OSHA PSM standard

The information in this publication is applicable to many industrial facilities not covered by process safety regulations such as the OSHA PSM Standard and the Seveso II Directive. Many reactive chemicals are not listed as regulated materials, and chemical reactivity hazards include uncontrolled chemical reactions between materials not considered as highly hazardous, or under conditions not typically encountered in storage and shipping. 

CCPS Elements OSHA PSM Standard and EPA RMP Rule Seveso II... 

For the purpose of the OSHA PSM Standard, NFPA instability ratings have the following limitations with respect to identifying reactive hazards ... 

The OSHA PSM Standard lists 137 highly hazardous chemi-cals-only 38 of which are considered highly reactive based on NFPA instability ratings of "3" or "4."... 

OSHA PSM Standard (29 CFR 1910.119) and EPA Accidental Release Prevention Requirements Risk Management Programs (RMP) Under the Clean Air Act, Section 112(r)(7) (40 CFR 68). 

The OSHA PSM Standard has significant gaps in coverage of reactive hazards because it is based on a limited list of individual chemicals with inherently reactive properties. 

NFPA instability ratings are insufficient as the sole basis for determining coverage of reactive hazards in the OSHA PSM Standard. 

The OSHA PSM Standard and the EPA RMP regulation do not explicitly require the use of multiple sources when compiling process safety information. 

Neither the OSHA PSM Standard nor the EPA RMP regulation explicitly requires specific hazards, such as reactive hazards, to be examined when performing a process hazard analysis. 

For processes already covered under the OSHA PSM Standard, do the safety management requirements of the standard adequately address reactive hazards If not, what should be added or changed ... 

The CSB incident data were analyzed to determine whether the chemicals involved were considered highly hazardous under the OSHA PSM Standard. For the purposes of analyzing the data, CSB determined if a chemical was covered by OSHA PSM by identifying whether it was listed in PSM or was covered as a flammable chemical by OSHA definition.38... 

Processes that are covered by the OSHA PSM Standard due to the presence of flammable substances may, in fact, have significant reactive hazards as well. An example is a polymerization reaction involving the flammable chemical 1,3-butadiene. Such processes are required to address all chemical hazards, including reactive hazards. 

The OSHA PSM Standard lists 131 distinct chemicals with toxic or reactive properties.40 It includes 25 chemicals with an NFPA rating of 3 and 13 chemicals with an NFPA rating of 4. PSM applies to processes that involve listed chemicals at or above threshold quantities and to processes with flammable liquids or gases onsite in one location, in quantities of 10,000 pounds or more. Companies that manufacture explosives and pyrotechnics are also required to comply with the standard. 

RMP requires covered processes to have a hazard assessment, a prevention program, and an emergency response program. The hazard assessment must evaluate the accidental release of regulated substances, including the worst case scenario. RMP contains requirements for prevention of accidental releases, which include the same basic elements as the OSHA PSM Standard. Therefore, the limitations described in Section 5.1.2.2 with respect to process safety information and process hazard analysis also apply to RMP. 

There are significant differences in the laws authorizing the OSHA PSM Standard and the EPA RMP regulation. Because EPA specifically lists substances covered under RMP and does not establish classes of substances, this report separately discusses alternatives for OSHA (Section 8.1) and EPA (Section 8.2). (Section 8.3 briefly discusses regulatory relief absent catastrophic consequences, and Section 8.4 suggests improvements within the requirements of the existing PSM Standard and RMP regulation to enhance hazard identification and hazard evaluation.)... 

To most effectively improve reactive hazard management, coverage under the OSHA PSM Standard and the EPA RMP regulation should be more compatible. EPA should seek the authority needed to allow it to address reactive hazard coverage in a manner compatible with any revised OSHA approach. 

The PSI element of both the OSHA PSM Standard and the EPA RMP regulation can be improved by requiring the inclusion of all existing information on chemical reactivity. Examples of such information are chemical reactivity test data, such as DSC, thermogravimetric analysis (TGA), or accelerating rate calorimetry and relevant incident reports from the plant, the corporation, industry, and government. OSHA and EPA should require the facility to consult such resources as Bretherick s Handbook of Reactive Chemical Hazards,Sax s Dangerous Properties of Industrial Materials, and computerized tools (e g., CHETAH, The Chemical Reactivity Work Sheet). 

In both the OSHA PSM Standard and the EPA RMP regulation, the PHA element does not currently specify the factors that must be considered to effectively manage reactive hazards. Present requirements should be augmented to explicitly require an evaluation of such factors as rate and quantity of heat generated maximum operating temperature to avoid decomposition thermostability of reactants, reaction mixtures, byproduct waste streams, and products effect of charging rates, catalyst addition, and possible contaminants and understanding the consequences of runaway reactions or toxic gas evolution. 

Program Level 3 Conduct a hazard assessment, document a management system, implement a prevention program that is basically identical to the OSHA PSM Standard, and implement an emergency response program. 

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