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Voice of Experience: Understanding Enclosed and Confined Spaces

What is the difference between an enclosed space and a confined space? Many companies do not acknowledge 29 CFR 1910.269(e), “Enclosed spaces.” Instead, they handle all spaces as confined under 1910.146, “Permit-required confined spaces,” and a few companies even handle them all as permit-required spaces. There may be some confusion and there certainly is much industry discussion about the spaces in which employees are asked to work. In this article, I will highlight several of the major differences between the spaces, as well as provide an overview of each of the OSHA standards.

Where OSHA is concerned, the most noticeable differences between enclosed and confined spaces relate to rescue and attendant duties. Much of training and entry, on the other hand, is very similar. Attendants must be trained in first aid and CPR, recognize and understand all possible hazards in the spaces, and monitor employees for unusual behaviors that may be caused by atmospheric hazards that have developed in spaces where the employees are present. Pre-entry checklists, including atmospheric checks, should be completed for all spaces to determine if acceptable entry conditions exist.

A Closer Look
Now let’s take a closer look at the real meaning of the two types of spaces. A confined or enclosed space can come in the form of a manhole, splice vault, tunnel or pit, and all of these are similar. The exception is that an enclosed space only contains an electrical hazard and is considered enclosed for routine entry. A space can’t be classified as enclosed if any other hazard or abnormal condition is identified. Proper inspection and testing procedures required by the OSHA standards are the only acceptable methods that can be used to reclassify the space as enclosed.

Per 1910.146(b), “confined space” means a space that:
1. Is large enough and so configured that an employee can bodily enter and perform assigned work; and
2. Has limited or restricted means for entry or exit (for example, tanks, vessels, silos, storage bins, hoppers, vaults and pits are spaces that may have limited means of entry); and
3. Is not designed for continuous employee occupancy.

Further, “non-permit confined space” means a confined space that does not contain or, with respect to atmospheric hazards, have the potential to contain any hazard capable of causing death or serious physical harm.

Paragraph 1910.269(e) applies to routine entry into enclosed spaces in lieu of the permit-space entry requirements contained in paragraphs (d) through (k) of 1910.146. If, after the precautions given in paragraphs (e) and (t) of 1910.269 are taken, the hazards remaining in the enclosed space endanger the life of an entrant or could interfere with escape from the space, then entry into the enclosed space shall meet the permit-space entry requirements of paragraphs (d) through (k) of 1910.146. Vented transformer vaults are not included in this section.

Every electric utility industry employee should remember that all spaces mentioned shall be considered permit-required confined spaces until the space has been evaluated and the atmosphere has been found to be safe for entry via proper testing, evaluations and visual inspections.

Per 1910.146(c)(5)(i)(A), an employer whose employees enter a permit space need not comply with paragraphs (d) through (f) and (h) through (k) of 1910.146, provided that the employer can demonstrate that the only hazard posed by the permit space is an actual or potential hazardous atmosphere.

Continuous ventilation and air monitoring may provide safe entry conditions relative to atmosphere. If ventilation will provide a safe entry condition, it is permissible for employees to enter and work. Even though the standard only requires periodic checks on atmosphere, I suggest constant air monitoring while entry is made as well as while work is in progress in the space.

Other hazards – such as converging floors or troublesome equipment – must be dealt with by other means, and usually are handled by a permit-required space procedure.

Training and Signage
All employees entering a space must be trained and authorized to enter it. Training must be provided by the employer prior to the employee entering the space. All other requirements for atmospheric checks are the same for all spaces.

With the publication of the new 1910.269 final rule, a major change has occurred with regard to 1910.269(e). In the old version of the standard, the attendant was able to enter a space for short durations in routine operations and conditions, but not during an emergency or when abnormal conditions were present. Now, under the new rule, the attendant may never enter the space. This mirrors the 1910.146 requirement.

A written plan for permit-required spaces must be used. Entry permits are issued to entry supervisors, and permits can be revoked and declared ended by an entry supervisor at any time.

If permit-required spaces are present in workplaces, they have to be marked as such in order to inform employees. Permit-required spaces must be labeled with danger words to warn employees of the hazards of the permit-required confined spaces.

Paragraph 1910.146(c)(2) states that “[i]f the workplace contains permit spaces, the employer shall inform exposed employees, by posting danger signs or by any other equally effective means, of the existence and location of and the danger posed by the permit spaces. Note: A sign reading DANGER – PERMIT-REQUIRED CONFINED SPACE, DO NOT ENTER or using other similar language would satisfy the requirement for a sign.”

Under 1910.269(e), however, placarding and signage are not required. The training of 1910.269(a)(2) qualified employees requires the employees to recognize that all spaces should be considered and inspected before reclassifying the space as enclosed.

Rescue and Recovery Standards
When dealing with the requirements for rescue and recovery from any space, the following standards apply:

An employer who designates rescue and emergency services, pursuant to paragraph (d)(9) of this section, shall:

Evaluate a prospective rescuer’s ability to respond to a rescue summons in a timely manner, considering the hazard(s) identified;

Note to paragraph (k)(l)(i): What will be considered timely will vary according to the specific hazards involved in each entry. For example, §1910.134, Respiratory Protection, requires that employers provide a standby person or persons capable of immediate action to rescue employee(s) wearing respiratory protection while in work areas defined as IDLH atmospheres.

Select a rescue team or service from those evaluated that:

Has the capability to reach the victim(s) within a time frame that is appropriate for the permit space hazard(s) identified.

Is equipped for and proficient in performing the needed rescue services.

Paragraph 1910.269(e)(3), “Rescue equipment,” states that “[e]mployers shall provide equipment to ensure the prompt and safe rescue of employees from the enclosed space.” The provisions stated in 1910.146 should be considered by employers when meeting this requirement.

Options and Obligations
As employees in the electric utility workplace, we have to deal with enclosed and permit-required spaces. Company policies and OSHA standards dictate the required training needed to keep employees safe. Employers must train employees about how to identify spaces, and employees must follow the training.

The industry does have options to consider when deciding to use either type of procedure. OSHA’s General Duty Clause requires the employer to identify known hazards in the workplace and to provide training, tools and PPE to mitigate the hazards associated with the task. Regardless of which procedure your company uses, make certain that employees follow the training they received and that no steps are omitted – this will help assure that no employee suffers injury, illness or loss of life in any space.

About the Author: Danny Raines, CUSP, safety consultant, distribution and transmission, retired from Georgia Power after 40 years of service and opened Raines Utility Safety Solutions LLC, providing compliance training, risk assessments and safety observation programs. He is also an affiliate instructor at Georgia Tech Research Center OSHA Outreach in Atlanta. For more information, visit

Safety Management, Worksite Safety, Voice of Experience

Danny Raines, CUSP

Danny Raines, CUSP, is an author, an OSHA-authorized trainer, and a transmission and distribution safety consultant who retired from Georgia Power after 40 years of service and now operates Raines Utility Safety Solutions LLC.