You Have a Covered Process? What Are Its Boundaries? WITT O BRIEN S Process Safety Compliance Workshop Houston, Texas October 23, 2018

Transcription

1 You Have a Covered Process? What Are Its Boundaries? WITT O BRIEN S Process Safety Compliance Workshop 1

2 First Managing process safety is always necessary. The need and effort to comply the PSM Standard and the RMP Rule depends. Do you have a covered process or processes at your site? What are the boundaries of those covered processes? 2 Everyone we have ever worked with is accepting if not downright enthusiastic about managing process safety. Likewise, everyone we have ever worked with is no more enthusiastic about complying with the Process Safety Management Standard or the Risk Management Planning Rule than they are about getting a root canal. In part this is because the standards, 29 CFR and 40 CFR 68, are not about managing process risk but about minimizing consequences. In part, though, this is because of their deep seated fear that despite their best efforts, they will never be able to do it well enough to satisfy OSHA or the EPA. Like a root canal, they are sure that compliance is good for them, but if possible, they would really like to minimize its impact. <click> The need to comply depends on whether you have one or more covered processes at your site. <click> The effort required to comply depends a great deal on how big your covered processes are. 2

3 Do you have a covered process? (a)(1)(i) A process which involves a chemical at or above the specified threshold quantities listed in Appendix A to this section; 40 CFR 68.10(a) more than a threshold quantity of a regulated substance in a process, as determined under The two regulations have different lists and even where there is overlap, it doesn t mean the threshold quantity (TQ) is the same. Chlorine, for example, is on both the PSM list and the RMP list. PSM has a TQ of 1500 lbs, meaning that a single ton cylinder exceeds the TQ. RMP has a TQ for chlorine of 2500 lbs, so a single ton cylinder does not exceed the TQ, but two ton cylinders do. 3

4 Flammables (a)(1)(ii) A process which involves a Category 1 flammable gas (as defined in (c)) or a flammable liquid with a flashpoint below 100 F (37.8 C) on site in one location, in a quantity of 10,000 pounds ( kg) or more 4 PSM uses definitions for flammable gases and liquids, and anything that meets one of the definitions is subject to consideration. It doesn t matter what the composition of the liquid or the gas is. RMP, on the other hand, has a specific list of flammable chemicals it is worried about. Both use a TQ of 10,000 lbs for flammables. 4

5 Fuel Exception Except for (a)(1)(ii)(a) Hydrocarbon fuels used solely for workplace consumption as a fuel (e.g., propane used for comfort heating, gasoline for vehicle refueling), if such fuels are not a part of a process containing another highly hazardous chemical covered by this standard 5 It used to be that OSHA made an exception for any fuel. Now they are much more rigid, so the fuel must be a hydrocarbon. Fuel alcohols, for example, no longer qualify for this exception. The RMP regulation originally did not have a fuel exception, but one was added in March 2000: : A flammable substance listed in Tables 3 and 4 of is nevertheless excluded from all provisions of this part when the substance is used as a fuel or held for sale as a fuel at a retail facility. 5

6 Atmospheric storage exception Except for (a)(1)(ii)(b) Flammable liquids with a flashpoint below 100 F (37.8 C) stored in atmospheric tanks or transferred which are kept below their normal boiling point without benefit of chilling or refrigeration. 6 OSHA regretted this exception almost as soon as they promulgated the regulation and tried to interpret it away. In the Meer decision, however, a judge said that the exception stands, unless OSHA wants to go through the rulemaking process to change it. Its been on their regulatory agenda for decades and they still haven t changed it. Regardless, it is important to remember that the atmospheric tank exception only applies to flammable liquids, not to listed toxic chemicals. RMP does not have an exception for storage of flammables in atmospheric tanks. It does make an exception, however, for the storage of gasoline. In (b)(2)(ii), it says: Regulated substances in gasoline, when in distribution or related storage for use as fuel for internal combustion engines, need not be considered when determining whether more than a threshold quantity is present at a stationary source. 6

