Office of Solid Waste EPA 550-F-04-005
and Emergency Response February 2005
MANAGING CHEMICAL REACTIVITY HAZARDS
The Environmental Protection Agency (EPA) is issuing this Alert as part of its ongoing effort
to protect human health and the environment. EPA is striving to learn the causes and
contributing factors associated with chemical accidents and to prevent their recurrence. Major
chemical accidents cannot be prevented solely through regulatory requirements, but by
understanding the fundamental root causes, widely disseminating the lessons learned, and
integrating these lessons learned into safe operations. EPA publishes Alerts to increase
awareness of possible hazards. It is important that facilities, SERCs, LEPCs, emergency
responders and others review this information and take appropriate steps to minimize risk.
PROBLEM chemical reactivity hazards, this alert
focuses on the management of the
any materials used in hazards. This alert does not cover all
M industrial facilities can pose
chemical reactivity hazards.
Conventional management systems
ten essential management practices,
but highlights some common
frequently do not adequately address
the unique behavior of materials that This alert assumes that the reader has
may react to cause excessive determined that a chemical reactivity
temperature or pressure excursions or hazard exists at the facility and has:
toxic or corrosive emissions.
• Explored opportunities, such as
Incidents occur not only at chemical substituting inherently safer
manufacturing and processing plants, chemicals, to reduce or eliminate
but also at water treatment plants, reactivity hazards;
swimming pools and spas, metal • Gathered available information
processing facilities, and mechanical from available sources such as
equipment manufacturing facilities. MSDS.
• Completed preliminary screening
to identify chemical reactivity
PURPOSE hazards (see the EPA companion
alert Identifying Chemical
he purpose of this alert is to
T introduce facilities to the
methodology for chemical
Reactivity Hazards: Preliminary
Screening Method for additional
reactivity hazard management as • Developed a matrix indicating
developed by the Center for Chemical which chemicals react with each
Process Safety (CCPS) and made other, including the process or
available in a book Essential operating area where the chemicals
Practices for Managing Chemical are located;
Reactivity Hazards. This alert is a • Gained management commitment
follow-on to the recent EPA alert to the safe operation of the facility;
which discusses the CCPS method for • Ensured resources are available to
screening facilities for chemical ensure physical plant is designed
reactivity hazards. While the first or modified as necessary to
EPA alert focused on identifying mitigate chemical reactivity hazard
Office of Emergency Management
exposure; likelihood of a serious process safety incident.
• Implemented a sound training program,
operating procedures, and hazard March, 1997 - The facility provides an antimony
communication program; and catalyst service. A 1000-pound horizontal
• Implemented an active safety audit program. cylindrical container was in the process of having a
small sample drawn into an open container.
INCIDENT EXAMPLES However, the handle of the quarter-turn valve
leading to the dip-leg had been removed by the
number of incidents involving reactive customer before returning the container of spent
A chemicals have resulted in accidental
chemical releases, fire, and explosions.
The following section describes several recent
catalyst. The employee opened the valve using a
vice-grip tool but was then unable to close the
valve. Escaping spent antimony catalyst was
believed to have reacted with moisture in the
atmosphere, to create hydrogen chloride. The
September, 2004 - A transport vessel containing a incident investigation led to a management-of-
mixture of recovered monomer was observed to be change review, revised sampling procedures and
relieving pressure via the pressure relief valve. The training and a closed sampling system that
relief valve was lifting (relieving) as a result of the discharges to a scrubber system. This incident
pressure in the vessel exceeding the relief valve illustrates the need for particular attention to
setting. The increased pressure was caused by an operations that involve removing material from the
increase in the temperature within the container. enclosed system, such as when venting, draining or
This temperature increase was caused by a sampling.
polymerization reaction of the monomer mixture.
A water deluge was applied to cool the transport July, 1994 - New steel saddles (internal saddle
vessel and minimize the vapor cloud dispersion. shaped devices used to promote mixing) were
The accident investigation revealed a blockage in installed in the direct-contact chiller vessel ahead
the injection feed line which obstructed the of the chlorine compressor. The saddles should
addition of inhibitor into the monomer mixture. have had no corrosion protection coating, but they
The immediate term procedure modifications were did have an undetected coating of mineral oil.
to manually control the inhibitor injection and, When the main stream of chlorine and the chilling
also, to verify inhibitor concentration after loading material, which was also chlorine, entered the
the transport vessel. The longer term modification chiller vessel, there was an intense exothermic
includes automatic inhibitor addition with post reaction between the chlorine and the mineral oil
loading verification of inhibitor concentration. which burned through the vessel wall, releasing
chlorine to the atmosphere. The subsequent
March, 2004 - Operations personnel were incident investigation, the management-of-change
preparing to unload a railcar of methyl chloride review, and the operating procedure revision
when they discovered a product identification label focused on verification that mechanical equipment
attached to the railcar dome reading “methylene that may come into contact with chlorine is
chloride.” Because the label and placards were not confirmed to be free of any material with which
in agreement, personnel quarantined the railcar chlorine may react. This incident highlights the
until proper chemical verification could be made need to consider not only process chemicals, but
with the supplier and the facility quality control other chemicals and contaminants as well.
laboratory. The verification confirmed that the
railcar placarding for methyl chloride was correct.
