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.

February 15, 2017

Mr. Ken Fegley
Process Safety Engineer
Air Products and Chemicals, Inc.
7201 Hamilton Boulevard
Allentown, Pennsylvania 18195-1501

Dear Mr. Fegley:

Thank you for your letter to the Occupational Safety and Health Administration (OSHA). This letter constitutes OSHA’s interpretation only of the requirements referenced below and may not be applicable to any question not included in your original correspondence. Your inquiry is related to coverage of the Process Safety Management Standard (PSM) to certain operations at your and an adjoining facility. Specifically, you requested clarification of whether the process scenario you described is covered by the PSM standard.

Your questions are paraphrased and our response follows.

Scenario: We would like an interpretation regarding the definition of a process, the process boundaries, and the term "on site in one location." In this scenario, Employer A owns and operates a facility, located on Employer B’s property, which produces an HHC (hydrogen gas) but contains less than the threshold quantity (TQ) of 10,000 pounds. The hydrogen leaves this facility and is delivered to Employer B by a pipeline, entirely on Employer B’s property, that is owned and maintained by Employer B (not regulated by DOT). Engineering controls are used to prevent material from returning to the hydrogen generation facility through this pipeline, and ownership of the piping and the hydrogen changes at the fence between Employer A and Employer B’s units. Employer A also maintains a supplemental supply system at a separate, “non-contiguous,” and “geographically remote” (to the extent that all separation distances required by NFPA 55 are met or exceeded) facility located within Employer B's facility that provides hydrogen to (but cannot receive material from) this pipeline. The supplemental supply also contains less than the TQ. Only by combining the inventories of the facilities, the pipeline and Employer B's process can the TQ be exceeded.

Question 1: Would this activity be considered a process covered by the PSM standard and which employer would be responsible for complying with PSM?

Response: YesOSHA defines a process at 29 CFR 1910.119(b) - Process means any activity involving a highly hazardous chemical including any use, storage, manufacturing, handling, or the on-site movement of such chemicals, or combination of these activities. For purposes of this definition, any group of vessels which are interconnected and separate vessels which are located such that a highly hazardous chemical could be involved in a potential release shall be considered a single process.

For the scenario you describe, Employer A and Employer B are two separate employers, however the hydrogen generator, owned by Employer A, is located on Employer B premises. The Employer A hydrogen generator feeds directly to Employer B’s process. Employer B appears to have a quantity above the threshold 10,000 pounds within their facility property taking into account the process, hydrogen generator and onsite storage. As stated in the Federal Register link below, coverage is only excluded where the HHC threshold would be met by aggregating all amounts in interconnected or co-located vessels but some of the amounts needed to meet the threshold quantity are outside of the perimeter of the employer’s facility. In this case, all of the hydrogen inventories are located within employer B’s facility property and hence are contiguous. OSHA interprets “on site in one location” to mean that coverage extends to vessels within contiguous areas controlled by an employer or group of affiliated employers. Therefore, the extent to which each affiliated employer develops a PSM program may be a business or contractual decision determined by the employers. OSHA will evaluate the PSM program and employee exposures as whole, and either or both employers could have responsibilities under OSHA’s PSM standard. Below are some relevant OSHA Letters of Interpretation / Federal Register Postings:

“Limits of a covered process”: http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=22361

“Colocation of HHC containers”: http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=29324

“On site in one location”: https://www.osha.gov/FedReg_osha_pdf/FED20070607.pdf

Question 2: No definition of the term “geographically remote” (as related to Normally Unoccupied Remote Facilities (NURF)) is offered in 29 CFR 1910.119(b). Does a facility that meets or exceeds the required separation distances specified in NFPA Code meet this requirement?

Response: No - Normally unoccupied remote facility is defined at 29 CFR

1910.119(b) — "Normally unoccupied remote facility" means a facility which is operated, maintained or serviced by employees who visit the facility only periodically to check its operation and to perform necessary operating or maintenance tasks. No employees are permanently stationed at the facility. Facilities meeting this definition are not contiguous with, and must be geographically remote from all other buildings, processes, or persons. A covered process is exempt if it is NOT normally occupied as indicated in the following letter of interpretation: 05/29/1998 -- PSM Standard exemption for "Normally Unoccupied Remote Facilities" (water treatment plant). http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=22592

In addition, the process must not be contiguous to the plant site AND must be geographically remote from all other buildings, processes or persons. The intent is to ensure that employees are isolated from the hazards of the NURF process. Geographically remote, when used in context of normally unoccupied and remote, means that any incident including catastrophic release, fire or explosion in the “remote” location could not affect or impact any buildings, equipment, property or employees at the plant site. Generally, this distance is much greater than the separation distances listed in NFPA standards.

The following letters of interpretation include descriptions of the characteristics OSHA expects in a facility claiming the normally unoccupied and remote facility exemption:

“Determination of NURF Status”: http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=25058


Thank you for your interest in occupational safety and health. We hope you find this information helpful. OSHA sets requirements by statute, standards, and regulations. Our letters of interpretation do not create new or additional requirements but rather explain these requirements and how they apply to particular circumstances. This letter constitutes OSHA's interpretation of the requirements discussed. From time to time letters are affected when OSHA updates a standard, a legal decision impacts a standard, or changes in technology affect an interpretation. To assure that you are using the correct information and guidance, please consult OSHA's website at https://www.osha.gov. If you have further questions, please contact the Office of Chemical Process Safety and Enforcement Initiatives at (202) 693-2341.



Thomas Galassi, Director

Directorate of Enforcement Programs