|
Halon Alternatives
Q. When was the production of halons banned?
Under the Clean Air Act (CAA), the U.S. banned the production and import
of virgin halons 1211, 1301, and 2402 beginning January 1, 1994 in
compliance with the Montreal Protocol On Substances That Deplete The
Ozone Layer. Recycled halon and inventories produced before January 1,
1994, are now the only sources of supply.
EPA's final rule published March 5, 1998, (63 FR 11084) bans the
formulation of any blend of two or more of these halons with one
exception. An exemption is provided for halon blends formulated using
recycled halon solely for the purpose of aviation fire protection,
provided that blends produced under this exemption are recycled to meet
the relevant purity standards for each individual halon. A fact sheet
summarizing this rule is also available from the Stratospheric Ozone
Protection Hotline.
Q. Must I now dismantle my halon fire protection
system?
No. It is legal to continue to use your existing halon system. It is
even legal to purchase recycled halon and halon produced before the
phaseout to recharge your system.
However, due to the fact that halons deplete the ozone layer, users are
encouraged to consider replacing their system and making their halon
stock available for users with more critical needs.
Q. Are there any federal laws on emissions of halons?
EPA's final rule published March 5, 1998 (63 FR 11084) prohibits the
intentional release of Halon 1211, Halon 1301, and Halon 2402 during the
testing, repairing, maintaining, servicing or disposal of halon-containing
equipment or during the use of such equipment for technician training.
The rule also requires appropriate training of technicians regarding
emissions reduction and proper disposal of halon and halon-containing
equipment. The rule became effective April 6, 1998.
Q. Where can I purchase recycled halon?
Recycled halon can be purchased from many halon and fire protection
equipment distributors or directly from owners who are decommissioning
their halon systems. In addition, the Halon Recycling Corporation (HRC)
may be able to provide information on such sellers.
Q. I am removing halon from my systems. I don't want to use it
again. What can I do with it?
You can: (1) make it available to critical users through the HRC; (2)
donate it to the Department of Defense Ozone Depleting Substances
Reserve (DoD bank); (3) return it to your distributor for resale; or (4)
send it to a halon recycler. The federal law on the disposal of halons
or halon-containing equipment is discussed in question C.6 below.
Q. What does SNAP stand for?
SNAP stands for Significant New Alternatives Policy program. EPA set up
the SNAP program under Section 612 of Title VI of the CAA, as amended in
1990.
Q. What is EPA doing under the SNAP program?
Under SNAP, EPA is evaluating substitute chemicals and alternative
technologies that companies want to use in place of the ozone-depleting
substances, to ensure that they won't cause greater damage to human
health and the environment than the ozone depleters that are being
replaced or other alternatives that are available. Based on this
evaluation, EPA maintains a list of acceptable substitutes and a list of
unacceptable substitutes.
Q. How does EPA decide whether a substitute is
acceptable or unacceptable?
EPA's decision on the acceptability of new substitutes proposed by
manufacturers is based primarily on the potential human health and
environmental risks posed by the substitutes as compared to (in the case
of halons) the halon being replaced, as well as to other substitute
fire-control agents. The screening of new substitutes is done separately
for each specific application, such as for a total flooding agent or for
use as a streaming agent. A listing of 'acceptable' does not imply that
the agent is necessarily effective for a particular fire hazard or site,
and users are advised to consult with a fire protection professional for
selection of appropriate agents.
Q. What are the most significant criteria for evaluating a
halocarbon halon substitute?
The key factor in assessing the safety of a halocarbon flooding agent is
cardiac sensitization. The amount of flooding agent to extinguish a fire
is compared to results of a standard protocol to determine an agent's
cardiosensitization levels. This is known as comparing the design
concentration to the No Observed Adverse Effect Level (NOAEL) and the
Lowest Observed Adverse Effect Level (LOAEL).
Q. I heard that HCFCs are not acceptable halon substitutes.
Under section 610(d) of the CAA, Congress requires EPA to ban the use of
a class of substances including HCFCs in all `pressurized dispensers,'
but allows EPA to grant exceptions from this ban in certain
circumstances. Portable fire extinguishers fall under the definition of
pressurized dispensers. In a final rule published by EPA on December 4,
1996 (61 FR 64424) EPA provided an exemption to the ban at CAA 610(d)
for portable non-residential fire extinguishers; thus, EPA allows the
sale and distribution of HCFCs for this use.
In addition, HCFCs in total flooding systems and fixed streaming systems
are not subject to the ban at CAA 610(d) because these systems don't
fall under the definition of pressurized dispensers.
For more specific guidance, contact the Stratospheric Ozone Protection
Hotline or the Nonessential Products Ban Program Coordinator at (202)
564-9729.
Q. What are the SNAP limitations on using a PFC (either C4F10,
C6F14 or C3F8) in the U.S.?
PFCs may only be used where no other agent is technically feasible due
to performance or safety requirements. The user must conduct an
evaluation of the other alternatives and must determine that they either
will not perform properly or that they will pose a risk to human health.
In addition, PFC use must meet the conditions discussed in question D.8
above.
Q. What is the SNAP status of alternative technologies such as
inert gases, water mist, and powdered aerosols?
Non-halocarbon systems are considered "alternative
technologies" and are subject to EPA SNAP review on the basis of
ozone depletion potential, global warming potential, toxicity,
flammability, and exposure potential. Several alternative technologies
have been listed acceptable, and some are subject to use conditions or
restrictions.
Q. What are the SNAP conditions on the use of inert gases,
which work by lowering the oxygen level?
Inert gas systems work by lowering the oxygen in a room to a level that
will not sustain combustion, while remaining high enough to sustain
human life.
SNAP requires that the oxygen level must not fall below 10% if employees
can egress the area within one minute; the oxygen level must be designed
to the 12% level if it takes longer than one minute to egress the area.
The CO2 level must not exceed 5%.
Three inert gases are listed acceptable by SNAP: IG-01, IG-55, and
IG-541. A fourth inert gas, IG-100, was proposed as an acceptable halon
substitute (with use restrictions) on Feb. 18, 1999; final action on
this agent is pending.
Q. Are there conditions on using water mist or water fog
systems?
EPA has listed water mist systems using potable water or natural sea
water as acceptable without use restrictions or conditions. However, any
system with an additive must be reviewed by EPA on a case-by-case basis.
Q. Can I use a powdered aerosol in a total flooding system in
an occupied area?
Powdered aerosol in total flooding systems has not undergone a
medical panel peer review for physiological effects, and thus they have
only been listed as acceptable in normally unoccupied areas.
Q. How can I obtain copies of the SNAP rules and notices?
The SNAP rules and notices can be ordered from the Stratospheric Ozone
Protection Hotline at (800) 296-1996 or (301) 614-3396. They can also be
ordered for a nominal fee from the Government Printing Office, (202)
512-1800 or fax (202) 512-2250.
Q. Where can I obtain additional information about the SNAP
program and likely alternatives for halon?
EPA's Stratospheric Ozone Protection Hotline
(800) 296-1996
(301) 614-3390
or
Halon Program Manager
Stratospheric Protection Division
U.S. EPA 6205J
Washington, DC 20460
(202) 564-9193
FAX (202) 565-2095
|
