Defining OSHA Confined Spaces, Meeting Requirements

Confined Space OSHA Definition

What is OSHA's definition of a "Confined Space"?

In the gas detection world we often refer to the Occupational Safety and Health Administration (OSHA)  when referencing required workplace safety standards, assessments, and guidelines as they pertain to particular industries.

A common term that is often recognized across a variety of industries, but often misunderstood or misconstrued is "confined space".

According to OSHA, a confined space is defined as the following with these three specific criteria:

1. A space large enough to enter in and work

2. A space which holds limited opening for entry and exit

3. A space not designed for continual worker occupancy

A confined space must meet ALL or ANY of the above criteria to be designated a "confined space". 

When discussing confined spaces and OSHA, there are two distinctly different types of confined spaces called "non-permit confined spaces" and "permit-confined spaces". 

Non-Permit Confined Spaces are defined as: a space that does not have a hazardous atmosphere, cannot engulf an individual or asphyxiate upon entry, does not hold internal configuration hazards, and does not contain any recognizable hazard.

Permit Confined Spaces are defined as:   a confined space that has one or more of the following criteria:

1. Contains, or has the potential to contain a hazardous atmosphere

2. Contains material that can have the potential to engulf an individual/entrant

3. Has walls that converge inward, or floors that slope downward and taper into a small restricted area that could asphyxiate or trap an entrant

4. Contains any other recognized safety or health hazards

5. Is large enough and configured that an employee can bodily enter and perform assigned work

6. Has limited or restricted means for entry or exit (ex., tanks, silos, keg coolers, storage bins, vaults, and pits)

7. Is not designed for continuous employee occupancy

The Code of Federal Regulations created 29 CFR 1910.146 for OSHA.  29 CFR was written to place an affirmative duty on employers to train their employees and staff who work and enter confined space locations. This code also places a particular emphasis on those individuals to be aware of the potential hazards, recognize the precautions to take, and be knowledgeable about protective equipment needed to safely perform tasks and duties

Ironically, although OSHA created and actively promotes these standards many individuals throughout the beverage, brewery, agriculture, and safety industries are unaware of the standards and lack the knowledge needed to work in and around these hazardous spaces.

 Atmospheric Monitoring in Confined Spaces

Because such confined space exists, there are certain atmospheric monitors and gas detection solutions that have been designed specifically for detecting gas concentrations in hazardous environments. Although individuals working in and around confined spaces may tend to believe they can detect if a hazardous gas is present, there is no other tool that can sense gas concentrations more effectively, quickly, and accurately as a  professionally designed and manufactured gas monitor, detector, or analyzer.

Without proper fixed or portable monitoring in place, individuals can quickly experience overexposure to hazardous gases.  Symptoms can include fatigue, headaches, nausea, asphyxiation, and even death from overexposure.

OSHA additionally specifies that "In order to enter any confined space without the use of special types of personal protective equipment or monitoring, such as a self-contained breathing apparatus - atmospheric conditions must have these characteristics:"

  • Oxygen: 19.5 percent to 23.5 percent 
  • Flammability: below 10 percent of the lower flammable limit (LFL) for gases, vapors, mists or combustible dust
  • Toxic gases: below the permissible exposure limit (PEL)/threshold limit value (TLV) or time-weighted average (TWA) of a substance

Should a hazardous space contain higher than allowable gas concentrations, utilizing a proper gas detection monitor is a must and will instantly alert the users that higher concentrations are present by audible and visual indicators.

Confined Space Equipment and Monitoring

A gas detection solution that is sought after across many industries worldwide, is a portable carbon dioxide monitor, like the SAN-10 Personal 5% CO2 Safety Monitor and Data Logger. 

The SAN-10 was designed for employees who work in enclosed areas where carbon dioxide buildup may cause personal harm. In addition, the device also features audible/visual alarm indication, exclusive data logging capabilities (GasLab Software), and a man down alarm that is triggered when an employee fall occurs.