7 Definitions Atmospheric tank Atmospheric tank means a storage tank which has been designed to operate at pressures from atmospheric through 0.5 p.s.i.g. (pounds per square inch gauge, 3.45 Kpa). 7 Designed doesn t just mean that it is operated at pressures between 0 and 0.5 psig, but that it cannot go outside of that range. Putting a vent that is open to atmosphere is one way to convert a high pressure vessel to an atmospheric tank designed to operate at atmospheric pressure. A conservation vent must have a set point less than 14 in WC to qualify. 7

8 Retail facilities exemption This section does not apply to: (a)(2)(i) Retail facilities 8 OSHA used to base this on 50% of sales being retail sales. Now, OSHA bases this on being in a NAICS classification that is retail by definition. The EPA s exemption for retail facilities is limited to , where it excludes flammable substances held for sale as a fuel at a retail facility. 8

9 Exemption for NURFs This section does not apply to: (a)(2)(iii) Normally unoccupied remote facilities 9 If there is a desk and chair, or a restroom, OSHA won t consider it a NURF. The RMP rule does not make an exemption for NURFs, which makes sense given that they are interested in protecting the environment and the public, which are always present whether or not workers are. 9

10 RMP s ammonia exemption Exemptions. Agricultural nutrients. Ammonia used as an agricultural nutrient, when held by farmers, is exempt from all provisions of this part

11 Appendix A: The 1% rule CHEMICAL name CAS* TQ** Acetaldehyde Acrolein (2-Propenal) Acrylyl Chloride Allyl Chloride Allylamine *Chemical Abstract Service Number. **Threshold Quantity in pounds 11 Anything at less than a 1% wt solution doesn t count. If it is over 1%, it does count, but only the contained amount counts. So, a 10% mixture of acetaldehyde must be considered. If there were 20,000 lbs of this 10% mixture, it would contribute 2,000 lbs toward the TQ. 11

12 Appendix A: The partial pressure rule CHEMICAL name CAS* TQ** Alkylaluminums Varies 5000 Hydrogen bromide *Chemical Abstract Service Number. **Threshold Quantity in pounds 12 There is an exemption to the over 1% rule. If the vapor pressure of the listed compound in the mixture is less than 10 mmhg at the temperature it is used, it doesn t have to be counted toward the TQ. OSHA has found that aqueous mixtures of hydrogen bromide at concentrations below 63% and mixtures of alkylaluminum at any concentration will fall within the partial pressure exemption under all normal handling and storage conditions. 12

13 Appendix A: Anhydrous chemicals CHEMICAL name CAS* TQ** Ammonia, Anhydrous Dimethylamine, Anhydrous Hydrochloric Acid, Anhy Hydrofluoric Acid, Anhy Hydrogen Cyanide, Anhy Methylamine, Anhydrous *Chemical Abstract Service Number. **Threshold Quantity in pounds 13 These six chemicals on the list are described as anhydrous. This means that if they are mixed with water, they are not listed. If they are mixed with anything other than water, then you go back to the 1% rule. 13

14 Appendix A: Listed concentrations CHEMICAL name CAS* TQ** Ammonia solutions (> 44%) Diacetyl Peroxide (> 70%) Ethyl Methyl Ketone Peroxide or Methyl Ethyl Ketone Peroxide (> 60%) Formaldehyde (Formalin) *Chemical Abstract Service Number. **Threshold Quantity in pounds 14 Chemicals on the list that have a mixture concentration called out are only covered when their concentration is greater than the concentration that is called out. The concentrations are all in weight percent. When the concentration is greater than the limit, it is only the contained chemical that counts. For instance, a 10% ammonia solution is not covered, no matter how much you have. On the other hand, a 50% aqueous ammonia solution must be considered. If you had 25,000 lbs of 50% ammonia solution, you would only have 12,500 lb of contained ammonia, which by itself would be less than the TQ. Formaldehyde does not list a concentration. Instead, it is called out as Formalin, which OSHA has defined to mean a solution of formaldehyde that is greater than 37%. 14

