Overview of Requirments for Process Hazard Analysis Under the PSM Rule

DOE-HDBK-1100-2004

2.0

OVERVIEW OF REQUIREMENTS FOR PROCESS HAZARD ANALYSIS

UNDER THE PSM RULE

Under the PSM Rule, the PrHA element requires the selection and application of appropriate

hazard analysis methods to systematically identify hazards and potential accident scenarios

associated with highly hazardous chemicals. The components of a PrHA are summarized and

explained below.

2.1

Process Safety Information

The PSM Rule requires that up-to-date process safety information exist before conducting a

PrHA, with the exception of technology information that can be created in conjunction with the

PrHA. Complete and accurate written information about process chemicals, technology, and

equipment is essential to the team that performs a PrHA. It is also needed by personnel

developing training programs and operating procedures, subcontractors whose employees work

with the process, teams conducting pre-startup reviews, and local emergency preparedness

planners.

2.1.1 Information About Highly Hazardous Process Chemicals

Information about the chemicals used in a process, as well as chemical intermediates, must be

comprehensive enough for an accurate assessment of fire and explosion characteristics,

reactivity hazards, safety and health hazards to workers, and corrosion and erosion effects on

process equipment and monitoring tools. Information must include, at a minimum: (1) toxicity

information; (2) permissible exposure limits; (3) physical data such as boiling point, freezing

point, liquid/vapor densities, vapor pressure, flash point, autoignition temperature, flammability

limits (LFL and UFL), solubility, appearance, and odor; (4) reactivity data, including potential

for ignition or explosion; (5) corrosivity data, including effects on metals, building materials,

and organic tissues; (6) identified incompatibilities and dangerous contaminants; and (7) thermal

data (heat of reaction, heat of combustion). Current Material Safety Data Sheets (MSDSs) may

be used to help meet this requirement. Where applicable, process chemistry information should

be included about potential runaway reactions and overpressure hazards and hazards arising

from the inadvertent mixing of incompatible chemicals.

2.1.2 Information About Process Technology

Process technology information must include at least: (1) block flow diagrams or simplified

process flow diagrams such as the type shown in Figure 4.1; (2) process chemistry; (3) DOE

contractor-established criteria for maximum inventory levels for process chemicals; (4) process

limits that, when exceeded, are considered an upset condition; and (5) qualitative estimates of

the consequences of deviations that could occur if established process limits are exceeded. If the

original technology information is not available, it can be created in conjunction with the PrHA.