March
15,
2004
1
Introduction
EPA's
risk
assessment
on
the
use
of
NAF
S
227

to
replace
halon
1301
as
a
total
flooding
agent
in
occupied
spaces,
is
summarized
in
this
document.
A
similarly
composed
agent,
NAF
S
125

has
been
previously
approved
through
the
SNAP
risk
screening
process
for
use
as
a
total
flooding
agent.
Both
agents
are
made
from
a
combination
of
0.15%
d­
limonene
and
an
HFC
(
Table
1).
NAF
S
125

was
found
safe
for
use
in
industrial
and
commercial
applications
by
trained
individuals
in
accordance
with
NFPA
2001
Standards.
Because
d­
limonene
has
previously
been
approved
for
use
in
a
total
flooding
agent
at
higher
concentrations
than
proposed
for
NAF
S
227

,
the
toxicity
and
atmospheric
integrity
of
this
ODS
substitute
will
not
be
discussed
further
in
this
document.

Table
1.
Composition
of
NAF
S
227

and
NAF
S
125

Constituent
Chemical
Formula
CAS
No.
Percent
of
Total
(
by
weight)
Design
Concentration
HFC­
227ea
(
heptafluoropropane)
CF3CHFCF3
431­
89­
0
99.85
NAF
S
227

(+)­
4­
isopropenyl­
1­
methylcyclohexene
(
d­
limonene)
C10H16
5989­
27­
5
0.15
±
0.05
7.5­
8.5%
v/
v
HFC­
125
(
pentafluoroethane)
CF3CHF2
354­
33­
6
99.85
±
0.1
NAF
S
125

(+)­
4­
isopropenyl­
1­
methylcyclohexene
(
d­
limonene)
C10H16
5989­
27­
5
0.15
±
0.05
9­
11.3%
v/
v
Similarly,
HFC­
227ea
(
FM­
200)
has
been
previously
approved
for
use
as
a
total
flooding
agent
by
EPA's
SNAP
program.
Use
of
HFC­
227ea
must
follow
the
requirements
in
the
latest
version
of
the
National
Fire
Protection
Association
(
NFPA)
2001
Standard
for
Clean
Agent
Fire
Extinguishing
Systems
which
establishes
safe
exposure
times
based
upon
PBPK
modeling.

The
design
concentration
of
NAF
S
227

is
7.5%
v/
v
for
Class
A
applications
and
8.5%
for
Class
B
applications.
Therefore,
the
exposure
at
end­
use
is
not
expected
to
be
of
concern
because
the
specified
design
concentration
is
below
the
maximum
concentration
for
a
five­
minute
safe
human
exposure
(
PBPK)
of
10.5%
v/
v.
This
risk
assessment
does
not
further
review
the
toxicity
or
atmospheric
integrity
of
HFC­
227ea
since
it
has
been
previously
approved
for
use
in
fire
suppression
formulations
under
the
SNAP
program.

Recommendations
for
Use
The
industry
set
workplace
guidance
level
for
HFC­
227ea
is
1000
ppm
and
the
8­
hour
TWA
set
by
AIHA
for
d­
limonene
is
30
ppm.
Therefore,
it
is
recommended
that
exposure
levels
during
manufacturing
for
March
15,
2004
2
HFC­
227ea
and
d­
limonene
should
be
kept
below
1000
ppm
and
30
ppm,
respectively,
on
an
8­
hour
TWA
basis.
Additionally,
EPA
recommends
the
following
for
establishments
installing
and
maintaining
total
flooding
systems:

°
adequate
ventilation
should
be
in
place
and
SCBA
equipment
should
be
available
if
ventilation
is
suspected
to
be
inadequate;
and
°
proper
personal
protection
equipment
must
be
worn
(
impervious
butyl
gloves,
eye
protection,
chemical
resistant
aprons,
long
sleeves,
and
safety
shoes);
and
°
all
spills
should
be
cleaned
up
immediately
in
accordance
with
good
industrial
hygiene
practices;
and
°
training
for
safe
handling
procedures
should
be
provided
to
all
employees
that
would
be
likely
to
handle
the
containers
of
NAF
S
227

or
extinguishing
units
filled
with
the
material.

Finally,
manufacturers
of
NAF
S
227

should
ensure
that
discharges
of
an
agent
within
an
enclosed
space
do
not
result
in
oxygen
concentrations
that
are
below
12%,
as
recommended
during
the
expert
panel
on
Physiological
Effects
of
Alternative
Fire
Protection
Agents
 
Hypoxic
Atmospheres
(
ICF
1997).

Conclusions
Use
of
NAF
S
227

as
a
total
flooding
agent
in
occupied
spaces
is
not
expected
to
pose
a
threat
to
atmospheric
integrity
or
human
health
as
long
as
NAF
S
227

extinguishers
are
only
used
by
specially
trained
and
selected
individuals.
It
is
also
recommended
that
NAF
S
227

only
be
used
in
industrial
and
commercial
application
and
in
accordance
with
the
safety
guidelines
in
the
latest
edition
of
the
NFPA
2001
Standard
for
Clean
Agent
Fire
Extinguishing
Systems.
In
addition,
it
is
suggested
that
potential
hazards
associated
with
the
use
of
NAF
S
227

,
as
well
as
handling
procedures
to
reduce
risk
resulting
from
these
hazards,
be
clearly
labeled
on
each
NAF
S
227

extinguisher.

References
ICF
1997.
Physiological
Effects
of
Alternative
Fire
Protection
Agents
­
Hypoxic
Atmospheres
Conference.
Stephanie
Skaggs
prepared
the
proceedings
of
the
conference
held
May
22,
1997
in
New
London,
CT.

NFPA,
2000.
NFPA
2001
Standards
for
Clean
Agent
Fire
Extinguishing
Systems,
2000
Edition.
The
Technical
Committee
on
Halon
Alternative
Protection
Options.
February
2000.
