- Standard Number:
OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.
April 15, 2014
Mr. Edwin G. Foulke, Jr.
Fisher & Phillips, LLP
1075 Peachtree Street, NE
Atlanta, GA 30309
Dear Mr. Foulke:
Thank you for your March 21, 2013, letter to the Occupational Safety and Health Administration (OSHA), regarding permit-required confined spaces. We have also received your July 12, 2013 follow-up letter that clarifies the original. Your letter was referred to OSHA's Directorate of Enforcement Programs (DEP) for response. We apologize for the delay in our response. We have paraphrased your questions, and our replies follow. This letter constitutes OSHA's interpretation only of the requirements discussed, and may not be applicable to any questions not delineated within your original correspondence.
Scenario: A company uses a centralized confined space monitoring system comprised of a control center that consolidates all monitoring, observations, atmospheric testing and communications functions. The control center is manned by trained technicians. Oxygen content, flammable gases and vapors, and potential toxic air contaminants are continuously monitored within the control center, with results available in real time on display screens. The testing involves a short delay as the air sample passes through the tubing to the detector, which is located outside the permit space. This delay is approximately one second for every two meters of detector tubing. For example, a tubing length of ten meters will result in a five second delay. Employees or their representatives can observe the testing results within the control center or by communicating through intercom with the control center. The system is designed to be used with a Field Supervisor, who remains in contact with the operator in the control room, and can communicate with entrants. The Field Supervisor also prevents unauthorized entry or rescue by unqualified employees, and performs system checks and adjustments, such as bump tests or repositioning of cameras.
Question 1: Does a system, such as the one described above that displays the monitoring results remotely, comply with the testing requirements at §1910.146(c)(5)(ii)(C)?
Response 1: Paragraph (c)(5) of the standard provides alternate entry requirements for permit-required confined spaces where the only hazard within the space is an atmospheric hazard that can be controlled through continuous forced air ventilation, among other requirements. This response assumes that the space in question meets all of the application limitations of paragraph (c)(5). The OSHA standard at §1910.146(c)(5)(ii)(C) states:
Before an employee enters the space, the internal atmosphere shall be tested, with a calibrated direct-reading instrument, for oxygen content, for flammable gases and vapors, and for potential toxic air contaminants, in that order. Any employee who enters the space, or that employee's authorized representative, shall be provided an opportunity to observe the pre-entry testing required by this paragraph.
Before entering a permit space using the alternate entry procedures in paragraph (c)(5), the standard requires testing the atmosphere within the space using direct-reading instruments, meaning instruments where the results of the test are available in real-time, or near real-time (see the OSHA Safety Topics webpage on Direct Reading Instruments at https://www.osha.gov/SLTC/directreadinginstruments/. Test or monitoring equipment with results displayed at a central location would meet the requirement for pre-entry testing using- a direct-reading instrument provided there is no or minimal delay between collecting the test sample and display of the results, and minimal travel time is required for the entrant to return to the permit space entry point after witnessing the pre-entry tests, such that a hazardous atmosphere could not develop in the time between the entrant observing the pre-entry test and the time entry began.
Question 2: Does a system, such as the one described above that displays the monitoring results remotely, allow an employer to determine that no hazardous atmosphere exists within the space during entry, as required by §1.910.146(c)(5)(ii)(D)?
Question 3: Does a system, such as the one described above that displays the monitoring results remotely, comply with the testing requirements for periodic testing of the atmosphere, as required by §1910.146(c)(5)(ii)(F)?
Response to Questions 2 and 3: No. The OSHA standard at §1910.146(c)(5)(ii)(D) states:
There may be no hazardous atmosphere within the space whenever any employee is inside the space.
The OSHA standard at §1910.146(c)(5)(ii)(F) states:
The atmosphere within the space shall be periodically tested as necessary to ensure that the continuous forced air ventilation is preventing the accumulation of a hazardous atmosphere. Any employee who enters the space, or that employee's authorized representative, shall be provided with an opportunity to observe the periodic testing required by this paragraph.
The intent of the standard is to detect rising atmospheric levels before they reach a hazardous level. Test equipment with results displayed at a central location would comply with the standard if the potential hazards within the space, and the potential for rapid accumulation of contaminants, could be detected and the conditions communicated to entrants before the atmosphere becomes a hazardous atmosphere. OSHA notes that a delay of five seconds, as described in your scenario, could be fatal in some scenarios.
