1
V:\
EFB\
Disposal\
Regs
­
2006\
Rinsing
Protocol
2006
OPPTS
8XX.
XXXX
Rinsing
Procedures
for
Dilutable
Pesticide
Products
in
Rigid
Containers
­
basic
testing
recommendations.

(
a)
Scope.

(
1)
Applicability.
This
guideline
describes
test
protocols
that
EPA
believes
will
generally
satisfy
residue
removal
performance
testing
requirements
of
the
Federal
Insecticide,
Fungicide,
and
Rodenticide
Act
(
FIFRA)
(
7
U.
S.
C.
136,
et
seq.).
It
addresses
testing
to
demonstrate
that
rigid
nonrefillable
containers
that
hold
dilutable
pesticide
products
can
be
effectively
rinsed
using
triple
rinsing
procedures,
such
that
a
fourth
rinse
shows
99.99%
product
removal.
The
guideline
also
includes
testing
for
pressure
rinsing
containers,
although
pressure
rinsing
testing
is
not
required
by
the
pesticide
container
regulations.

(
2)
Background.
The
source
material
used
in
developing
this
OPPTS
test
guideline
is
a
rinsing
protocol
developed
by
Formulogics
of
Princeton,
New
Jersey.
The
requirement
for
dilutable
pesticide
products
in
rigid
containers
to
achieve
99.99%
product
removal
is
required
by
40
CFR
Subpart
B
§
165.25.
In
1990,
Formulogics
conducted
a
container
rinsing
study
at
the
request
of
EPA.
The
study
was
designed
to
examine
pressure
and
triple
rinsing
for
a
number
of
containers
and
formulation
types.
Some
container
rinsing
studies
had
been
conducted
prior
to
the
Formulogics
study,
although
each
study
had
a
different
purpose
and
utilized
a
variety
of
collecting,
rinsing
and
reporting
procedures.
Therefore,
comparisons
between
these
studies
were
difficult
to
make.
To
eliminate
some
of
the
problems
of
previous
studies,
EPA
requested
that
a
protocol
be
developed
for
triple
and
pressure
rinsing.
Formulogics
developed
a
draft
protocol
and
circulated
the
draft
to
interested
parties
for
comment.
The
comments
were
considered
and
the
document
was
revised
and
released
on
September
6,
1990.

(
b)
Introduction.
This
guideline
addresses
testing
of
nonrefillable
pesticide
containers
for
their
ease
of
residue
removal
using
triple
rinse
or
pressure
rinse
procedures
prior
to
container
disposal
or
recycling.
This
guideline
applies
specifically
to
rigid
containers
that
are
small
enough
to
be
shaken,
which
is
designated
in
the
regulations
(
40
CFR
§
165.25(
f)(
1))
as
containers
with
capacities
less
than
or
equal
to
5
gallons
(
18.9
liters)
for
liquid
formulations
and
50
pounds
(
22.7
kilograms)
for
solid
formulations.
In
addition,
this
guideline
applies
specifically
to
dilutable
pesticides,
which
are
defined
in
the
regulations
(
40
CFR
§
165.25(
f)(
1))
as
pesticides
with
labeling
that
allows
or
requires
the
pesticide
product
to
be
mixed
with
a
liquid
diluent
prior
to
application.
This
guideline
recommends
tests
to
be
conducted
and
data
to
be
generated
and
held
by
the
registrant.
This
testing
protocol
can
be
used
to
determine
whether
a
container
and
formulation
achieve
99.99
percent
residue
removal.

(
c)
Test
Procedures
 
General.

(
1)
Selection
of
containers.
For
a
specific
pesticide
product,
three
unopened
containers
of
that
pesticide
product
with
the
same
production
lot
number
should
be
selected.

(
2)
Selection
of
collection
vessels.
Clean,
non­
contaminated
collection
vessels
should
be
available
for
containing
undiluted
product
and
rinsate
prior
to
analysis.

(
3)
Rinse
water.
The
source
of
rinse
water
is
not
restricted;
it
may
be
tap,
city,
well
or
any
other
commonly­
used
water.
Prior
to
the
test,
the
rinse
water
should
be
analyzed
for
the
specific
2
pesticide
active
ingredient
or
ingredients
that
are
being
tested
in
the
study.
The
water
should
not
contain
the
pesticide
active
ingredient
or
ingredients
being
tested
or
the
background
level
of
the
active
ingredient
should
be
such
that
it
does
not
interfere
with
the
rinsing
study.
The
analysis
of
the
water
should
be
conducted
prior
to
the
test.
It
is
not
necessary
to
analyze
the
water
each
time
a
sample
of
water
is
drawn.
The
purpose
of
this
provision
is
to
ensure
that
the
test
results
are
not
biased
due
to
the
presence
of
the
pesticide
active
ingredient
or
ingredients
in
the
rinse
water.

(
4)
Temperature
of
samples.
When
tested,
the
temperature
of
the
samples
should
be
23
degrees
Centigrade
±
3
degrees
C.

(
5)
Temperature
of
water.
The
water
used
in
the
rinse
study
should
be
23
degrees
Centigrade
±
3
degrees
C.

