NFPA Journal - March/April 2018 - 39

CODES, STANDARDS
AND COMPLIANCE

several factors: an analysis of the
materials being stored, a review of
product-specific commodity test data
(if available), a review of recent and
relevant commodity test data, a review
of commodity composition by weight
and volume, and a review of the annex
tables. Simply saying that a commodity
is similar to an item listed in the annex
is not adequate and can lead to an
under-designed sprinkler system.
Combine the importance of the
commodity classification assignment
with the aforementioned changes in
packaging and material selection, and
a review of these annex tables was warranted. The results of this review yielded
dozens of changes to the commodity
classifications for items listed in these
tables. For the bulk of these changes,
commodities originally considered Class
III (or group C plastics) or Class IV (or
group B plastics) commodities received
a bump in their original classification to
either Class IV or group A plastics. This
indicates that an increased density of
sprinkler protection is needed to control
these fires.
For designers and engineers who
determine what commodities are present for a given building, a close review
of these changes is an important first
step. Even if a project is governed by
an older edition of NFPA 13, designers
would be doing clients a disservice
from a risk perspective by not considering the latest edition of the standard.
Looking at the common materials
found in their clients' products to
determine if these materials have
changed commodity class will help
determine if design changes are needed
going forward. Since they are not in the
body of the standard and because NFPA
13 is not set up to require systems to be
upgraded to the latest standard, there
is no issue of retroactivity with these
changes.
That being said, several underwriters have expressed concern for certain
existing buildings, used to store/distribute goods, that underwent a change
in commodity class in these tables.
Consider an existing warehouse that

stores products made primarily of polyvinyl fluoride (PVF). The safety system
for this warehouse was designed to
the 2010 edition of NFPA 13 to protect
Class III commodities, which was the
assigned commodity class for PVF in
Annex A at that time. In 2016, PVF was
reclassified to a Group A plastic. While
the building and its sprinkler system
still comply with NFPA 13, since the
building is not required to be upgraded,
there is also a stock of products that
acts much differently in a fire event
than originally anticipated, and the
sprinkler system may not be able to
handle a fire involving those products.
Since there is no mandate to upgrade
the systems in these situations, they
would need to be decided on by the
owner and insurance representatives
on a case-by-case basis.
The selection of commodity classification is a critical part of the design.
Understanding how the recent changes
to the classification tables affects your
company and your clients can have a
huge impact on the risk being carried.
Matt Klaus is NFPA technical services lead for fire
protection engineering. NFPA members and AHJs
can use the Technical Questions tab to post queries
on NFPA 13 at nfpa.org/13.

NFPA 101

Life safety in new
and existing structures

Maximum allowable
quantities and
protection levels in
high-hazard industrial and
storage occupancies
By Kristin Bigda

n my years as a fire
protection engineer at
NFPA, I have found that
one of the most misunderstood phrases used
in the codes I work with is "maximum
allowable quantity," or MAQ. The term

I

"maximum" can imply that it is an
absolute value, but when users take a
closer look at the codes to understand
the application of an MAQ, they will
find that it is not in fact the maximum
value in all scenarios.
In the 2015 edition of NFPA 101®, Life
Safety Code®, the concept of an MAQ
was introduced as part of the classifications of high-hazard industrial and
high-hazard storage occupancies. Doing
so was an attempt to bridge the
gap between NFPA 101 and NFPA 1,
Fire Code, and the codes' respective
approaches to hazardous materials. The
concept was further refined in the 2018
edition of NFPA 101 with the inclusion
of a new scope statement to address
hazardous materials emergencies. This
was coupled with a new annex section
that outlines basic requirements from
the suite of NFPA documents that
govern hazard materials and will be
discussed further during the code's
2021 revision cycle.
NFPA 1 addresses the storage, use,
processing, handling, and on-site
transportation of flammable and combustible liquids, gases, and solids, as
well as other hazardous materials. To
fully understand the application of
the MAQ concept to these hazardous
materials, users must first recognize
several definitions from Chapter 3.
First, the term "maximum allowable
quantity" is defined as the quantity
of hazardous material permitted in a
control area. The term "control area"
is defined as a building or portion of a
building or outdoor area within which
hazardous materials are allowed to be
stored, dispensed, used, or handled
in quantities not exceeding the MAQ.
Finally, the term "hazardous material"
is defined as a chemical or substance
that is classified as a physical hazard
material or a health hazard material,
whether the chemical or substance is
in usable or waste condition. All three
of these terms work together when
applying the concept of the MAQ.
Jump ahead to Chapter 60 of NFPA
1, which provides the general requirements for occupancies containing
N F PA . O R G / J O U R N A L * NFPA JOURNAL

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Table of Contents for the Digital Edition of NFPA Journal - March/April 2018
