Elements of process safetymanagement: Part 1

By Eileen Mason

Because of the inherent poten-tial for catastrophic losses as-sociated with large-scale

chemical processes, the chemical in-dustry has zealously pursued opera-tional safety. Although the industry asa whole has demonstrated the value ofa systems safety approach, few chem-ists are aware of the provisions of theOccupational Safety and Health Ad-ministration (OSHA) standard thatapplies this technique to the specificrisks of bulk processes that use haz-ardous chemicals. This article and onethat will appear in the next issue de-scribe the development of the processsafety management (PSM) regulationand discuss the requirements of eachelement of that standard.

29 CFR 1910.119, Process SafetyManagement of Highly HazardousChemicals,1 applies the principles ofsystems safety to chemical processes.It is the only OSHA standard thatmandates a systems safety approach tocontrolling hazards. It also stands incontrast to other OSHA standardsthat have been bitterly opposed by in-dustry. Driven by public demand,both government and industry initi-ated programs to address the problemof catastrophic chemical releases,fires, and explosions, and this finalstandard was developed with inputfrom both industry and labor.

ORIGINS OF THE STANDARD

During the 1970s and 1980s, the anti-technology attitudes and environmen-tal advocacy of the 1960s were rein-forced by public reaction to chemicalreleases of national and even interna-tional significance. The final report ofthe EPA’s Acute Hazardous EventsDatabase, issued in 1989, documentsmore than 11,000 events in a period ofeight years. In response, the petro-chemical industry initiated programsto increase chemical safety. The Amer-ican Petroleum Institute issuedRP750, “Management of Process Haz-ards,” and the Chemical Manufactur-ers’ Association launched the Respon-sible Care directives. Governmentresponse included Section 304 of the1990 Clean Air Act Amendments,which also addressed catastrophic re-leases and required the Secretary ofLabor to promulgate a chemical pro-cess safety standard in coordinationwith the administrator of the EPA.

Development of the final PSM stan-dard was characterized by strong sup-portive commentary. BP Oil Company(Tr. 1802, as quoted in Preamble toProcess Safety Management of HighlyHazardous Chemicals2) regarded theproposed regulation as “of major im-portance.” The American PetroleumInstitute commented that “API mem-ber companies support OSHA’s effortto develop an effective PSM rule. APIbelieves PSM is the most effective ap-proach available in the prevention ofcatastrophic releases” (Preamble, Ex.3:106). The representative from OryxEnergy Company testified, “I know ofno other system that is better than thesystem that is proposed by OSHA.”The proposed standard also receivedstrong support from labor unions. TheFood and Allied Service Trades of the

AFL-CIO (Preamble, Ex. 3:25, p. 2),remarked, “The proposed rule is well-intended and there is little questionthat such regulation is needed. Recentevents…underscore this need.” As theUnited Steelworkers of America ob-served (Preamble, p. 2, Tr. 2231),“Had such a standard been in place atNeville Chemical, Jim Thompsonwould be alive today. So might all theother chemical workers killed by acci-dental releases of hazardous chemi-cals in the past several years…Clearly,it is time to give OSHA inspectors thetools they need to prevent cata-strophic accidents. It is also time togive workers the tools they need toprotect themselves and theircommunities.”

The final standard is only 21 pageslong. One of these pages is devoted todefinitions, and 14 pages compriseappendices. For comparison, theHazardous Waste Operations andEmergency Response (HAZWOPER)standard is 40 pages long, 23 pagescomprising the standard itself and 17pages comprising appendices. Thebrevity of 29 CFR 1910.119, however,belies the complexity of implementinga performance standard for systemssafety. Documentation of the requiredelements of PSM for a single processcan easily fill entire file cabinets.

In a “prescriptive” standard, OSHAdetails exactly what actions the em-ployer must take to comply. For exam-ple, the HAZWOPER standard re-quires a certain number of hours ofinitial training for each level and acertain number of hours of annual re-fresher training. Under newer “perfor-mance” standards, OSHA states theobjectives but allows the employer todetermine exactly how those objec-tives are to be achieved. The Hazard

Eileen Mason, Ph.D., CIH, CSP, isaffiliated with the EnvironmentalHealth Department of OldDominion University, Room 212D,William Spong Hall, Norfolk, VA23529-0286 (e-mail:emason@odu.edu).

FEATURE

22 © Division of Chemical Health and Safety of the American Chemical Society 1074-9098/01/$20.00Published by Elsevier Science Inc. PII S1074-9098(01)00214-3

Communication standard specifiesthe general content of required train-ing, but unlike HAZWOPER, it doesnot mandate the number of hours tobe spent on training. Refresher train-ing is required when new hazards areintroduced into the workplace ratherthan on an annual basis.

