Chemical reactivity hazard regulation

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. 

Using lists of chemicals is an inadequate approach for regulatory coverage of reactive hazards. Improving reactive hazard management requires that both regulators and industry address the hazards from combinations of chemicals and process-specific conditions rather than focus exclusively on the inherent properties of individual chemicals. (CSB 2002b)1... 

As a result of the joint OSHA-EPA chemical accident investigation of the Napp Technologies incident in April 1995, a recommendation was made by EPA and OSHA to consider adding more reactive chemicals to their respective lists of chemicals covered by process safety regulations. To date, neither OSHA nor EPA process safety regulations have been modified to better cover reactive hazards. 

Revise the Accidental Release Prevention Requirements, 40 CFR 68 (RMP), to explicitly cover catastrophic reactive hazards that have the potential to seriously impact the public, including those resulting from self-reactive chemicals and combinations of chemicals and process-specific conditions. Take into account the recommendations of this report to OSHA on reactive hazard coverage. Seek congressional authority if necessary to amend the regulation. 

Hazards arising from reactive chemicals are covered by a variety of legal requirements and regulations, including regulations of OSHA and EPA. CSB examined these authorities and regulations to determine how reactive hazards are currently addressed. 

What criteria could be used in the context of process safety regulations to classify chemical mixtures as highly hazardous due to chemical reactivity ... 

Among governmental regulations, voluntary guidelines, or trade association codes of practice, there is no standard approach to classifying hazardous chemical reactivity. A variety of methods are used to address self-reactivity (e.g., decomposition reactions and some polymerization reactions) and chemical incompatibility. 

CSB found significant gaps in OSHA process safety regulations designed to protect workers from highly hazardous chemicals, including reactive hazards. OSHA standards cover the hazards of some classes of substances, such as flammable and combustible liquids however, no OSHA standard specifically addresses reactive hazards. 

Numerous other OSHA regulations apply to the chemical industry in general, but are not specific to reactive hazards. Where no specific OSHA standards apply, the OSHA General Duty Clause (GDC Section 5(a)(1) of the 1970 Occupational Safety and Health Act) creates a legal obligation for an employer to address a known hazard, including a reactive hazard. 

The concept of a safety case comes from the requirements of the European Union/European Community (EU/EC) Seveso Directive (82/501/EC) and, in particular, regulations that the United Kingdom and other member states used to implement that directive. United Kingdom regulations (Control of Industrial Major Accident Hazards [CIMAH], 1984 replaced by Control of Major Accident Hazards Involving Dangerous Substances [COMAH] in 1999) require that major hazardous facilities produce a safety report or safety case.64 The requirement for a safety case is initiated by a list of chemicals and a class of flammables. Like the hazard analysis approach (Section 8.1.2), experts identify the reactive hazards of the process if analysis shows that the proposed process is safe, it may be excluded from additional regulatory requirements. 

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). 

A reactive chemicals/process hazard analysis (PHA) to be completed every three years (see Reference 11). Special consideration may be given to facilities that have lower levels of process risk and which have demonstrated superior safety performance to extend this frequency up to five years. Facilities that pose higher process risk or who have lower safety performance may be recommended to have reactive chemicals/PHA reviews more frequent than every three years. In certain countries, government regulation will determine the frequency and other requirements for Process Hazard Analysis reviews. Dow will follow the government requirements where they are more stringent. 

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