severe accidents can increase.


Whole body vibration may affect multiple body parts and organs depending upon the vibration characteristics. Segmental vibration, unlike whole body vibration, appears to be more localized in creating injury to the fingers and hands of workers using tools, such as pneumatic hammers, rotary grinders or other hand tools which cause vibration.

Cutting & Welding in Confined Spaces:

Hazards result from the fumes, gases, sparks, hot metal and radiant energy produced during hot work and should not be conducted in the presence of explosive mixtures of flammable gases, vapors, liquids, or dusts or where explosive mixtures could develop inside improperly prepared tanks or equipment. Atmospheric testing and monitoring for combustible gases and vapors should be done before work begins and at regular, predetermined intervals thereafter. Ventilation of the work site, either through local or general exhaust ventilation, should be adequate for the work performed.

Surface Residues

Surface residues in confined spaces can increase the already hazardous conditions of electrical shock, reaction of incompatible materials, liberation of toxic substances, and bodily injury due to slips and falls. Without protective clothing, additional hazards to health may arise due to surface residues.


General Requirements & Regulatory Overview

Campus and field-station workspaces require confined-space evaluations prior to entry. While it may ultimately be determined that a space is not defined as a confined space, special care may still be necessary while preparing, entering, and conducting work in the space.

Procedures for evaluating, entering, and working in confined spaces vary depending on space configuration and the type of work performed. With the goals of avoiding injuries and fatalities, and assuring Cal/OSHA compliance, each department or research group intending to enter such a space must establish a

Confined Space Plan that includes:

  • Evaluation of potential physical and atmospheric hazards to determine the type of confined space,
  • Safe means of entry into and performing activities in the confined space, and
  • Safe emergency evacuation in the event of injuries or unforeseen atmospheric hazards.

In general, the evaluation and planning consists of the following:

  • A scope of work defined by the supervisor.
  • A thorough analysis of the hazards associated with the space.
  • A decision on the type of confined space (Construction versus Non-construction Space).
  • Establishment and implementation of appropriate controls for recognized or potential hazards.
  • Continuous monitoring of potential, existing, and newly identified hazards and modification of controls accordingly.
  • Planning for immediate evacuation should new or previously unidentified hazards be found.
  • Methods for communication between those within the confined space and to those outside.
  • Staging of emergency response equipment to be immediately available for use should a rescue be needed.


Department Requirements

The Department with operations that involve working in confined space shall designate a "Confined Space Safety Program Coordinator(s)" responsible for the following actions:

  • Ensures that equipment purchased and used in the department are code-compliant and appropriate for the needed safe-work tasks.
  • Consults with the Department of Safety and Risk Management (SRM) as needed to assess proper use and procurement specifications.
  • Coordinates with SRM to provide documented safety training, or provides training themselves (by JSA or other presentation), to all department personnel who enter confined space.
  • Periodically audits departmental compliance with the Confined Space Safety Program and advises SRM of process management updates.
  • Only allows persons who have successfully completed documented training to use conduct work in confined space.
  • Informs SRM when new equipment is purchased so it can be added to the SRM confined space safety equipment inventory.
  • Ensures that all confined space safety equipment owned by the department has documented inspections completed by SRM every month.
  • At least annually reminds the users of their requirements under this program.


Identifying Confined Spaces at Cal Maritime

Confined space--as defined by Cal-OSHA, a space that has all three of the following characteristics: is large enough and configured such that an employee can enter and perform work, has limited openings for entry and exit, and is not designed for continuous employee occupancy. Two main hazards associated with confined spaces are atmospheric hazards and physical hazards. Atmospheric hazards typically involve problems with the air in a space (i.e., lack of oxygen, the presence of other gasses in the space, insufficient ventilation, etc.). Physical hazards are those caused either by equipment (rotors, sparks, moving machinery, energized systems, etc.) or by other dangerous conditions (slippery surfaces, heat, noise, lighting, vermin, insects, etc.). Examples of confined spaces include silos, tanks, vats, boilers, ducts, sewers, manholes, pipelines, vaults, bins, tubs, excavations, trenches, pits, wet wells, fireboxes, boxcars, and other confining structures.