15 Appendix A: Listed concentrations CHEMICAL name CAS* TQ** Hydrogen Peroxide (> 52%) Nitric Acid (> 94.5%) Oleum (65% to 80%) Peracetic/Peroxyacetic Acid (> 60% acetic acid) Perchloric Acid (> 60%) *Chemical Abstract Service Number. **Threshold Quantity in pounds 15 OSHA refers to 11 HHCs as having minimum listed concentrations. I ve identified nine. One issue is that there are two pairs of chemical names where each name is listed even though they are referring to the identical substance: Ethyl Methyl Ketone Peroxide and Methyl Ethyl Ketone Peroxide, and Peracetic Acid and Peroxyacetic Acid. That brings it down to nine. But then, I ve also listed Formaldehyde (Formalin), which must be at a concentration greater than 37% to be covered. So what is the final discrepancy? 15

16 Appendix A: Cellulose Nitrate CHEMICAL name CAS* TQ** Cellulose Nitrate (concentration > 12.6% nitrogen) *Chemical Abstract Service Number. **Threshold Quantity in pounds 16 The chemical with a listed concentration that should not be considered a mixture concentration is cellulose nitrate. In the case of cellulose nitrate, the 12.6% nitrogen refers to the degree of nitration, not the concentration of cellulose nitrate. Moderately nitrated cellulose, that is, with greater than 12.6% nitrogen is covered under PSM, unless it is in a solution that is less than 1% cellulose nitrate or has a partial pressure less than 10 mm Hg. 16

17 How does the RMP rule do it differently? Same 1% rule for toxics (b)(1) Same partial pressure rule for toxics (b)(1) 1% rule for flammable mixtures: > 1% of a regulated flammable and FP < 73 F Only 3 toxic substances identified as anhydrous Only 4 toxic substances with listed concentrations 17 OSHA s 1% rule and partial pressure rules are fairly recent interpretations, and they acknowledge that they lifted them straight from the RMP rule. The EPA approaches flammability by list rather than by flammability properties. However, their mixture rule for flammables says that if a mixture contains less than 1% of a regulated substance it doesn t need to be considered. If it contains more than 1%, then the entire mixture must be counted as the regulated flammable, unless you can show that the mixture does not meet the definition of an NFPA Flammable Category 4, that is, not having a boiling point below 100 F and flash point below 73 F. As for anhydrous chemicals and chemicals with listed concentrations, the EPA used these approaches much more sparingly. They only listed 3 toxic chemicals as anhydrous and they only listed 4 toxic chemicals with specified concentrations. 17

18 40 CFR Anhydrous chemicals CHEMICAL name CAS* TQ** Ammonia (anhydrous) Hydrogen chloride (anhy.) Sulfur dioxide (anhydrous) *Chemical Abstract Service Number. **Threshold Quantity in pounds 18 Anhydrous ammonia and anhydrous HCl are both also on the PSM list, and with the same threshold quantities. Sulfur dioxide is on the PSM list, but not specifically as an anhydrous compound, and with a threshold quantity of just 1000 pounds. 18

19 40 CFR Listed concentrations CHEMICAL name CAS* TQ** Ammonia solutions (>20%) Hydrochloric acid (>37%) Hydrofluoric acid (>50%) Nitric acid (>80%) *Chemical Abstract Service Number. **Threshold Quantity in pounds 19 Ammonia, hydrochloric acid, hydrofluoric acid, and nitric acid all appear on the PSM lists, but each differs from their listing in the RMP rule, both in terms of listed concentrations and threshold quantities. 19