Close attention to material identification used
triggered personnel to take steps to verify the
contends of the railcar, thereby reducing the
Office of Emergency Management
MANAGEMENT OF REACTIVE systems include:
HAZARDS Communicate and Train on Chemical
he consequences of a reactive chemical
T incident can be severe. In a 2002 study, the
U.S. Chemical Safety Board (CSB) collected
detailed information on 167 serious incidents that
Training activities and materials should
incorporate the hazards of chemical reactivity and
provide information relevant to workers directing
occurred between 1980 and 2001. EPA reviewed and performing process operations. The following
CSB’s information and identified the most are some suggestions for improving
commonly reported management deficiencies. In communication and training about reactive hazards
order of frequency, the reported management within a facility:
• State not only the steps required to correctly
• Operating Procedures, Safe Operating Limits execute the operation, but also the
and Training consequences of deviation. Develop likely
• Hazard Identification and Evaluation scenarios such as incorrect charging,
• Human Factors contamination of the process, or operating the
• Management of Change process in the wrong range.
• Emergency Relief Equipment and Controls • Integrate information about chemical reactivity
• Process Design hazards into the operating procedures and
• Process Knowledge instructions, rather than separately appending it
• Incident Investigation to the instructions.
• Process Hazard Analysis • Clearly state safe operating limits and the
• Safety Auditing actions to be taken if operating deviations
• Equipment Maintenance occur.
• Because concepts concerning reactivity hazards
In their Reactive Hazard Investigation report, CSB may be unfamiliar to some operating staff, these
points to the limited availability of accurate concepts should be clearly and simply worded.
reactive chemical incident data. In spite of these • Chemical reactivity hazards information should
limitations, we believe that this data set is useful in be included in the facility’s material safety data
identifying areas of management systems that need sheet (MSDS) and, if necessary, described in
to be strengthened in order to address the hazards detail in instructions accompanying the MSDS.
of reactive chemicals. • Share training materials with all operating
personnel, including contractors.
To assist facilities in managing these risks, the • Facility management should ensure that training
Center for Chemical Process Safety (CCPS) is understood by employees and contractors.
sponsored the concept book Essential Practices for
Managing Chemical Reactivity Hazards and with Identify Process Controls and Risk
the support of its government and industry partners Management Options
has made this book available free of charge from
the Internet. Chapter 4 of this book discusses ten The materials receiving and transfer system should
essential practices for managing chemical be designed to guard against inadvertent mixing or
reactivity hazards. This alert does not cover all ten incorrect handling.
management practices but highlights some
common management deficiencies. • Material receipt - Is a procedure in place,
possibly sampling, to check the material
Recommendations for strengthening management received to ensure that it is the correct material?
Office of Emergency Management
• Connection points- Is the connection clearly safety, health and environmental protection should
marked and/or color coded to guard against be freely exchanged between organizations within
delivering to the wrong point? Incompatible industry and by technical societies.
couplings may also have an application.
• Have piping manifolds, including sampling • Does the facility management have at least one
lines, blow-down and venting or flaring systems person designated to explore available
been checked to guard against cross connections information on chemical reactivity hazards that
that can lead to inadvertent mixing? may pertain to their operations?
• If incompatible materials are not handled in • Is information gathered from the above sources
dedicated systems, are there positive isolation distilled down into an understandable form and
methods (spectacle blinds, drop-out, double made available to persons that may be involved
block and bleed valve stations) used to prevent with or exposed to the hazards of reactive
inadvertent mixing? chemicals present at the operating facility?
• Positive Materials Identification (PMI) - Has • Is every opportunity taken to upgrade operating
the material handling equipment been checked procedures and instructions as new information
to ensure that it is suitable for the material to becomes known?
which it is exposed? In addition to the piping, • Is facility management strongly encouraged to
vessels, pumps and valving, the internal trim, contribute its own new information, including
packing, and lubrication and sealant must be lessons learned and near-misses to others within
Appropriate safeguards should be considered to Conduct a Process Hazard Analysis (PHA)
minimize hazards related to storage of reactive
materials. Many methods of conducting a PHA are suitable
for assessing the hazards associated with operation
• Can the material deteriorate and become of facilities involving reactive materials or
unstable because of the ambient temperature mixtures. Several methods, such as “hazard and
being too high, or too low, or because of operability” and “what-if,” rely on a base set of
excessive shelf time? questions for identifying risks. These base sets of
• If containment is breached, will materials questions should be expanded to include aspects
become exposed to air or water to which they that may be unique to reactive chemicals.
are reactive? Additionally, any process change that is made
• Are incompatible materials stored the proper should receive a management of change (MOC)
distance apart, or otherwise isolated? review.