Despite industry support during therule-making process, most chemistsare unaware of the requirements of 29CFR 1910.119. Those who are awareof the regulation may not be techni-cally prepared to address PSM issues.This skill is rarely included in aca-demic curricula for chemists or forchemical engineers. Chemical engi-neers are more likely than chemists tounderstand the procedures and thehardware involved in the process, butapplication of the suggested hazardanalysis techniques takes specializedtraining that is usually reserved forsafety engineers.

PURPOSE AND SCOPE OF 29 CFR1910.119The purpose of the PSM standard is toprevent or minimize the consequencesof catastrophic releases of toxic, reac-tive, flammable, or explosive chemi-cals. Such releases may result in fire,explosion, or hazardous exposures totoxins.

Application of the standard is notbased on the standard industrial code(SIC) of the facility to be regulated. Itis based solely on the presence offlammable liquids or any of the 137highly hazardous chemicals listed inAppendix A of 29 CFR 1910.119. Be-cause the standard addresses “cata-strophic” releases, it applies onlywhen one of the flammable or highlyhazardous chemicals is present at orabove specified threshold quantities.Threshold quantities vary from 100 lbfor the most highly hazardous sub-stances, such as phosgene, to 15,000lb for concentrated (.44%) solutionsof ammonia.

Appendix A of 29 CFR 1910.119 in-cludes chemicals that are toxic, reac-tive, flammable, or explosive; it wasdeveloped from a variety of sources,including individual state, national,and international lists, such as EPA’s“Extremely Hazardous Substance

List,” the World Bank’s “Manual ofIndustrial Hazard Assessment Tech-niques,” and the European Communi-ty’s Seveso Directive (82/501/EEC).Substances listed with the AmericanPetroleum Institute’s RP750, “Man-agement of Process Hazards,” and theNational Fire Protection Association’sNFPA 49 were also included (Pream-ble, p. 9).

The threshold amount of regulatedhighly hazardous chemical must beused in a single process and be presentat one time. Amounts present at sep-arate locations or at different times arenot considered to present the samedegree of hazard. Many municipalitiesthat did not consider themselves to be“industrial” were shocked to discoverthat the use of compressed chlorinegas for water purification made treat-ment plants subject to PSM. Anhy-drous ammonia refrigeration units arealso subject to regulations if morethan 10,000 lb of the material arepresent.

Exemptions from PSM apply to cer-tain types of facilities, such as retailfacilities, where hazardous chemicalswould normally be present in smallcontainers; oil or gas well drilling orservicing operations; or normally un-occupied remote facilities. An exempt“remote” facility must be noncontigu-ous with and remote from all otherbuildings, processes, or people. Noemployees may be permanently sta-tioned there, although employees mayperiodically be present to check oper-ations or perform necessary operatingor maintenance tasks.

Although threshold quantities offlammable liquids are regulated, hy-drocarbon fuels used solely for work-place consumption and flammable liq-uids stored below normal boilingtemperature in unrefrigerated atmo-spheric tanks are permitted.

REQUIREMENTS OF THE STANDARDAs processes become ever more com-plex and the number of conditions tobe controlled becomes overwhelming,a structured approach is needed to en-sure safe operation. Implementationof the PSM standard is based on 14interrelated core elements that definethe process system:

1. Employee participation.2. Process safety information.3. Process hazard analysis.4. Operating procedures.5. Training requirements.6. Contractors.7. Prestartup safety review.8. Mechanical integrity.9. Hot work permits.

10. Management of change.11. Incident investigation.12. Emergency planning and response.13. Compliance audits.14. Availability of trade secret

information.

Each of these elements addresses anessential part of the process system, sothat safety becomes an integral part ofthe process itself.

EMPLOYEE PARTICIPATIONOSHA has repeatedly stressed the im-portance of employee participation inall safety activities, and employee con-sultation in PSM was specifically re-quired by section 304(c)(3) of theClean Air Act Amendments. UnderPSM, not only do employees have aright to know the information devel-oped about process hazards, the em-ployees must also be consulted aboutthe general development of the pro-gram and actively involved in certainelements.

Employees who are members of aprocess hazard analysis (PHA) teamshould be chosen on the basis of theirknowledge of the unit under investi-gation and the operating and mainte-nance practices for that unit, ratherthan on the basis of seniority or orga-nizational (e.g., union) affiliation.

Further, employers must develop awritten plan of action detailing exactlyhow employee participation will beimplemented.

PROCESS SAFETY INFORMATIONCompilation of process safety infor-mation establishes the basis for iden-tification and understanding of thehazards involved in the process. Thisbasis is absolutely necessary for thedevelopment of a PHA. For this rea-son, written process safety informa-tion must be compiled before any pro-

23Chemical Health & Safety, July/August 2001

cess hazard review can be conducted,although it may be assembled on aprocess-by-process basis. It is not nec-essary to compile all process safety in-formation before any process hazardsreview may be performed.