(
6)
Volume
measurement
for
rinse
water.
The
volume
of
rinse
water
that
is
added
to
the
containers
and
the
volume
of
rinsate
collected
should
be
determined.
The
rinse
water
volume
and
rinsate
volume
may
be
determined
by
either
volumetric
or
gravimetric
procedures
and
should
be
accurate
to
±
0.1
percent.

(
7)
Sampling
plans.
Three
different
sampling
plans
are
described.
The
plan
labeled
as
"
minimum"
is
an
option
requiring
the
minimum
amount
of
analytical
effort.
The
plan
labeled
as
"
acceptable"
is
somewhat
more
rigorous,
and
the
plan
labeled
as
"
good"
increases
the
analytical
burden
but
generates
the
best
overview
of
the
rinsing
process.
Any
of
the
sampling
plans
may
be
used.

(
d)
Triple
Rinsing
Test
Procedure.

(
1)
Preparation
of
container.
The
selected
container
should
be
opened
and
inverted
over
a
suitable
collection
vessel.
The
container
should
be
drained
according
to
the
process
described
in
section
(
d)(
2).
After
draining,
the
container
should
be
recapped
to
prevent
the
residue
from
evaporating.
If
possible,
the
rinsing
study
should
be
initiated
immediately
after
the
container
has
been
drained.
The
study
should
not
be
initiated
if
the
drained
container
is
allowed
to
remain
capped
and
standing
for
longer
than
thirty
(
30)
minutes.

(
2)
Draining
the
container.
The
container
should
be
drained
in
an
inverted
position
for
thirty
(
30)
seconds
when
removing
the
original
contents
or
rinsate
from
the
container.

(
i)
Timing.
The
thirty
(
30)
second
period
begins
once
the
flow
of
liquid
from
the
mouth
of
the
container
can
no
longer
be
described
as
a
continuous
stream.

(
ii)
Inverted.
The
word
inverted
should
be
interpreted
as
meaning
that
the
container
is
held
in
a
position
that
will
maximize
the
amount
of
liquid
that
will
drain
from
the
container
in
the
minimum
amount
of
time.
 

(
iii)
Specific
instructions
for
draining
material
from
containers
which
do
not
have
hollow
handles.
The
container
should
be
inverted
during
draining.
The
opening
of
the
container
defines
the
top.
The
container
should
be
held
so
the
face
of
the
container
opening
is
directed
towards
and
parallel
to
the
floor
at
the
start
of
the
drain
period.
At
5
seconds
into
the
drain
period,
the
container
should
be
rotated
clockwise
90
degrees
so
the
face
of
the
opening
is
perpendicular
to
the
floor.
The
container
should
be
held
in
this
3
position
for
5
seconds
and
then
rotated
back
to
the
original
inverted
position.
At
15
seconds
into
the
drain
period,
the
container
should
again
be
rotated
clockwise
90
degrees
so
the
face
of
the
opening
is
perpendicular
to
the
floor.
At
20
seconds
into
the
drain
period,
the
container
should
be
rotated
back
to
its
original
inverted
position
and
held
for
10
more
seconds.

(
iv)
Specific
instructions
for
draining
material
from
containers
with
a
hollow
handle
on
the
side.
The
container
should
be
inverted
during
draining.
The
opening
of
the
container
defines
the
top.
At
the
start
of
the
drain
period,
the
container
should
be
held
so
the
face
of
the
opening
is
directed
towards
and
parallel
to
the
floor
and
the
handle
is
on
the
left
hand
side
as
you
look
at
the
container.
At
5
seconds
into
the
drain
period,
the
container
should
be
rotated
clockwise
90
degrees
so
the
face
of
the
opening
is
perpendicular
to
the
floor.
The
handle
should
be
parallel
to
the
floor
and
on
the
upper
surface
of
container.
The
container
should
be
held
in
this
position
for
5
seconds
and
then
rotated
back
to
the
original
inverted
position.
At
15
seconds
into
the
drain
period,
the
container
should
again
be
rotated
clockwise
90
degrees
so
the
face
of
the
opening
is
perpendicular
to
the
floor.
At
20
seconds
into
the
drain
period,
the
container
should
be
rotated
back
to
its
original
inverted
position
and
held
for
10
more
seconds.

(
v)
Specific
instructions
for
draining
material
from
containers
with
a
hollow
handle
on
the
top.
The
container
should
be
inverted
during
draining.
The
opening
of
the
container
defines
the
top.
At
the
start
of
the
drain
period,
the
container
should
be
held
so
the
face
of
the
opening
is
directed
towards
and
is
parallel
to
the
floor.
The
opening
should
be
on
the
right
hand
side
as
you
face
the
container,
with
the
handle
oriented
along
a
line
running
left
to
right
and
parallel
to
the
floor.
At
5
seconds
into
the
drain
period,
the
container
should
be
rotated
clockwise
90
degrees
so
the
face
of
the
opening
is
perpendicular
to
the
floor.
The
handle
should
be
on
the
left
hand
side
and
perpendicular
to
the
floor.
The
container
should
be
held
in
this
position
for
5
seconds
and
then
rotated
back
to
the
original
inverted
position.
At
15
seconds
into
the
drain
period,
the
container
should
again
be
rotated
clockwise
90
degrees
so
the
face
of
the
opening
is
perpendicular
to
the
floor.
At
20
seconds
into
the
drain
period,
the
container
should
be
rotated
back
to
its
original
inverted
position
and
held
for
10
more
seconds.

