United States
                        Environmental Protection
                        Agency
                           Office of Solid Waste
                           and Emergency Response
                           (5104)
EPA 55Q-F-9?-QQ2e
May 199?
f/EPA
FIRE  HAZARD FROM  CARBON
ADSORPTION DEODORIZING
SYSTEMS
                        The Environmental Protection Agency (EPA) is issuing this Alert as part of its ongoing effort to
                        protect human health and the environment by preventing chemical accidents. Under CERCLA,
                        section 104(e) and Clean Air Act CCAA), EPA has authority to conduct chemical accident
                        investigations. Additionally, in January 1995, the Administration asked the Occupational Safety
                        and Health Administration fOSHA) and EPA to jointly undertake investigations to determine
                        the root causefs) of chemical accidents and to issue public reports containing recommendations
                        to prevent similar accidents. EPA has created a chemical accident investigation team to work
                        jointly with OSHA in these efforts. Prior to the release of a full report, EPA intends to publish
                        Alerts as promptly as possible to increase awareness of possible hazards.  Alerts may also be
                        issued when EPA becomes aware of a significant hazard. It is important that facilities, SERCs,
                        LEPCs, emergency responders and others  review this information and take appropriate steps
                        to minimize risk.
                        PROBLEM
                               Activated carbon systems used to
                               adsorb vapors for control of
                               offensive odors may pose a fire
                        hazard when used for certain types of
                        substances, if proper procedures are not
                        followed.  In particular,  crude sulfate
                        turpentine, commonly produced in the
                        pulp and paper industry, can pose a fire
                        hazard if the adsorption  system is not
                        properly   designed  and  proper
                        procedures are  not  implemented.
                        Facilities should  take precautions to
                        avoid or mitigate these fire hazards.
                        ACCIDENTS
                           In a  1995 accident at a chemical
                           terminal facility, a fire and explosion
                           occurred involving three tanks of
                        crude sulfate turpentine.  The tanks
                        were connected to drums of activated
                        carbon for deodorizing.  The fire and
                        explosion damaged other storage tanks,
                        resulting in the release of toxic gases and
                        forcing a large-scale evacuation of area
                        residents.
                        Fires have occurred in the past in
                        activated carbon  systems used for
                        deodorizing crude sulfate turpentine. In
                        general, such fires have not had effects
                                     as serious as those reported in the 1995
                                     fire.  Serious  effects would not be
                                     expected if fires are confined to the
                                     activated carbon containers and do not
                                     spread to tanks containing flammable or
                                     combustible substances.

                                           Activated carbon is widely used to
                                           adsorb vapors to prevent their
                                           release  to the air.  For certain
                                     classes  of chemicals,  reaction or
                                     adsorption on the carbon surface is
                                     accompanied  by release  of  a large
                                     amount of heat that may cause hot spots
                                     in the carbon  bed. Such chemicals
                                     include organic sulfur compounds (e.g.,
                                     mercaptans), which may be found as
                                     impurities in crude sulfate turpentine
                                     and other materials.  Other classes of
                                     chemicals that may cause large thermal
                                     releases are ketones, aldehydes,  and
                                     some organic acids. Adsorption of high
                                     vapor  concentrations  of  organic
                                     compounds also can create hot spots. If
                                     flammable vapors are present, the heat
                                     released by adsorption or reaction on the
                                     surface of the carbon may create a  fire
                                     hazard (e.g., a fire may start if  the
                                     temperature reaches the autoignition
                                     temperature of the vapor and oxygen is
                                     present to support ignition).
Chemical Emergency Preparedness and Prevention Office
                                                   i Printed on recycled paper

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                            Fire Hazard from Carbon Adsorption Deodorizing Systems
                                   May 1997
The fire  hazards  of  carbon adsorption
deodorizing systems may increase at night. At
certain times (typically during the day), high
temperatures may lead to the expansion of vapor
in the system, and vapor is likely to exit to the
atmosphere. When temperatures drop (typically
at night), a slight vacuum may be created",
causing air to be drawn into the system. If the
carbon surface is very hot, because of the heat
generated by adsorption, air drawn in over the
carbon may provide the oxygen to start a fire.
4 If the potential exists for fires in the acti-
  vated carbon system, be sure the carbon
  containers are separated from containers of
  flammable or combustible substances and
  can be easily and rapidly removed in case
  the container becomes hot or catches fire.