Much of the required informationfor the hazardous chemicals them-selves can be obtained from the Man-ufacturer’s Safety Data Sheet (MSDS).However, an MSDS is not likely toinclude specific corrosivity data or in-formation on the hazardous effects ofinadvertent but reasonably foresee-able mixing of different materials. Thisis an area in which chemists areuniquely qualified to provide informa-tion for the PSM process. In fact, aninformed chemist can begin accumu-lating this data at the R&D stage, be-fore scale-up occurs. Effects of inad-vertent mixing are often documentedby means of a matrix that shows thelikely reaction products of all pairs ofchemicals added to the process.

The chemical information should beintegrated with process technology in-formation, including a block flow dia-gram of the process, a summary of theprocess chemistry, and maximum in-tended inventory. Safe upper andlower limits of process operating pa-rameters, such as temperature, pres-sure, flow rates, and composition,should be documented. The conse-quences of deviation from these limitsshould be evaluated. This is just an-other example of the relationship be-tween safe operation and quality con-trol initiatives. In many processes,proper parameter control for qualityproduction is more stringent than thecontrol needed to prevent a safety in-cident. Under these conditions, oper-ation within limits required by qualitycontrol will guarantee a safe process.

Process technology informationalso includes pertinent informationabout the equipment used. This topicis best addressed by the process engi-neer. The facilities engineer and main-tenance personnel may also be valu-able resources in developing thisinformation.

Information pertaining to equip-ment must include identification of

materials of construction, piping andinstrument diagrams, electrical classi-fication, relief and ventilation systemdesigns, and verification that equip-ment conforms to appropriate designcodes and standards.

PHANo single person will have all theknowledge and experience necessaryto perform an effective PHA. Becauseof the breadth of knowledge requiredto perform a PHA, OSHA has man-dated that PHAs be carried out by ateam with expertise in engineeringand process operations. The teammust include at least one employeefamiliar with day-to-day operationsand one member knowledgeable inthe specific PHA method to be used.

Development of “what if?” scenar-ios and the use of checklists can serveas a platform for PHA. Hazard andoperability study (HAZOP) proce-dures, failure mode and effects analy-sis, and fault tree analysis are also rec-ommended techniques. Otherequivalent methods or a combinationof methods may be used if appropriatefor the complexity of the particularprocess.

Although expertise in methods ofsystem safety analysis is common inthe aerospace and nuclear industries,it is much less frequently encounteredin the chemical industry. The first stepin PHA may be to train the team mem-bers in the analysis techniques to beused. Because HAZOP was developedwithin the chemical industry specifi-cally to improve operating character-istics of new processes, it is frequentlythe method of choice. Appendix D of29 CFR 1910.119 includes referencesto help employers develop and con-duct PHAs.

In addition to the direct hazards ofthe process, the PHA should alsoidentify and address previous inci-dents that are likely to present cata-strophic consequences, the engineer-ing and administrative controls toensure the safety of the process, andthe consequences should these con-trols fail. A qualitative evaluation

must be made of the safety and healtheffects on employees in the event ofthe failure of the controls. This evalu-ation is the basis for planning preven-tion, control, mitigation, and emer-gency response to any release. Humanfactors and the consequences of facil-ity siting must also be included in theanalysis.

OSHA requires that all safety issuesand recommendations resulting froma PHA be resolved. If further researchindicates that a recommendation isunnecessary or that other technologyexists to address the situation, thatrecommendation may be resolvedwithout implementation of the correc-tion suggested by the PHA team.

PHAs must be reviewed, updated,and revalidated by the team at leastevery five years. Changes occurring inthe process during this period must beaddressed under the management ofchange requirements of the standard.The initial and updated reviews andthe documented resolution of recom-mendations proceeding from the anal-ysis must be retained. This informa-tion must be communicated to allemployees who are potentially ex-posed to the hazards of the process,including contractors.

Together, the process safety infor-mation database and the PHA formthe foundation for other elements ofthe standard: operating procedures,training requirements, prestartup re-views, mechanical integrity, manage-ment of change, and emergency plan-ning and response. Contractorrequirements and incident investiga-tions are important elements of a com-prehensive safety program but are notlegal requirements under any otherstandard. The remaining elements ofPSM will be discussed in a futurearticle.

References1. OSHA Preambles: Process safety man-

agement (29 CFR 1910.119), III.Summary and explanation of thefinal rule: www.osha-slc.gov/Preamble/PSManage_data/PROCESS3.html, 1992.

2. 29 CFR 1910.119: Process safety man-agement of highly hazardous chemi-cals.

24 Chemical Health & Safety, July/August 2001