Scenario: The continuous testing described in the scenario above will automatically trigger an alarm when the sensors detect signs of a hazardous atmosphere exceeding predefined levels. Alarms are triggered at two levels. The first level initiates a flashing light, and the second level initiates an evacuation siren. System operators at the control room may also initiate the siren, or may use the intercom system to warn employees to evacuate. A Field Monitor is also present, but may not be at the entry point to that particular permit space. The system operator may direct the Field Monitor to notify the employees to evacuate a specific space in the event of an emergency.
Question 4: Does a system, such as the one described above with automatic alarms and manual backup systems, comply with the requirements for hazardous atmosphere detection in §1910.146(c)(5)(ii)(G)?
Response 4: The OSHA standards at §1910.146(c)(5)(ii)(G) and (G)(1) state:
If a hazardous atmosphere is detected during entry:
(1) Each employee shall leave the space immediately;
Paragraph (c)(5)(ii)(F) requires periodic testing to detect any hazardous atmosphere within the permit space during entry under alternate entry procedures in paragraph (c)(5). If the testing required by (c)(5)(ii)(F) detects a hazardous atmosphere, paragraph (c)(5)(ii)(G)(1) requires entrants to leave the space immediately. Therefore, if the periodic testing detects a hazardous condition, or indicates that the ventilation is not preventing accumulation of a hazardous atmosphere, the system described above must be capable of alerting the entrants quickly enough so that each employee will be able to evacuate immediately. The intent of the provision is to prevent employee exposure to any hazardous atmosphere.
Scenario: The test and monitoring system described above continuously measures the atmosphere within the permit space and stores the data in an internal logger, in addition to being stored by the system within the control room.
Question 5: Does a system, such as the one described above that stores data from the sensors, allow an employer to comply with §1910.146(c)(5)(i) and (c)(5)(i)(C)?
Response 5: The OSHA standards at §1910.146(c)(5)(i) and (c)(5)(i)(C) state:
An employer whose employees enter a permit space need not comply with paragraphs (d) through (f) and (h) through (k) of this section, provided that:
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(C) The employer develops monitoring and inspection data that supports the demonstrations required by paragraphs (c)(5)(i)(A) and (c)(5)(i)(B) of this section;
The OSHA standard does not specify the means of collecting the data used to determine if the hazards within a permit space may be controlled by continuous forced air ventilation. Analysis of data collected using the system described above could assist in complying with §1910.146(c)(5)(i) and (c)(5)(i)(C).
Question 6: Does a system, such as the one described above that stores data from the sensors, comply with §1910.146(c)(5)(ii)(H) if the system operator has a unique username and password provided to the system upon logging in? The login would serve as the system operator's signature.
Response 6: No. The OSHA standards at §1910.146(c)(5)(ii)(H) states:
The employer shall verify that the space is safe for entry and that the pre-entry measures required by paragraph (c)(5)(ii) of this section have been taken, through a written certification that contains the date, the location of the space, and the signature of the person providing the certification. The certification shall be made before entry and shall be made available to each employee entering the space or to that employee's authorized representative.
The intent of the standard is that an employer would verify conditions immediately prior to entry, and that the employer or his or her representative would verify that all precautions, including pre-entry testing, are in place and functional immediately prior to entry. An initial login does not meet the intent of the standard because it does not certify that the system operator has both actively viewed the testing results immediately before entry begins, and also certified that the required pre-entry precautions are in place immediately before entry. Additionally, your letter does not specify if the login identifies the date and location of the permit space being tested and entered, as required by the standard.
Question 7: Does a system, such as the one described above, comply with some of the required elements for implementing a permit space program, specifically §§1910.146(d)(1), (d)(2), (d)(3)(i), and (d)(3)(ii)?