By utilizing a personal, portable gas detector these devices can further allow the individual peace of mind when entering into a confined space with an instant on-the-go solution and indicator should gas concentrations exceed safety levels.

For those looking to monitor oxygen depletion safety, see the SAN-20 Personal O2 Safety Monitor

A common gas detection monitoring system that is used throughout beverage, brewing, agriculture, restaurant, and safety industries is the CM-7000 Multi-Sensor CO2 Safety System.

This device was designed to detect carbon dioxide (CO2) concentrations in confined spaces such as fermentation cellars, keg coolers, indoor greenhouses, and mechanical rooms. 

With the CM-7000, hazardous CO2 gas concentrations can be detected instantaneously by the device's NDIR CO2 sensor measuring 30 times per minute.  The device is equipped with audible and visual alarm indicators as well as displaying the PPM level on an 8 inch LCD touchscreen display. The device also allows the user to trigger an exhaust fan or send an alert to the fire control panel. For those looking to detect multiple gas concentrations, our CO2Meter team recommends utilizing a device such as the CM-1000 - Multi-Gas Sampling Data Logger

Additional Maintenance Equipment Includes:

  1. Gas-detection equipment
  2. Ventilating equipment
  3. The proper signage
  4. Communication equipment (if necessary)
  5. PPE to be used when engineering controls such as ventilation equipment is not practical
  6. Lighting equipment
  7. Barricades to prevent unauthorized entry (Ladders to provide safe access to and egress from the permit space)
  8. Rescue and emergency equipment (unless this service is already provided)

Confined Space OSHA Requirements

For those individuals, team members, and staff that are required to enter confined space environments, OSHA has established a list of criteria that is to be met and must be adhered to for meeting standards and procedures.

  • A written program must be developed addressing potential hazards and precautions
  • Inform those employees who have not been trained in the standard to keep away during the entry activities
  • Each employee who is involved or has the potential to be involved in confined-space entries must be trained before entering any space
  • Use appropriate signs and barricades to prevent entry from others
  • Identify and evaluate hazards in the permit space, before entry
  • Specification of acceptable entry procedures. This includes having an oxygen content between 19.5 percent and 23.5 percent, LFL of substances below 10 percent and below established PELs, TWAs, and TLVs. – Isolation of the permit space
  • Lockout/Tagout procedures will be followed on all applicable equipment.
  • Indication of specific locking and tagging equipment to prohibit use while the entry is taking place. (Ex: Control or elimination of atmospheric hazards through purging, inerting, flushing or ventilating)
  • Maintenance of appropriate gas detection/ventilation equipment

    For an example of a confined space written program template, view this free, handy, sheet - curated by the Brewer's Association Safety Committee - here.

    Common Examples of Typical Confined Spaces

    1. Oxygen-deficient atmospheres
    2. Vaults
    3. Condenser Pits
    4. Fermenters, Mash Tuns, Silos
    5. Keg Coolers (Cold Box)
    6. Manholes
    7. Pipe assemblies
    8. Ventilation Ducts
    9. Chemical/Water Tanks
    10. Sumps
    11. Containment Cavities
    12. Heat Sinks
    13. Electrical Transformers

    Why are OSHA Confined Space Standards and Training Important?

    There are several safety precautions that individuals need to be aware of in their daily work environments, however, confined spaces have continued to be recognized as critical due to the number of deaths and fatalities around confined space and hazardous gas exposure.

    According to OSHA, from 2005-2011 there were a total of 481 confined space entry fatalities, and 160 deaths as a result of hazardous atmospheres.

    Where to gain additional guidance?

    After ensuring you and your employees are educated on proper confined space guidelines, precautions, and standards you should be on the right track towards confined space safety and overall workplace/staff gas exposure prevention.  OSHA compliant consultants and training sessions are available online as well.

    For more information on confined space and OSHA procedures or additional training, reach out to our CO2Meter support staff at or (877) 678 - 4259.

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