UPDATED on 5/31/11 to answer some specific questions I received over the holiday weekend…Scenario: A process that is covered under PSM/RMP (a toxic liquefied gas under pressure) is in very close proximity to a propane system that is used solely as an on-site fuel. The propane system had always been exempted using the PSM exemption of materials used solely as a fuel and the Fuels Regulatory Relief Act under RMP.
See updates at the end of this post regarding a specific question on Ammonia Refrigeration processes…
The existing covered process was recently expanded and this expansion was built in the only available real estate, which was the “buffer” for the propane tank and vaporizer. The propane is used to fill cylinders for cutting torches, forklifts, and other mobile equipment. It can also be used as an emergency back-up fuel for a boiler. However, we now have a propane tank within 10′ from the process building (fire code issues and 1910.110) and the expansion was built around the existing propane pipe and unloading spot (facility siting and 1910.110(b)(15) issues)
But the debate is… is the LPG process now REQUIRED to be covered under PSM/RMP because of the definition of “process”
…. 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.
Here are a couple of other key items that I feel influenced my decision:
- There is no blast wall or UL/FM rated fire wall separating the LPG tank from the existing covered process
- 20,000 gallon LPG tank is within 20′ of the closest “day tank” that is part of the existing covered process
- the new process building ventilation intake louvers are at ground level and within 10′ of the LPG tank and the vaporizer skid
- a 3″ LPG pipe(s) runs through the new expanded process building and in some spots runs side by side the pipe containing the existing HHC
Other than being the worst design I have ever seen, the LPG system is NOW a “Covered Process” because of the “co-location” in that a LPG incident could impact the existing covered process.
Is the “hydrocarbon used as a fuel” exemption is trumped and the co-location requirement takes precedence?
If we were talking about another “toxic” HHC the answer may be different as there are not a lot of scenario’s where a “toxic” HHC can have a direct impact on the existing integrity of covered process (although it could have an impact on the safe operations if the toxic could impact worker presence). But a flammable liquid or gas can have a huge impact on an existing process via vapor cloud explosion, gas explosion, jet fire, etc.
So be careful where you install your flammable tanks (liquids and gases) even when they will be BELOW THRESHOLDS, as they may become part of your existing covered process. Also, be sure to consider flammable tanks and process locations when an existing process is expanding or moving.
5/31/11 UPDATE :
Over the holiday weekend I received an e-mail from a LinkedIn SAFTENG Member as well as one of my active clients asking some very specific questions about “co-location” and “interconnected” and needing regulatory evidence of my position above. Normally I am quick to paste the OSHA LOI and CPL language to support my position(s), but in the post above I forgot to do this, so here is the regulatory language to support my position on “co-location” and “interconnected”. I have highlighted the key points in the EPA and OSHA language – the highlighting is NOT by OSHA or EPA, it is by me! The language below should support my position above, as well as answer the ammonia refrigeration questions about two different processes on site and both are below the threshold – does the site aggregate the amounts?
Answers from EPA:
Under 40 CFR Part 68, if multiple processes at a stationary source contain the same regulated substance, must the amounts of the substance in the individual processes be aggregated to determine whether a threshold is exceeded?
No. Applicability of the risk management program requirements is based upon the presence of more than a threshold quantity of a regulated substance in a process at a stationary source (40 CFR §68.10(a)). The quantity present is evaluated on a process-by-process basis. It is important to note, however, that multiple, separate vessels located such that both could potentially be involved at one time in an accidental release are considered to be a single process (40 CFR §68.3). The owner or operator of a stationary source will need to make a reasonable determination as to whether two or more vessels may be involved in the same accident. The owner or operator should be able to document the decision that the individual vessels do or do not constitute a single process. If the threshold is not met for a process and thus not subject to part 68, the process is still subject to Section 112(r)(1), the general duty clause.
What is the definition of “process”?
Process, as defined at 40 CFR §68.3, means any activity involving a regulated substance, including any use, storage, manufacturing, handling, or on-site movement of such substances, or combination of these activities. Any group of vessels that are interconnected, or separate vessels that are located such that a regulated substance could be involved in a potential release, is considered a single process. The owner or operator of the stationary source must make a reasonable determination as to whether two or more vessels may be involved in the same accident, or whether a release from one vessel may be anticipated to lead to a release from another. The owner/operator should document his decision as to whether the individual vessels do or do not constitute a single process.
How far apart do separate vessels have to be to be considered different processes?
There is no hard and fast rule for how great this distance should be before you do not need to consider the vessels as part of one process. Two vessels at opposite ends of a large warehouse room might have to be considered as one process if the entire warehouse or room could be engulfed in a fire. Two vessels separated by the same distance out of doors might be far enough apart that a fire affecting one would be unlikely to spread to the other. You may want to consult with your local fire department. You should then use your best professional judgment. Ask yourself how much of the regulated substance could be released if the worst happens (you have a major fire, an explosion, a natural disaster).
Q. I have a tank with more than 10,000 pounds of propane. I use the propane to heat the offices. The propane is not subject to PSM or the risk management program rule. The tank, however, is close to equipment that has chlorine above the applicable threshold and is subject to OSHA PSM and Program 3. Is the [propane] tank considered part of the chlorine process?
A. If a fire or explosion in the propane tank could cause a release of chlorine or other regulated substances or interfere with mitigation of such a release, the tank is considered part of the process. When you do your PHA for the process, you must evaluate how the propane tank could cause a release of chlorine and determine what steps may be needed to prevent such releases.