• Can breached containers allow incompatible
chemicals to mix and react? Consider Abnormal Situations
• Has equipment used in the storage area been
evaluated to ensure that it will not act as a heat The severity of many chemical accidents can be
or ignition source or cause instability (example attributed to a reluctance to seriously consider all
- fork-lift truck exhaust in a dusty
scenarios and to develop an appropriate action
plans. Identifying and evaluating deviations that
• Are sensors and alarms located in the storage to may occur and developing appropriate responses
alert personnel in the event of a release or slow must be thought out before the fact. Possible
leak? abnormal situations must be documented and
incorporated into instructions and training for
Manage Process Knowledge operating personnel and for emergency responders.
Otherwise, there is likely to be no response or an
Technical information pertaining to fire protection, inadequate one. Some questions that should be
Office of Emergency Management
considered: RECOMMENDED READING
• What out-of-control conditions are possible? Essential Practices for Managing Chemical
What remedial steps are authorized and by Reactivity Hazards – 2003, 194 pages, – Chemical
whom? Center for Process Safety (CCPS).
• What firefighting actions may be taken?
What actions should be avoided? CCPS has teamed with US OSHA, US EPA, the
• Is emergency response equipment American Chemistry Council, the Synthetic
appropriately located and accessible in all Chemical Manufacturers Association, and Knovel
types of situations? corporation to make this important new CCPS
• Which neutralizing or mitigation initiatives concept book available for free on the Internet.
may be taken? “Essential Practices” identifies a simple process to
• What secondary hazards may result from determine if your operation may be at risk of a
pressure relief or blow-down systems? chemical reactivity incident, and then guides you
• What contaminants are likely to be
to resources to manage that risk. Persons wishing
free online access to this book will need to follow
a one-time sign-up procedure through Knovel,
Conduct Frequent Audits CCPS's on-line book distributor, prior to gaining
access to the document.
Safety, health and environmental (SHE) audits can http://info.knovel.com/ccps/
serve a number of invaluable functions, including
verification that the concepts of reactive chemical Chemical Safety Alert: Identifying Chemical
hazards are understood by operating personnel and Reactivity Hazards Preliminary Screening
have been built into the operation. The SHE audit Method – 2004, 5 pages -- US EPA.
may be the last line of defense against an accident.
In verifying that the management system is The purpose of this alert is to introduce small- and
reliable, the SHE audits can also serve as an medium-sized facilities to a simple method
excellent training activity for key personnel and for developed by the Center for Chemical Process
“guest” audit participants. Audits provide an Safety (CCPS), published in Essential Practices
opportunity for input from individuals in all levels for Managing Chemical Reactivity Hazards, to
of the organizations. Audit teams must also screen facilities for chemical reactivity hazards.
include at least one person with a good http://yosemite.epa.gov/oswer/ceppoweb.nsf/vwRe
understanding of the methods for identifying sourcesByFilename/flowchart.pdf/$File/flowchart.
chemical reactivity hazards. Team members pdf
should be familiar with the different elements of a
sound management system and be able to A Checklist for Inherently Safer Chemical
determine if each element is functioning as Reaction Process Design and Operation What
intended. The effectiveness of the training You Need to Know – 2004, 8 pages – Chemical
programs and the operating procedures should be a Center for Process Safety (CCPS).
focal point of the audit program.
CCPS has developed this free pamphlet as a
summary of basic principles for safe operation of
chemical reaction processes.
Reactive Material Hazards What You Need to
Know – 2001, 11 pages – Chemical Center for
Office of Emergency Management
Process Safety (CCPS).
CCPS has developed this free pamphlet to help
safety managers, chemists, and engineers
determine whether a process could have a chemical
reactivity hazard and what they should do to
prevent potential hazards.
SOME USEFUL WEBSITES
OSHA Reactives Alliance
OSHA Chemical Reactivity Safety
Mary Kay O’Connor Process Safety Center–
Reactive Chemical Research
National Oceanic and Atmospheric
Administration (NOAA) Chemical Reactivity
FOR MORE INFORMATION...
Contact the RCRA, Superfund & EPCRA
Call Center at:
(800) 424-9346 or (703) 412-9810
9 AM to 5 PM, Eastern Time
Visit the OEM Home Page at:
Office of Emergency Management