Excavation, trenching, and shoring

  • Excavation--any man-made cut, cavity, trench, or depression in an earth surface, formed by earth removal.
  • Trench--a narrow excavation (in relation to its length) made below the surface of the ground. In general, the depth is greater than the width, but the width of a trench is not greater than 15 feet.
  • Shoring--a structure such as a metal hydraulic, mechanical, or timber shoring system that supports the sides of an excavation and is designed to prevent cave-ins.
  • Benching--A method of protecting employees from cave-ins by excavating the sides of an excavation to form one or a series of horizontal levels or steps, usually with vertical or near-vertical surfaces between levels.
  • Competent person--one who is capable of identifying existing and predictable hazards in the surroundings or working conditions that are unsanitary, hazardous, or dangerous to employees, and who has authorization to take prompt corrective measures to eliminate them. The competent person must be able to demonstrate the following: the ability to recognize all possible hazards associated with excavation work and to test for hazardous atmospheres; knowledge of the current safety orders pertaining to excavation, trenching, and shoring; the ability to analyze and classify soils; knowledge of the design and use of protective systems; and the authority and ability to take prompt corrective action when conditions change.

Forklift truck--a mobile power-driven truck (gasoline, propane, electric, etc.) used for hauling, pushing, lifting, or tiering materials where normal work is normally confined within the boundaries of a place of employment.

Oxyacetylene welding--commonly referred to as gas welding, a process that relies on combustion of oxygen and acetylene within a hand-held torch or blowpipe. The chemical action of the oxyacetylene flame can be adjusted by changing the ratio of the volume of oxygen to acetylene.

Soldering and brazing--joining processes where parts are joined without melting the base metals. 1. Soldering filler metals melt below 840°F and is commonly used for electrical connection or mechanical joints. 2. Brazing filler metals melt above 840°F and is only used for mechanical joints due to the high temperatures involved.

Normal operational tasks in manholes, meter vaults, and valve boxes require the use of an Entry Log. Operations within the wet side of sewer lift stations, boilers, and fireboxes, or spaces requiring Hot Work, require a Permit.

All permit-required confined spaces will be posted. Posting of non-permit confined spaces is optional. Examples of permit-required confined space signs are as follows:

If you are asked to enter a space you believe may be hazardous to your health, please discuss with your supervisor and/or SRM to determine whether it should be classified as a confined space.


It is mandatory that an atmospheric monitoring instrument be used before and continuously during any confined space entry. There are several types of atmospheric monitoring instruments used by various campus divisions. These monitors continually sample the atmosphere to which the worker is being exposed. Liquid crystal digital screens and audible alarms on these monitors are preset to activate when high contaminant levels are sensed. Each instrument monitors air samples in four categories simultaneously:

  • Percent of available oxygen;
  • Percent of flammable gases;
  • Presence of hydrogen sulfide; and
  • Presence of carbon monoxide.

Other instruments used at Cal Maritime may not be capable of continuous monitoring; rather, they are designed to monitor a single sample of drawn air for certain contaminants. These older models are larger, not worn on the employee's belt and must be activated each time a new sample is needed. These monitors may or may not be able to analyze the sample for more than one type of contaminant at once. At a minimum, every employee performing atmospheric monitoring should be able to retrieve sampling information about the oxygen level as well as the presence of both toxic and flammable gases. This may be possible only by using several different instruments.

Regardless of the type of instrument being used, each requires periodic maintenance and calibration. Specific manufacturer's instructions must be followed to ensure each instrument provides reliable service. Replacement parts, including extended probes and carrying cases, should be purchased directly from the manufacturer or manufacturer's representative.

Each of these monitors is a highly sophisticated scientific instrument that must be carefully handled and maintained in order to provide critical, lifesaving information to the user. These instruments are capable of detecting hazardous atmospheric conditions far beyond that of human senses.

