NFPA Journal - November/December 2020 - 39

In Compliance
area is protected by sprinklers. These
increases are cumulative, which means
if you have a starting MAQ of 120
gallons of a Class IB liquid in a storage cabinet that is sprinkler protected,
the MAQ increases to 480 gallons. It
is also important to note that Class I
liquids cannot be stored in a basement
and large quantities of flammable liquids require spill containment
measures. Certain occupancies, such
as business and educational occupancies, have special MAQ requirements
that are more restrictive of the quantity of liquid allowed.
In NFPA 30, Chapter 16 contains
several flow charts that can help users
determine what fire protection design
criteria and schemes they can utilize.
NFPA 30 enables fire protection to be
provided by a sprinkler system or a
foam-water sprinkler system.
Alcohol is considered a water-miscible liquid since it mixes easily with
water. According to the tables in
Chapter 16 of NFPA 30, water-miscible liquids that are less than 50
percent alcohol and stored in metal
containers can be treated as Class III
commodities, and if they are less than
20 percent alcohol, they can be treated
as Class I commodites. Since ABHR is
usually above 60 percent alcohol, these
generalizations don't apply. Instead,
NFPA 30 refers to tables within
Chapter 16 on the types of metal
containers and whether they must be
protected with a sprinkler or foam-water sprinkler system. The tables
include maximum storage height,
maximum ceiling height, required
aisle width, and required sprinkler
arrangement for metal containers, as
well as whether in-rack sprinklers are
required. A similar method can be
used for nonmetallic containers.
It is important to understand that
sprinkler systems are designed to
protect against certain hazards, and
that increasing those hazards can
cause your fire protection system to
be overwhelmed. This issue can be
addressed by developing a change
management plan that triggers safety
and compliance reviews when certain
changes occur.

While NFPA 13 usually contains
all of the requirements for installing
sprinkler systems for the storage of
flammable and combustible liquids, it
also works in harmony with NFPA 30 to
ensure sprinkler systems are designed
to help save people and property.
Brian O'Connor is a technical services engineer
at NFPA. NFPA members and AHJs can use the
Technical Questions tab to post queries on NFPA 13
at nfpa.org/13. To follow the progress on the
upcoming edition of the code, visit nfpa.org/13next.

NFPA 72

Fire alarms, signaling, and
emergency communication

Why pathway
survivability is still hot
By Wayne Moore
roposals have been

P

submitted for the 2022
edition of NFPA 72®,
National Fire Alarm and
Signaling Code®, and
pathway survivability is one area that
a lot of people want to change.
Pathway survivability is defined in
NFPA 72 as "the ability of any conductor, optic fiber, radio carrier, or other
means for transmitting system information to remain operational during
fire conditions." Performance requirements for survivability have been
included in the code since its first
edition in 1993. The 1999 edition was
the first to allow for three different
methods for achieving survivability,
while the 2019 edition includes the
following: "Fire alarm systems used
for partial evacuation and relocation
shall be designed and installed such
that attack by fire within a signaling
zone does not impair control and operation of the notification appliances
outside the signaling zone."
The requirement also applies to
circuits and equipment common to
more than one signaling zone. For
example, when a signaling line circuit

is used to control notification appliances in multiple notification zones,
it should be properly designed and
installed so that one fire cannot impair
more than one zone. Chapter 12 does
not require a specific pathway survivability method. Submitted changes to
this performance-based approach for
the 2022 edition were rejected by the
technical committee.
None of the Chapter 12 survivability requirements apply until another
section of NFPA 72, or another code,
requires survivability. For NFPA 72,
Chapter 24 requires specific levels of
survivability for all in-building fire
emergency voice/alarm communications systems (EVACS) where partial
evacuation or relocation occurs.
During the code cycles for the
2016 and 2019 editions of NFPA 72,
the requirements were changed to
permit Level 1, 2, or 3 survivability in
buildings constructed with less than
two-hour construction. During those
same cycles, the concept of Class N
and X circuits that are separated by
one-third of the diagonal of the notification zone was introduced again;
this would allow the installation to
permit Level 1, 2, or 3 survivability in
buildings constructed with less than
two-hour construction.
However, it has been determined
that the listing of either two-hour
fire-rated (circuit integrity) cable or
a two-hour electrical circuit protective system would need to be attached
to a concrete wall or floor assembly
constructed with a minimum two-hour
rating or as otherwise identified by
the UL fire-resistive cable systems
assembly. That means a pathway
survivability Level 2 or Level 3 that
uses circuit integrity cable or an electrical circuit protective system would
not meet the listing of those products if it was installed in a building
constructed with less than a two-hour
rating. In a fire, the wall or floor
assembly could fail, causing the pathway to fail. Both NFPA 72 and the UL
listing require all fire-rated cables and
systems to be supported per the manufacturer's installation instructions.
There are proposals to correct
N F PA . O R G / J O U R N A L * NFPA JOURNAL

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NFPA Journal - November/December 2020

Table of Contents for the Digital Edition of NFPA Journal - November/December 2020

Contents
NFPA Journal - November/December 2020 - Cover1
NFPA Journal - November/December 2020 - Cover2
NFPA Journal - November/December 2020 - 1
NFPA Journal - November/December 2020 - 2
NFPA Journal - November/December 2020 - 3
NFPA Journal - November/December 2020 - Contents
NFPA Journal - November/December 2020 - 5
NFPA Journal - November/December 2020 - 6
NFPA Journal - November/December 2020 - 7
NFPA Journal - November/December 2020 - 8
NFPA Journal - November/December 2020 - 9
NFPA Journal - November/December 2020 - 10
NFPA Journal - November/December 2020 - 11
NFPA Journal - November/December 2020 - 12
NFPA Journal - November/December 2020 - 13
NFPA Journal - November/December 2020 - 14
NFPA Journal - November/December 2020 - 15
NFPA Journal - November/December 2020 - 16
NFPA Journal - November/December 2020 - 17
NFPA Journal - November/December 2020 - 18
NFPA Journal - November/December 2020 - 19
NFPA Journal - November/December 2020 - 20
NFPA Journal - November/December 2020 - 21
NFPA Journal - November/December 2020 - 22
NFPA Journal - November/December 2020 - 23
NFPA Journal - November/December 2020 - 24
NFPA Journal - November/December 2020 - 25
NFPA Journal - November/December 2020 - 26
NFPA Journal - November/December 2020 - 27
NFPA Journal - November/December 2020 - 28
NFPA Journal - November/December 2020 - 29
NFPA Journal - November/December 2020 - 30
NFPA Journal - November/December 2020 - 31
NFPA Journal - November/December 2020 - 32
NFPA Journal - November/December 2020 - 33
NFPA Journal - November/December 2020 - 34
NFPA Journal - November/December 2020 - 35
NFPA Journal - November/December 2020 - 36
NFPA Journal - November/December 2020 - 37
NFPA Journal - November/December 2020 - 38
NFPA Journal - November/December 2020 - 39
NFPA Journal - November/December 2020 - 40
NFPA Journal - November/December 2020 - 41
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NFPA Journal - November/December 2020 - 43
NFPA Journal - November/December 2020 - 44
NFPA Journal - November/December 2020 - 45
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NFPA Journal - November/December 2020 - 61
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NFPA Journal - November/December 2020 - 78
NFPA Journal - November/December 2020 - 79
NFPA Journal - November/December 2020 - 80
NFPA Journal - November/December 2020 - Cover3
NFPA Journal - November/December 2020 - Cover4
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