Response 7: Provisions §1910.146(d)(1) through (d)(3)(i) state:
(d) Permit-required confined space program (permit space program). Under the permit space program required by paragraph (c)(4) of this section, the employer shall:
(d)(1) Implement the measures necessary to prevent unauthorized entry;
(d)(2) Identify and evaluate the hazards of permit spaces before employees enter them;
(d)(3) Develop and implement the means, procedures, and practices necessary for safe permit space entry operations, including, but not limited to, the following:
(d)(3)(i) Specifying acceptable entry conditions;
The assigned duties of the Field Supervisor, in combination with the ability to identify unauthorized entrants from the control room, would enable the employer to comply with the requirement to implement measures to prevent unauthorized employee entry, if the Field Supervisor is able to reach unauthorized persons before they enter the permit space or interfere with an entry in progress. As to identifying and evaluating the hazards of permit spaces before entry, the employer must determine the potential hazards within the space and establish, through recognized good engineering practices, a safe condition for entry based on the hazards identified. The ability of the system to test the atmosphere could assist the employer in identifying potential hazardous atmospheres within the space.
Question 8: Does a system, such as the one described above comply with the requirements to provide testing and monitoring equipment, and communications equipment for permit space entry, as required by §1910.146(d)(4)(i) and (d)(4)(iii)?
Response 8: Paragraph §1910.146(d)(4)(i) states:
(d)(4) Provide the following equipment (specified in paragraphs (d)(4)(i) through (d)(4)(ix) of this section) at no cost to employees, maintain that equipment properly, and ensure that employees use that equipment properly:
(d)(4)(i) Testing and monitoring equipment needed to comply with paragraph (d)(5) of this section;
Paragraph §1910.146(d)(4)(iii) states:
Communications equipment necessary for compliance with paragraphs (h)(3) and (i)(5) of this section;
There is not enough information to make this determination. Factors that could affect the performance of the testing and monitoring equipment include arrangement of the detection sensors, characteristics of the substance being tested, size of the space, and internal configuration of the space. Similarly, size and configuration of the space, location of speakers, and interference from ambient noise are all factors that could affect communication with this system.
Question 9: Does a system, such as the one described above comply with the requirements to evaluate permit space conditions before entry, monitor the conditions during entry, and for entrants or their authorized representatives to have the opportunity to observe testing, as required by §1910.146(d)(3)(ii), (d)(5)(i), (d)(5)(ii), (d)(5)(iv), (d)(5)(v) and (d)(5)(vi)?
Response 9: Paragraphs §1910.146(d)(3)(ii), (d)(5)(i), (d)(5)(ii), (d)(5)(iv), (d)(5)(v) and (d)(5)(vi) state:
(d)(3)(ii) Providing each authorized entrant or that employee's authorized representative with the opportunity to observe any monitoring or testing of permit spaces;
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(d)(5) Evaluate permit space conditions as follows when entry operations are conducted:
(d)(5)(i) Test conditions in the permit space to determine if acceptable entry conditions exist before entry is authorized to begin, except that, if isolation of the space is infeasible because the space is large or is part of a continuous system (such as a sewer), pre-entry testing shall be performed to the extent feasible before entry is authorized and, if entry is authorized, entry conditions shall be continuously monitored in the areas where authorized entrants are working;
(d)(5)(ii) Test or monitor the permit space as necessary to determine if acceptable entry conditions are being maintained during the course of entry operations; and
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(d)(5)(iv) Provide each authorized entrant or that employee's authorized representative an opportunity to observe the pre-entry and any subsequent testing or monitoring of permit spaces;
(d)(5)(v) Reevaluate the permit space in the presence of any authorized entrant or that employee's authorized representative who requests that the employer conduct such reevaluation because the entrant or representative has reason to believe that the evaluation of that space may not have been adequate;
(d)(5)(vi) Immediately provide each authorized entrant or that employee's authorized representative with the results of any testing conducted in accord with paragraph (d) of this section.
Note: Atmospheric testing conducted in accordance with appendix B to §1910.146 would be considered as satisfying the requirements of this paragraph. For permit space operations in sewers, atmospheric testing conducted in accordance with appendix B, as supplemented by appendix E to §1910.146, would be considered as satisfying the requirements of this paragraph.
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There is not enough information to make this determination. See the response to Question 8 for factors that could affect the performance of the testing and monitoring equipment. Allowing employees or their representatives to observe testing at the portal and/or view the test results in real time within the control room as results are being logged would comply with the requirement to provide an opportunity to observe testing and monitoring of the permit space. Re-evaluation of the permit space is required if hazards may be present within the permit space that were not addressed during the evaluation of the space to determine safe entry conditions, and cannot be addressed by the testing functions of the system described.