Entry Logs and Permits

  • Most confined space operations at Cal Maritime facilities are considered permit required confined spaces and require the Permit-Required ConfinedSpaceEntryPermit. The purpose of the Entry Log     or Permit is to make sure all necessary precautions are taken before entry is made.
  • Copies of the Entry Log and Permit are available through SRM and the safety coordinator's office at O&M.
  • All Entry Logs and Permits are to be kept at the job site until the operation is completed.
  • All measurement data from the sampling activities are to be recorded on the Entry Log or Permit. All Entry Logs and Permits are to be signed and kept in departmental records for three years. Such records must be available for periodic inspection by applicable employees, their representatives, SRM staff, and Cal-OSHA inspectors.

The following four steps must be taken before entering any known or suspected confined space on campus:

STEP 1 - Determine Whether an Entry Log or Permit is Required:

  • Before entering any known or suspected confined space, employees may refer to the "IsItSafeTo
  • The flow chart is designed to assist in determining whether an Entry Log or Permit is required to enter a space.
  • If hazards are present, a Permit must be completed. The Department of Safety & Risk Management must be notified and a Cal Maritime departmental supervisor's written approval must be obtained prior to entering the space.

STEP 2 Organize the Equipment

Before entering a confined space, obtain the following items:

  • An Entry Log or Permit;
  • Air monitoring equipment (check the battery and calibration status.);
  • Ventilation equipment and its power supply, if applicable;
  • Personal Protective Equipment (PPE);
  • Standby personnel and communication equipment;
  • Appropriate barricades; and
  • Fall protection and retrieval equipment, if applicable.

STEP 3 - Securing the Environment

  • Lock Out/Tag Out (LOTO) - All LOTO procedures will be followed before entering a confined space.
  • Wet-Wells - Lock valves or blind lock pipes if possible. A harness and a winch retrieval system are mandatory.
  • Steam Boilers - Before employees enter one of a battery of boilers or a boiler connected to another source of steam, the valve connection to the steam header or source must be closed and blinded, or there must be two closed valves with an open bleeder between them.
  • Blow-down valves and other valves on lines through which hot water or steam might accidentally flow back to the boiler must be closed, locked out, and tagged out. The employee entering the boiler must keep the key. This is not necessary if the lines are blinded.
  • Fire Boxes, Flues and Combustion Chambers - Before entering a confined space, make sure the pilot light, the fuel, and steam lines have been blinded and disconnected or have two closed block valves with an open bleeder between them.
  • Water Tanks - Valves that could admit water must be closed, locked out, and tagged out. The employee entering the space must keep the key.
  • Spaces with Potentially Harmful Electrical Equipment - This equipment must be disconnected with the disconnect switch, then locked out and tagged out. The employee entering the space must keep the key.
  • Spaces with Fire Suppression Systems That Use Oxygen-Displacing Gas - The system must be deactivated before entry.
  • Spaces Pedestrians Could Fall Into - Set up appropriate barricades in all pedestrian-accessible areas.
  • Spaces Where Employees Could Fall - Use a harness and winch setup to prevent falls.

STEP 4 - Initial Monitoring

  • Use an appropriate meter that has been recently field calibrated with all sensors operating. There are meters available to O&M personnel at the Mechanical Safety Coordinator's office.
  • Pre-test air monitors - Activate the instrument, and allow it to warm up, checking the instrument's operation condition and battery charge level.
  • Air monitor probe use - While the air-monitoring instrument is running, remove the protective boot and attach the probe. Insert the probe into the weep hole, or if there is no weep hole, open the manhole or cover enough to insert the probe. If instrument readings are within acceptable limits, perform level testing starting at the bottom of the confined space working upward every 4 feet until all of the vertical space has been tested. Record your finding on the Entry Log or Permit. Where interconnecting spaces are blinded off, each space must be monitored separately.
  • If the instrument alarms or detects any unacceptable levels of toxic gases, STOP. Do not enter the space. Call your supervisor, the Safety Coordinator, or SRM immediately.