20 Ammonia CHEMICAL name - OSHA CAS* TQ** Ammonia, Anhydrous Ammonia solutions (> 44%) CHEMICAL name - EPA CAS* TQ** Ammonia (anhydrous) Ammonia (> 20%) *Chemical Abstract Service Number. **Threshold Quantity in pounds 20 Both standards list anhydrous ammonia and ammonia solutions separately. For anhydrous ammonia, both standards have a TQ of 10,000 pounds. It is interesting to note that while anyhydrous ammonia is classified as a Flammable Gas, because its flammable limits are too narrow, both agencies have given it the same TQ that they give flammable gases. When it comes to ammonia solutions, which would typically be in water, the agencies have chosen different concentrations to trigger inclusion and then they have chosen different TQs. An interesting question about the distinction between anhydrous and solutions. Which limit applies if it is an anhydrous solution that is, a solution in something other than water? The standards aren t clear and I haven t been able to find a letter of interpretation that says, one way or the other. On a technical basis, I would expect anhydrous solutions to be treated as anhydrous, simply because the dissociation into ions doesn t happen in other solvents to the extent it does in water. 20

21 Hydrochloric acid CHEMICAL name - OSHA CAS* TQ** Hydrochloric Acid, Anhy Hydrogen Chloride CHEMICAL name - EPA CAS* TQ** Hydrochloric Acid (>37%) Hydrogen Chloride (anhy.) *Chemical Abstract Service Number. **Threshold Quantity in pounds 21 Both standards list hydrochloric acid and hydrogen chloride. In OSHA s case, however, both listings refer to anhydrous hydrogen chloride. Both standards peg the threshold quantity for anhydrous hydrogen chloride at 5000 pounds, whatever its called. The RMP rule considers hydrochloric acid a different material. It has a listed concentration of 37% and as the acid, a much higher threshold quantity. Implicit in the RMP distinction is that hydrochloric acid is a solution in water, where HCl dissociates into ions, which is how I would justify the different TQs. It s not explicitly clear, though. 21

22 Hydrofluoric acid CHEMICAL name - OSHA CAS* TQ** Hydrofluoric Acid, Anhydrous Hydrogen Fluoride CHEMICAL name - EPA CAS* TQ** Hydrogen fluoride / Hydrofluoric acid (> 50%) *Chemical Abstract Service Number. **Threshold Quantity in pounds 22 Both standards list hydrofluoric acid and hydrogen fluoride. In OSHA s case, however, both listings refer to anhydrous hydrogen fluoride, with a threshold quantity of 1000 pounds. The RMP rule mentions both hydrogen fluoride and hydrofluoric acid, but in a single listing and with a listed concentration of 50%, but still with a threshold quantity of 1000 pounds. In the OHSA standard, hydrogen fluoride is not covered if it is a solution in water, and it is not counted if the concentration is less than 1% or the partial pressure of HF is less than 10 mm Hg. In the EPA standard, hydrogen fluoride is covered if it is in a solution of 50% or more, even if the solvent is water. 22

23 Nitric acid CHEMICAL name - OSHA CAS* TQ** Nitric Acid ( > 94.5%) CHEMICAL name - EPA CAS* TQ** Nitric Acid (> 80%) *Chemical Abstract Service Number. **Threshold Quantity in pounds 23 Both standards list nitric acid, but they have picked different concentrations to trigger inclusion, and vastly different threshold quantities. I cannot explain it it s just how it is. 23

24 Definitions - Process 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. 24 The definition of a process is about interconnectedness and co location; it doesn t follow the definition of a process that a process engineer would usually use. It was this quality of interconnectedness that made OSHA want to include atmospheric storage tanks in processes, but that the judge ruled were not part of processes. After determining that a process is covered by the standard, determining the boundaries of the process is the most important step, because it determines how muchand which equipment the standard applies to. 24

25 Appendix C Guidelines for PSM When reduced inventory is not feasible, then the employer might consider dispersing inventory to several locations on site. Dispersing storage into locations where a release in one location will not cause a release in another location is a practical method to also reduce the risk or potential for catastrophic incidents. 25 I think this is the most important thing that OSHA says in the appendices: If you must have more than the TQ on site, you can still avoid having a covered process by dispersing the inventory to different locations around the site. 25

