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• Standard Number: 1910.119; 1910.119(b)

February 16, 2005

Mr. Ty J. Smith
Lesair Environmental, Inc.
10394 W. Chatfield Ave., Ste. 100
Littleton, CO 80127

Dear Mr. Smith:

Thank you for your letter dated February 24, 2004 (received in our office May, 25, 2004) to the Occupational Safety and Health Administration's (OSHA's) Directorate of Enforcement Programs (DEP). Our response is based on information you provided in your letter. You have issues regarding OSHA's Process Safety Management of Highly Hazardous Chemicals; Explosives and Blasting Agents standard (PSM), 29 CFR 1910.119. Please beaware that this response may not be applicable to any question or situation not delineated within your original correspondence. Your specific issues are related to the application of OSHA's requirements related to normally unoccupied remote facilities (NURF) at natural gas processing plants (gas plant).

Scenario 1: The following facts provided the basis for Question 1:

  • Facility A is a natural gas plant;
  • Facility A processes sour natural gas from natural gas wellsin the area;
  • Under previous ownership, Facility A was the central facility for smaller surrounding operations and thus had a two-room office and bathroom facility. Employees were considered to be permanently stationed at Facility A;
  • Under new ownership Facility A undergoes changes:
    1. Facility A is no longer the central facility for the surrounding area;
    2. Facility B becomes the new central natural gas processing facility;
    3. Facility B is located about 5 miles from Facility A;
    4. Facility B is where the employees are now considered permanently stationed, and there are offices for operating staff, a meeting room, bathroom facilities, etc.;
    5. Facility A is now used as a "compressor station," the sour gas at Facility A is compressed and sent by pipeline to Facility B (the gas plant) for processing;
    6. Facility A is still used to dehydrate the natural gas (removing water vapor from the gas) and to store any hydrocarbon liquids and water that may separate from the natural gas;
    7. Under the new operating situation, Facility A has employees that visit the facility everyday for 1.5 to 2 hours to perform normal servicing or maintenance;
    8. Additionally, on a less frequent basis, say monthly, employees spend additional time at Facility A to perform tasks associated with more extensive maintenance and equipment repairs;
    9. The personnel report to work at Facility B and attend safety meetings, etc. at Facility B; and
    10. The Facility A office and bathroom are still in place. The structure containing the office and bathroom is not used as a location where employees are permanently assigned but is now used as a convenient bathroom and possible shelter, if necessary.
Question 1: Do Facility A and Facility B qualify for the NURF exemption under the new operating and processing situation described above?

Response 1: There is insufficient information to answer this question. However, we will provide you information which we hope will assist you in determining whether your facilities are exempt from PSM requirements.

First, we assume that Facility A and Facility B each include a process which contains 10,000 pounds or more of flammable gas or flammable liquid — the threshold quantity (TQ) for these substances. If this is correct, then a PSM-covered process exists at both Facility A and Facility B. If a TQ of flammable gas or flammable liquid does not exist in a process at these facilities, then the PSM standard does not apply.

Facility A under the original owner and Facility B under the new owner are covered by PSM because they are gas plants. OSHA covers gas plants under PSM.1 The NURF exemption does not apply in either instance because both facilities have employees permanently stationed at them. One of the criteria listed in the definition of a NURF in the PSM standard2 states that no employees are permanently stationed at the facility.

Based on the information you provided, we cannot determine if, under the new owner, Facility A (New Facility A) would qualify for the NURF exemption. The information you provided shows employees work at New Facility A to perform operations and maintenance activities. This information also establishes that New Facility A is not contiguous with and is geographically remote from all other buildings, processes and persons. However, we cannot determine if employees only visit the site periodically to check operations and to perform necessary operating and maintenance tasks.

To assist you in your determination of whether employees visit the site periodically as required by the NURF exemption, we refer you to a previous letter of interpretation3 issued by OSHA. The NURF subject of this previous interpretation letter had employees at the site for an average of 1.5 man-hours per day and a total of 14.5 man-hours per week. If your employees do not exceed the average on-site times listed in the previous interpretation letter, the New Facility A would be considered a NURF and the exemption would apply.

Scenario 2: The following facts provide the basis for Question 2:

  • A compressor station consists of natural gas compressors; dehydration and hydrocarbon liquid condensation produces water that is stored at the central facility for an area;
  • The facility is associated with numerous natural gas/condensate wells in the area;
  • The facility is a common-point production facility, typical to oil and gas production operations;
  • The facility is used to lower the gathering pipeline pressure and increase the gas pressure enough to transport the gas to the next facility;
  • The facility has a building with telephone, electric power, a bathroom, and a maintenance area;
  • Typically, personnel only spend an hour or two at the facility performing their daily work tasks;
  • Due to the proximity of the facility, personnel use it as a climate-controlled shelter for eating lunch and making phone calls;
  • These personnel have a permanent facility that they are associated with, but the permanent facility is not located as conveniently as this compressor station facility is for taking lunch breaks; and
  • This compressor station does not have employees permanently stationed at it.
Question 2: Is the compressor station facility exempted from PSM requirements due to the NURF exemption?

Response 2: The fact set you provided does not provide sufficient information to determine if the compressor station is a gas plant or is part of a gas plant. If the compressor station is a gas plant or is part of a gas plant, then our Response 1 (above) applies to the situation you describe.

If the compressor station is not a gas plant or part of a gas plant, then it would be an oil/gas production facility, as you stated in the information provided in the scenario to this question. OSHA stated in a memorandum to its Regional Administrators4 that it would not enforce its PSM standards at oil and gas production facilities pending the outcome of an economic analysis with respect to the feasibility of compliance with PSM at these type facilities. When the PSM oil/gas production enforcement issue is resolved, the analysis for determining the applicability of the NURF exemption at oil/gas production facilities, including the subject compressor station and its associated facilities (assuming a TQ of HHC are contained in a covered process), would be the same as the analysis we presented in Response 1 (above).

Thank you for your interest in occupational safety and health. We hope you find this information helpful. OSHA requirements are set by statue, 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 http://www.osha.gov. If you have any further questions, please feel free to contact the Office of General Industry Enforcement at (202) 693-1850.

Sincerely,


Richard E. Fairfax, Director
Directorate of Enforcement Programs

1 FR, Vol. 57, No. 38, 2/24/92, pg. 6371 — PSM Finale Rule Preamble] " ... OSHA disagrees with commenters that gas processing should be excluded from coverage. While OSHA is very concerned with explosions, OSHA is also concerned with fires resulting from releases of highly hazardous chemicals (55 FR at 29150), which as indicated above can occur and clearly endanger employees in the area. Therefore, OSHA believes that gas plants are appropriately covered by the process safety management standard." [emphasis added]. [ back to text ]

2 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. [ back to text ]

3 OSHA Interpretation Letter: 05/29/1998 -- PSM Standard exemption for "Normally Unoccupied Remote Facilities" (water treatment plant). [Found on OSHA's website at — http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=22592. [ back to text ]

4 OSHA Memorandum to Regional Administrators: "Subject: OSHA will not enforce the PSM standard at oil and gas production facilities" dated: 04/11/2000. [ back to text ]

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