Example of Level Air Monitoring Using the Probe Attachment

  • Insert the probe into the weep hole, or if there is no weep hole, open the manhole enough to insert the probe (1).
  • If instrument readings are within acceptable limits, the manhole cover may be removed.
  • Before entering the confined space, perform level testing starting at the bottom of the confined space working upward every 4 feet until all of the vertical space has been tested (2-6).
  • Use of Personal Air Monitors - While the air monitor is still running, remove the probe and attach the protective boot and carry case. The instrument is to remain running and in the confined space with the entrant at all times

Entry Procedures

Once the initial tests are completed and the atmosphere has been determined to be within acceptable limits, visually inspect the area for any additional hazards. If no other hazards are observable, work may proceed using the following procedures.

Log Entry (Non-Permit Required Confined Space)

  • A minimum of two employees is required for a non-permit required confined space entry. One employee will remain outside of the space to be available in case of an emergency. This individual must be in direct communication with the entrant as well as be able to contact emergency response personnel.
  • Portable blowers may be used to purge stagnant air or to provide comfort ventilation during confined space work. The blower intake must be located outside of the confined space and away from any operating internal combustion engine to ensure that fresh air is being supplied. The blower should be activated before an employee enters.
  • Entrants must have an air-monitoring instrument on and with them at all times while in the confined space.
  • If at any time atmospheric conditions change and the monitor indicates (alarms) the presence of toxic or flammable gases or a change in oxygen level, employees are to evacuate the space at once. Call your supervisor, the Safety Coordinator, or SRM immediately.

Permit Entry (Permit-Required Confined Space)

  • A minimum of two, and preferably three employees is required for a permit-required confined space entry. The entry supervisor may or may not be present at the immediate entry site. The attendant(s) will remain outside the space to be available in case of an emergency. One individual must be first aid and CPR trained, must maintain direct communication with the entrant at all times, and must be able to contact emergency response personnel.
  • At no time will the attendant or entry supervisor enter the permit-required confined space.
  • Portable blowers must be used during permit-required confined space work. The blower intake must be located outside of the confined space and away from any operating internal combustion engine to ensure that fresh air is being supplied. The blower must be activated before the employee enters the space.
  • All authorized entrants and rescuers must wear a full body harness and retrieval line, unless the retrieval equipment would increase the overall risk of the entry or would not contribute to the rescue operation.
  • Only approved lowering devices designed by the manufacturer for moving humans shall be used. The equipment must enable a rescuer to remove the injured employee from the space quickly without injuring the rescuer or further harming the victim.
  • Entrants must have air-monitoring instruments on and with them at all times while in the confined space.
  • If at any time atmospheric conditions change and the monitor indicates (alarms) the presence of toxic or flammable gases or a change in oxygen level, employees are to evacuate the space at once. Call your supervisor, the Safety Coordinator, or SRM immediately.


 Other Operations with Confined Spaces

 Hot Work

"Hot Work" includes any operation capable of providing an ignition source. Examples include welding, torch work, electric tools with open brushes, sanders, grinders or any device that produces sparks. Special precautionary measures can be taken to reduce the risk of fire or explosion including improving ventilation, inspecting for frayed electrical wires, implementing a fire-suppression system or using low-voltage, non-sparking tools.

Prior to any Hot Work on campus, a Hot Work permit must be obtained from the Department.

Dangers Created by Work Procedures

Work performed within a confined space (such as welding, decreasing, painting, sanding, or using pesticides) may create a toxic atmosphere. Finely powered dust from combustible materials such as wood, metal, or grain can be fuel for a powerful explosion. Dust clouds can develop as a result of handling dusty materials or when solid materials are reduced to smaller particles from processes such as grinding, drilling or crushing. Airborne combustible dust at an explosive concentration will reduce vision to a distance of 5 feet or less. Caution must be used when performing tasks that could change the atmosphere in a confined space.

Lock Out/Tag Out (LOTO)

LOTO is the procedure for shutting off, securing or isolating equipment to prevent an undesirable release of hazardous energy during any servicing, maintenance or modification activity. LOTO procedures are mandatory and must be strictly followed by all employees working on equipment that may release hazardous forms of energy including, but not limited to, electrical, rotational, mechanical, chemical, hydraulic, or pneumatic energy.

Most LOTO injuries can be traced to the following causes:

  • Failing to stop equipment;
  • Failing to disconnect from the power source;
  • Failing to dissipate residual energy;
  • Accidentally restarting equipment; or
  • Failing to clear work areas before reactivation.