26 What does this mean? As defined by the regulations: A unit or operation is not necessarily a process A facility is not necessarily a process 26 Process engineers frequently use the term unit and process interchangeably. This not what the regulators intend when they use the term. If equipment is interconnected or colocated, it is a single process. On the other hand, the regulators are quite clear that they do not intend for all equipment at a site to be considered automatically as a single process. 26

27 Why does it matter? The PSM Standard has 14 elements For many, compliance is independent of size For some, though, compliance is very dependent on the size of the process:.119(d) Process Safety Information.119(e) Process Hazard Analysis 119(f) Operating Procedures.119(g) Training.119(j) Mechanical Integrity.119(l) Management Of Change 27 The PSM standard has 14 elements for covered processes. For many of those elements, the effort to comply does not increase in proportion to the size of the process. For these elements of PSM, once the question of covered or not covered is settled, there is not much difference in the effort to comply, regardless of the boundaries of the process. However, even OSHA acknowledges that the boundaries of the process will determine which equipment must be evaluated, designed, installed, operated (training and procedures), changed, and inspected/tested/maintained per OSHA PSM requirements. In other words, the extent to which.119(d) process safety information,.119(e) process hazard analysis, 119(f) operating procedures,.119(g) training,.119(j) mechanical integrity, and.119 (l) management of change impose regulatory liabilities on a facility is directly related to the extent of the boundaries. It is perfectly reasonable that a facility can simultaneously seek to be as good at managing process safety as it can be while at the same time want to minimize its regulatory liabilities as much as possible. After all, time spent proving to a regulator that they are safe is time not spent actually being safe, and resources spent addressing fines and citations are resources not available to spend on improving safety. 27

28 Covered processes? Facility I Unit A Unit B Facility II Unit A Unit B Unit C Unit D Unit E 28 Consider Facility I, which has two units that are neither interconnected nor located closely enough that one would effect the other. Unit A contains a highly hazardous chemical, regulated under the standards, but less than the threshold quantity. <click> At the same time, Unit B contains the same highly hazardous chemical, also less than the threshold quantity. <click> Combined, the amount of the regulated chemical exceeds the threshold quantity. Is Facility I a covered process? No. It has two processes, neither of which is covered because neither exceeds the threshold quantity. Now consider Facility II. It has five units. Unit A is connected to Unit B. Unit B is connected to Unit C, which is connected to Unit D, which is connected to Unit E. By the definition of the regulations, this is one process, because they are interconnected. Unit A contains a highly hazardous chemical, regulated under the standards, but less than the threshold quantity. <click> At the same time, Unit B contains the same highly hazardous chemical, also less than the threshold quantity. <click> Combined, the amount of the regulated chemical exceeds the threshold quantity. Is Facility II a covered process? <click> Yes. It has one process and some point in time, the process exceeds the threshold quantity. But what are the boundaries of the covered process? Do they have to include Units C, D, and E? 28

29 OSHA s 3-step analysis Consider the entire collection of interconnected and co-located equipment Determine whether this single comprehensive process at any time contains an amount of an HHC that exceeds the TQ Include any aspect of the single process that contain the HHC or could cause a release or prevent mitigation 29 A memorandum of interpretation (AkzoNobel, 28 Feb 1997) laid out a three step analysis for determining whether a process contained enough material to be a covered process and to determine the limits of that process: 1. Begin by considering all vessels that are interconnected and separate vessels that are co located as a single process. In the example, this includes all five units. 2. Determine whether this single comprehensive process contains at any particular time a quantity of an HHC that exceeds the TQ. In both examples, they are covered processes. 3. Include any aspect of the single process that contains the HHC as part of the covered process. Aspects of the single process that do not contain the HHC, but could cause a release of HHC or interfere with mitigating the consequences of an HHC release are also part of the covered process. Otherwise, aspects that do not contain the HHC are outside the boundary of the covered process. In the second example, Unit C, Unit D, and Unit E would be outside the boundary of the covered process. 29