Source: http://www.epa.gov/sites/production/files/2013-11/documents/cd-chap-07.pdf
From OSHA LOI’s
Source: https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=21406
Question 1: What criteria are used to establish a “remote distance” between processes which potentially may be covered by the PSM Standard?
Reply: When processes are in close proximity to each other such that an incident in one process could involve the potential release of a highly hazardous chemical (HHC) in another process, these processes are considered to be a single process (See the definition of process at 1910.119(d)). Processes which are not in close proximity are considered to be at a remote distance. Federal regulations, or national consensus standards and other criteria acceptable to OSHA, that provide at least equal safety and health to employees in the workplace, may be used to determine whether one process is at a remote distance from another process. For example, with respect to liquid HHC’s, where a dike built around a liquid storage vessel to fully contain released materials, is used to prevent interaction with another vessel outside the dike and neither vessel by itself contains a threshold quantity, then this physical barrier would be considered acceptable in making the two vessels remote from each other. This is set forth in the preamble to the PSM standard, at the bottom half of column two on page 6372 of the Federal Register, a copy of which is enclosed for your use.
Question 5: Would the PSM standard apply to the following scenario? A storage area involves a flammable gas located a remote distance from another storage area involving a flammable gas and each area contains less than the threshold quantity. Each storage area is a storage bank which has independent plumbing and which is used for repackaging into containers in other areas. In one location the plumbing (1/2″ diameter) of each of the two totally independent systems comes into close proximity to each other.
Reply: The two processes described may be considered a single process (See the reply to question 1). When these two processes are considered a single process and collectively contain 10,000 pounds (4535.9 kgs) or greater amounts of flammable gases, the PSM standard applies. If one of the storage areas including the contents of equipment connected to it contains 10,000 pounds (4535.9 kgs) of flammable gas, then the PSM standard applies.
To assist you in determining when the storage and handling of HHCs are segregated to the point their amounts do not need to be aggregated, OSHA has stated that engineering controls (i.e. sprinkler systems, self-closing fire doors. etc.), and administrative controls, (i.e., operating procedures) used to prevent and mitigate a catastrophic release of a covered HHC may NOT be used to determine the extent of a process as defined in paragraph 1910.119(b). Note: for non-interconnected equipment, “passive mitigation” may be used to limit the extent or the boundaries of a covered process. Further, the employer must determine if other aspects of the stipulated covered process are also part of the covered process. If an aspect of the covered process could affect a release of an HHC or interfere with the mitigation of the consequences of a release from the covered process, then the aspect being considered would be part of the covered process. For example, if a fire in a part of the warehouse (aspect under consideration) which stores non-HHCs could spread to the stipulated covered process and affect a release of an HHC, then the aspect under consideration would be part of the covered process.
Each and EVERY facility WILL BE DIFFERENT! Even “identical processes” at different facilities will need to be evaluated on their own merits, as facility siting can influence what is covered and what is not, and often times what surrounds these :identical skid units” is what can cause one unit to be covered and the exact same skid unit at a sister site NOT be covered. Remember, when doing your evaluation it is IMPERATIVE that the facility look at what is OUTSIDE of the questionable process area that could impact the process in question! I have seen “skid units” that are identical systems have completely different battery limits based on what the individual facility was doing around the process. It is my opinion that four separate processes containing a High Vapor Pressure HHC (e.g. Ammonia) could easily be covered even though they are all below the threshold AND they are NOT interconnected simply by the fact that in the middle of these four processes is the facility’s bulk propane storage tank. A release of this flammable hgas could lead to an explosion and the explosion could cause a release of Ammonia. (NOTE: this release does not have to be a Worst-Case release, ANY amount released would make the ammonia processes covered by “co-location”.) Here is the other side of this coin…
If the facility hires an Vapor Cloud Explosion (VCE) expert (not me!) such as Baker Risk or Unwin Company to perform an analysis and this analysis documented that a propane release and explosion would NOT impact the Ammonia systems becuase they are “REMOTE” enough from the propane, then the facility would have DOCUMENTATION to support their position that the ammonia systems are NOT a covered process (KEEPING IN MIND the CAA and OSHA General Duty Cluases of course). Also remember, two toxic HHC’s have a much less likelihood of impacting each other, UNLESS they are reactive to each other and a release from one of the processes could DIRECTLY cause a release from the other. The BIGGER and EASIER scenario is when dealing with flammables and vapor cloud explosions that can cause structural damage. EVEN when the flammable liquid tank is diked properly (as noted in one of the EPA statements above), but a study shows there is enough heat generated by a pool fire in that dike that would heat up your ammonia tanks and cause your Ammonia PSV to lift and thus release Ammonia, the Ammonia process WOULD THEN be a covered process. Also, Ammonia tanks CAN B.L.E.V.E. and this needs to be considered as well. So with flammable liquids, a simple dike may NOT be enough to say the ammonia is NOT covered if the ammonia tank is close enough (facility siting) to be impacted by a pool fire in the flammable dike.
As you can see, I could go on for days with different scenarios. Each facility has to be evaluated on it’s INDIVIDUAL situation. I usually advise facility’s to contact their Local OSHA office and ask for guidance, but in the case of determining “battery limits” you will ALSO want to discuss your situation with EPA as often times I have gotten entirely different answers. You would not want to follow one set of guidance and have the other regualtory agency not agree and end up citing you. Remember, some OSHA area offices have NOT accepted EPA’s RMP audits as a 3-year audit and vide versa, so the two agencies do NOT always see eye to eye on compliance matters!!!