Rescue Plan

Emergency and Rescue Procedures Overview

The Vallejo Fire Department will provide emergency extraction/rescue services.  Cal Maritime personnel, will not perform emergency entry rescues under any circumstances. Cal Maritime personnel are not currently trained as emergency rescuers, nor do they have the required equipment to provide emergency rescues in confined spaces.

Employees working in confined spaces must only perform self-rescue and/or non-entry rescue procedures.

  • Self-rescue: Self-rescue is the preferred plan. The self-rescue plan provides entrants with the best chance of escaping a space when hazards are detected. Whenever authorized entrants recognize their own symptoms of exposure to dangerous atmosphere or detect a dangerous condition, entrants are still able to escape from the space unaided and as quickly as possible.
  • Non-entry rescue: Non-entry rescue is the next best approach when self-rescue is not possible. Non-entry rescue can be started right away and prevents additional personnel from being exposed to unidentified and/or uncontrolled confined space hazards. Usually, equipment and other rescue aids, such as a full body harness with a retrieval tripod, are used to remove endangered entrants.
  • Entry-rescue: In this procedure, emergency response personnel from the Fire Department, enter the space to retrieve the entrant or provide the victim with emergency assistance such as CPR, first aid, or air via SCBA or a supplied air respirator.

Emergency response personnel will need to know the following information:

  • The number of victims and the location of the emergency
  • How long the victim(s) have been exposed to the hazard or how long the victim(s) have been injured/down
  • The suspected cause of the accident
  • In addition, emergency response personnel will need to know all information on the Entry Log or Permit including:
  • Atmospheric test results
  • Isolation or LOTO procedures
  • Safety Data Sheets (SDS), if applicable
  • Hot Work, if applicable
  • Any other relevant information

Retrieval System

The retrieval system is primarily used in confined space applications where workers must enter tanks, manholes, etc., and may require retrieval from above should an emergency occur. Retrieval Systems may also be used in rescue after a fall has occurred and the victim is hanging by the Fall Arrest System in suspension. A retrieval system typically consists of:



Acceptable entry conditions.

Prerequisite conditions for safe entry into and work in a confined space.



An individual stationed outside of a Construction-Telecommunications confined space to monitor authorized entrants and summon help as needed.


Atmospheric monitor.

A trained individual qualified in the use of atmospheric testing equipment, who determines if atmospheric hazards are present within a confined space.


Atmospheric testing.

The process of identifying and evaluating atmospheric hazards in a Construction- Telecommunication confined space using real-time monitoring instrumentation. Atmospheric monitoring must include tests for combustibility, toxicity, and proper oxygen levels. Atmospheric testing enables entry supervisors to devise and implement adequate control measures for the protection of entrants, and to determine if acceptable entry conditions are present immediately before and during entry.


Blanking or blinding.

The absolute closure of a pipe, line, or duct by application of a solid plate (e.g., a spectacle blind or skillet blind) that completely covers the bore and can withstanding the maximum pressure of the pipe, line, or duct without leaking

Confined space owner.

The person (building coordinator, department safety coordinator [DSC], principal investigator [PI], and/or experimenter) who has administrative control over the confined space, and who has knowledge of the chemical and/or physical hazards associated with it.



A person not directly employed by the University who is contracted to perform work on University property, which may include confined space entry.



The closure of a pipe, line, or duct by first closing, locking, and tagging two in-line valves, and then opening and locking or tagging a drain or vent valve in the line between the two closed valves.



Any event or occurrence internal or external to a confined space (including failure of hazard controls or monitoring equipment) that could endanger entrants.




The surrounding and effective capture of a person by a liquid or finely divided (flowable) solid substance that can (1) be aspirated and cause death by filling or plugging the respiratory system, or (2) exert enough force on the body to cause death by strangulation, constriction, or crushing.



An individual authorized to enter a Construction, Electrical or Telecommunications confined space.


The action by which a person passes through an opening into a Construction, Electrical or Telecommunications confined space. "Entry" includes work activities within the space, and is considered to have occurred as soon as any part of the entrant's body breaks the plane of an opening into the space

Entry supervisor.