30 The result of the OSHA 3-step analysis If based on this analysis, it is determined that interconnected equipment downstream from the stipulated covered process cannot cause a HHC release or interfere with the mitigation of the consequences of a HHC release, and the equipment does not itself contain a TQ or greater amount of a HHC, then such equipment could safely be considered outside the limits or boundaries of the covered process. 30 That same 1997 memorandum of interpretation written in response to AkzoNobel included this statement. It means that as long as equipment Doesn t contain highly hazardous materials that contribute to the threshold quantity, Cannot cause the release of a highly hazardous chemical, typically by its failure, Cannot interfere with the mitigation of the consequences of a release, again, typically by its failure, then it does not need to considered part of the covered process. 30

31 cause release or interfere with mitigation Pump seals Inerting systems, utility systems, lube oil systems on large compressors, DCS software, gas detectors (portable and fixed) Relief valves and rupture disks, SIS Fire prevention and protection systems, deluge systems, evacuation alarms 31 In a 2008 letter of interpretation addressed to the API, OSHA gave examples of equipment that did not contain highly hazardous chemicals, but would be considered part of the covered process, either because they could cause a release or because they could interfere with the mitigation of the consequences of a release. 31

32 Utility systems? utility systems are part of the PSMcovered process when employers use them to control/prevent and mitigate catastrophic releases of HHC. 32 OSHA has consistently considered utilities as part of a covered process, but only when the utility is used control, prevent, or mitigate a catastrophic release of highly hazardous chemical. So, a boiler may be part of a covered process, but only if the steam it generates contributes to the control, prevention, or mitigation of a catastrophic release OR if the failure of the steam system leads to a catastrophic release. 32

33 doesn t contribute to the TQ. Flash point less than 100 F Not a Category 1 flammable gas mixture Less concentrated than HHCs with listed concentrations Aqueous solutions of listed anhydrous HHCs In mixtures at less than 1% In mixtures with a partial pressure of the HHC less than 10 mm Hg 33 33

34 Defining the boundaries an approach Begin with a process that contains a highly hazardous chemical include all interconnected and collocated equipment. Remember that the regulations define processes in terms of equipment, not units or operations. On a set of P&IDs that capture the entire process, identify all equipment in terms of five groups, beginning with Group 1 and finishing with Group

35 Five groups Group 1: Any equipment or piping that contains HHCs that contribute to the TQ Group 2: Equipment that doesn t contain HHCs, but could be exposed to HHCs upon a single failure or error, e.g. a valve opens or a heat exchanger tube fails. Group 3: Equipment with contents that could become HHCs upon a single failure or error, e.g. concentration exceeds 1% or temp increases, increasing partial pressure 35 35

36 Five groups Group 4: Equipment, the failure of which could cause a catastrophic release or disable mitigation against a catastrophic release Group 5: Anything that does not fall into Groups 1, 2, 3, or 4 Groups 1, 2, 3, and 4 are within the covered process; Group 5 is not

37 The difference between stupidity and genius is that genius has its limits. Albert Einstein 37 We have generally found that deciding whether or not a process is covered by the PSM standard is not usually controversial. Does the process contain, in aggregate, more than 10,000 lbs of liquids with a flash point below 100 F? This is the most common reason we have encountered for a process to be covered by the PSM standard. Does it contain, in aggregate, more than 10,000 lbs of Category 1 flammable gases? Does it contain, by chemical, more than the specific threshold quantity of one of the toxic or reactive chemicals listed in the regulations? If there are questions, they are often about the exceptions hydrocarbon fuels used solely for workplace consumption as fuels, and storage of flammable liquids in atmospheric tanks or the exemptions retail facilities, NURFs, or why farmers get a pass on ammonia. More often, though, questions are about what constitutes a process, and the boundaries of a process. Covered processes can have boundaries, but it is up to you to establish what they are. 37