Question 10: Does a system, such as the one described above, comply with the requirements of §1910.146(d)(6) to provide at least one attendant?
Response 10: The standard permits attendants to monitor more than one permit space. Paragraph §1910.146(d)(6) states:
(d)(6) Provide at least one attendant outside the permit space into which entry is authorized for the duration of entry operations;
NOTE: Attendants may be assigned to monitor more than one permit space provided the duties described in paragraph (i) of this section can be effectively performed for each permit space that is monitored. Likewise, attendants may be stationed at any location outside the permit space to be monitored as long as the duties described in paragraph (i) of this section can be effectively performed for each permit space that is monitored.
Attendants may monitor permit spaces from locations away from the permit space portal. As stated in the preamble to the final rule on Permit-Required Confined Spaces, 58 FR 4462, 4500 (Jan. 14, 1993):
To address the issue of how many spaces an attendant is allowed to monitor, OSHA is including an explanatory note following paragraph (d)(6) to indicate that an attendant can monitor as many spaces as is possible while complying with paragraph (i) of the final rule, which sets forth attendants' duties. The note also indicates that the attendant may be stationed in any position from which he or she can perform the duties required by paragraph (i). The Agency notes that the attendant could be stationed in a control room that allows him or her to monitor entrants remotely. Electronic monitors, television monitors, public address systems, and barricades could be used to assist the attendant in performing duties required under paragraph (i).
The combination of a Field Supervisor and a technician within the system control room may meet the requirement to provide at least one attendant for each permit space into which entry is authorized, if the Field Supervisor and control room technician can effectively perform the duties of an attendant required by §1910.146(i).
Question 11: Does a system, such as the one described above, and used in conjunction with the Field Supervisor as described above, comply with the requirements for attendant duties related to entrant monitoring, communication, and access control for permit-required confined spaces, as specified in §1910.146(i)?
Response 11: Yes. Paragraph §1910.146(i) states, in part:
1910.146(i) Duties of attendants. The employer shall ensure that each attendant:
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(3) Continuously maintains an accurate count of authorized entrants in the permit space and ensures that the means used to identify authorized entrants under paragraph (f)(4) of this section accurately identifies who is in the permit space;
* * * * *
(5)Communicates with authorized entrants as necessary to monitor entrant status and to alert entrants of the need to evacuate the space under paragraph (i)(6) of this section;
(6)Monitors activities inside and outside the space to determine if it is safe for entrants to remain in the space and orders the authorized entrants to evacuate the permit space immediately under any of the following conditions;
(i)If the attendant detects a prohibited condition;
(ii)If the attendant detects the behavioral effects of hazard exposure in an authorized entrant;
(iii)If the attendant detects a situation outside the space that could endanger the authorized entrants; or
(iv)If the attendant cannot effectively and safely perform all the duties required under paragraph (i) of this section;
(7)Summon rescue and other emergency services as soon as the attendant determines that authorized entrants may need assistance to escape from permit space hazards;
(8)Takes the following actions when unauthorized persons approach or enter a permit space while entry is underway:
(i)Warn the unauthorized persons that they must stay away from the permit space;
(ii)Advise the unauthorized persons that they must exit immediately if they have entered the permit space; and
(iii) Inform the authorized entrants and the entry supervisor if unauthorized persons have entered the permit space;
(10) Performs no duties that might interfere with the attendant's primary duty to monitor and protect the authorized entrants.
The system described allows remote tracking of entrants, remote activity monitoring within the space, observation of activities outside the space, and communication with entrants, satisfying the OSHA requirements in (d)(3), (d)(5), (d)(7) and (d)(8), provided the system can assure that the attendant is not required to perform duties in the control room that would interfere with their primary duty to monitor and protect authorized entrants, as required by §1910.146(i)(10).
Thank you for your interest in occupational safety and health. If you have any further questions, please feel free to contact the Office of General Industry Enforcement at (202) 693-1850.
Thomas Galassi, Director
Directorate of Enforcement Programs