The individual (supervisor, foreman, lead, or other designated person) responsible for (1) overseeing operations at the confined space, (2) ensuring that all entry conditions are met, (3) authorizing entry, and (4) transferring and/or terminating the entry.

Exhaust ventilation.


The method of removing contaminants from a confined space by using localized suction at the source of the contaminant.

Forced-air ventilation.


The method of diluting or dissipating actual or potentially hazardous atmospheres to safe levels in a confined space by using mechanical blowers to push air into the space. Forced-air ventilation may be required on confined spaces with hazardous atmospheres, and may be used in combination with exhaust ventilation.

Hazardous atmosphere.

An atmosphere that exposes employees to risk of death, incapacitation, acute illness, or impairment of the ability to rescue themselves. A hazardous atmosphere can occur from one or more of the following causes:

  • Flammable gas, vapor, or mist greater than 10 percent of the lower flammable limit (LFL);
  • Airborne combustible dust at a concentration that meets or exceeds its LFL;
  • Oxygen concentration of less than 19.5 percent or greater than 23.5 percent;
  • Carbon monoxide greater than 35 ppm;
  • Hydrogen sulfide greater than 10 ppm; and/or
  • Any airborne contaminant that may expose a worker above the contaminant's permissible exposure limit (PEL) or be "immediately dangerous to life or health" (see below).



Operations employing potential source(s) of ignition (e.g., welding, cutting, burning, soldering, and heating).

Immediately dangerous to life or health.

Any condition that poses an immediate or delayed threat to life, would cause irreversible adverse health effects, or would interfere with an individual's ability to escape unaided from a Construction, Electrical or Telecommunications confined space

Inerting (rendering inert).

The displacement of flammable gases from a system (piping, pressure, etc.) by injecting a non-combustible inert gas such as nitrogen.


The process by which a Construction, Electrical or Telecommunications confined space is removed from service and completely protected from release of energy and material into the space by any of the following means:

Blanking, blinding, misaligning, or removing sections of lines, pipes, or duct;

Using a double-block-and-bleed system;

Locking or tagging out all sources of energy; and/or

Blocking or disconnecting all mechanical linkages.

Lockout and tagout (LOTO).

The process by which hazards are locked out or tagged out, providing personnel with complete protection against chemical, electrical, and mechanical energies. For more information, obtain a copy of Lockout and Tagout: Procedures to Control Hazardous Energies from SRM.

Non-entry rescue.

Use of a retrieval system to remove ill or injured entrants from a confined space without entering the space.

Oxygen-deficient atmosphere.

An atmosphere containing less than 19.5 percent oxygen by volume.


Oxygen-enriched atmosphere.

An atmosphere containing more than 23.5 percent oxygen by volume.


Prohibited condition.

Any condition not allowed in a Construction, Electrical or Telecommunications confined space during the period when entry is authorized.


Retrieval system.

The equipment (including a retrieval line; chest or full-body harness; wristlets, if appropriate; and a lifting device and anchor) used for non-entry rescue of persons from a Construction, Electrical or Telecommunications confined space.


Standby rescue service or team.

Personnel trained and designated to enter confined spaces for the purpose of rescuing ill or injured entrants.



Other Resources

Cal Maritime and its subcontractors shall comply with the following requirements.

In case of conflict or overlap of the below references, the most stringent provision shall apply.

  • Occupational Safety and Health Act (OSHA), 1904, 1910, 1915,1917,1918,1926
  • California Code of Regulations (CCR), Title 8, GISO, CSO, ESO
  • §5156-5158. Confined Space.
  • §4794-4848. Gas Systems for Welding and Cutting
  • Sections 3649-3669, Industrial Trucks, Tractors, Haulage Vehicles, and Earthmoving
  • Section 3314, Cleaning, Repairing, Servicing, and Adjusting Prime Movers, Machinery, and Equipment.
  • Sections 1539-1547, Excavations
  • §1669. General Requirements for Fall Protection Use.

Fed/OSHA Fall Protection Regulations




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Cal OSHA Confined Space Guide


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