4 If high concentrations of organic com-
  pounds may cause development of high
  temperatures, take steps to control the
  heating. Such steps may include diluting
  inlet air, time weighting the inlet concentra-
  tion to allow heat to dissipate, and pre-
  wetting the carbon.
     Facilities should be aware of the potential
     fire hazards of activated carbon systems for
     absorbing flammable vapors and take
steps to minimize these hazards. Actions that
may help to prevent fires include:


4- Follow the manufacturer's instructions for
  design and operation of activated carbon
  adsorption systems.


4 Ensure that a qualified engineer or technician
  supervises the design, construction, and
  operation of the carbon adsorption system.


4 Evaluate the composition of the vapors that
  will contact the carbon and heed the
  manufacturer's warnings about potential
  hazardous interactions with the carbon. If
  the vapor may contain organic sulfur
  compounds (e.g., vapor from crude sulfate
  turpentine), ketones, aldehydes, or organic
  acids, or if the vapor contains high concen-
  trations of organic compounds, consider the
  potential for development of hot spots on
  the carbon.
4 Test the action of the vapors on carbon for
  potential heat release before putting the
  carbon adsorption system into service, if
  possible reactions are not known.


4- If test results or known reactions with
  carbon indicate the potential for fires in the
  activated carbon system, design the system
  so that air does not enter the system over
  the carbon bed (e.g., install vacuum break-
  ers on the storage tanks).
4 Visually inspect activated carbon adsorp-
  tion systems frequently for hot spots and
  fires.


4 Before using an activated carbon adsorption
  system, ensure that safety systems are in
  place for fire prevention and mitigation,
  including flame arrestors to prevent the
  spread of fire from the carbon containers to
  the flammable chemical containers.
4 Ensure that flammable and combustible
  chemicals connected to activated carbon
  adsorption systems are handled in accor-
  dance with applicable regulations, codes,
  and standards.

     Some  references  that  may  contain
     information about the fire hazards of
     activated carbon adsorption systems and
methods of minimizing them are listed below.
Regulations applicable to such systems, and
codes and standards that may be relevant, are
also listed.
For more information consult the following:



Information on carbon adsorption systems for
crude sulfate turpentine can be found in W.A.
Harrell, J.O. Sewall, and  T.J. Walsh, "Control of
Malodorous Compounds by Carbon Adsorption,"
American Institute of Chemical Engineers, Loss
Prevention, Volume 12,1979, pp 124-127.

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                              Fire Hazard from Carbon Adsorption Deodorizing Systems
                                     May 1997
Manufacturers of activated carbon can provide
product literature until information on properties, safe
handling, and use.
flammable and combustible substances are included,
in DOT's Hazardous Materials Table [49 CFR
172.102].
Section 112(r) of the Clean Air Act focuses on
prevention of chemical accidents.  It imposes on
facilities with regulated substances or other extremely
hazardous substances a general duty to prevent and
mitigate accidental releases.  Accident prevention
activities include identifying hazards and operating
a safe facility.
EPA's Risk Management Program (RMP) Rule [40
CFR 68] is intended to  prevent and mitigate
accidental releases of listed toxic and flammable
substances.  Requirements under the RMP rule
include development of a hazard assessment, a
prevention program, and an emergency response
program.
Processes containing flammable gases and liquids
may be covered under the Occupational Safety and
Health Administration's (OSHA) Process  Safety
Management Standard, which establishes procedures
intended to protect employees  by preventing or
minimizing the consequences of chemical accidents
involving highly hazardous chemicals [29 CFR
1910.119].

OSHA also has a Standard for Flammable and
Combustible Liquids [29 CFR 1910.106].

Occupational Safety and Health Administration
Phone: (202) 219-8151  - Public Information
Web site: http://www.osha.gov
The Department of Transportation (DOT) regulates
transportation of activated carbon and other
flammable and combustible substances under its
Hazardous Materials Regulations. Activated carbon
and many combustible and flammable substances are
listed individually, and several categories of
                                                Department of Transportation
                                                Phone: (202) 366-5580 - Public Information
                                                Website: http://www.dot.gov
The National Fire Protection Association (NFPA) has
a code for flammable and combustible liquids that may
be adopted into law at the state or local level. NFPA
30 — Flammable and Combustible Liquids Code,
1996.

National Fire Protection Association
1 Batterymarch Park
P.O. Box 9101
Quincy, MA 02269-9101
Phone: (617)770-3000
Customer Sendee: 1 (800) 344-3555
Web site: http://www.nfpa.org
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                                          NOTICE

 The statements in this document are intended solely as guidance. This document does not substitute for EPA's or other
 agency regulations, nor is it a regulation itself. Site-specific application of the guidance may vary depending on process
 aetiwities, and may not apply to a given situation,  EPA may revoke, modify, or suspend this guidance in the future, as
 appropriate.

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