(
3)
Adding
rinse
water.
Clean
rinse
water
should
be
added
to
the
drained
container.
The
volume
of
rinse
water
should
be
equivalent
to
25%
(
1/
4)
of
the
stated
volume
of
the
container
for
each
rinse
cycle.
The
volume
of
the
clean
rinse
water
that
is
added
to
the
container
should
be
recorded.
After
the
water
is
added,
the
cap
should
be
placed
back
on
the
container
before
shaking
the
container
according
to
the
instructions
in
section
(
d)(
4).

(
4)
Shaking
the
container.
The
container
should
be
shaken
by
hand
for
thirty
(
30)
seconds
per
rinse.
No
mechanical
devices
should
be
used.
4
(
i)
Initial
position.
To
start,
the
container
should
be
held
in
the
horizontal
plane
with
the
cap
or
top
portion
of
the
container
being
held
in
your
left
hand.

(
ii)
Container
facing
left.
For
the
first
ten
seconds,
the
container
should
be
shaken
vigorously
in
a
back
and
forth
(
left
to
right)
manner,
maintaining
the
container
parallel
to
the
floor.
The
container
should
be
shaken
at
a
rate
of
approximately
two
strokes
per
second
with
the
distance
of
the
stroke
between
4
and
6
inches.

(
iii)
Container
facing
down.
After
ten
seconds
and
in
a
continuous
motion,
the
container
should
be
rotated
90
degrees
so
the
cap
or
upper
portion
of
the
container
is
now
oriented
towards
the
floor.
The
container
should
be
shaken
vigorously
in
an
up
and
down
manner,
maintaining
the
container
perpendicular
to
the
floor.
The
container
should
be
shaken
at
a
rate
of
approximately
two
strokes
per
second
with
the
distance
of
the
stroke
between
4
and
6
inches.

(
iv)
Container
facing
up.
At
20
seconds,
the
container
should
be
rotated
so
the
cap
or
upper
portion
is
now
oriented
towards
the
ceiling.
The
container
should
be
shaken
vigorously
in
an
up
and
down
manner,
maintaining
the
container
perpendicular
to
the
floor.
The
container
should
be
shaken
at
a
rate
of
approximately
two
strokes
per
second
with
the
distance
of
the
stroke
between
4
and
6
inches
until
the
30
seconds
have
been
consumed.

(
5)
Draining
the
container
after
shaking.
The
cap
should
be
removed
from
the
container.
The
container
should
be
inverted
over
a
clean
collection
vessel
and
drained
for
thirty
(
30)
seconds
according
to
the
process
described
in
section
(
d)(
2).
The
volume
of
the
rinsate
collected
should
be
measured
and
recorded.

(
6)
Cleaning
the
threads.
After
draining
the
rinsate
from
the
container,
the
container
cap
and
the
threads
on
the
neck
of
the
container
should
be
wiped
clean.
If
a
clean
replacement
cap
is
available,
it
may
be
used
in
place
of
the
previous
cap.

(
7)
Additional
rinses.
The
procedures
in
sections
(
d)(
3)
through
(
d)(
6)
should
be
repeated
at
least
three
(
3)
more
times,
for
a
total
of
at
least
four
(
4)
rinses.

(
8)
Sampling
during
the
triple
rinse
procedure.
The
rinsate
should
be
sampled
using
good
laboratory
techniques.
Any
pesticide
residues
should
be
maintained
in
suspension
during
the
sampling
process.

(
i)
Minimum
sampling
plan.
The
fourth
rinsate
should
be
collected,
sampled
and
analyzed
according
to
section
(
d)(
9).
The
results
of
the
analysis
should
be
recorded.

(
ii)
Acceptable
sampling
plan.
The
third
and
fourth
rinsates
should
be
collected,
sampled
and
analyzed
according
to
section
(
d)(
9).
The
results
of
the
analyses
should
be
recorded.

(
iii)
Good
sampling
plan.
The
second,
third,
fourth
and
fifth
rinsates
should
be
collected,
sampled
and
analyzed
according
to
section
(
d)(
9).
The
results
of
the
analysis
should
be
recorded.
5
(
9)
Analysis.
The
samples
should
be
analyzed
for
the
pesticide
active
ingredient
or
ingredients
using
any
validated
analytical
procedure
suitable
for
the
analysis
of
the
active
ingredient(
s)
in
water.
If
no
extraction
or
concentration
procedures
are
employed
and
the
water
is
analyzed
directly,
the
method
should
have
a
level
of
sensitivity
of
0.5
ppm
or
lower.
The
following
information
should
be
recorded:

(
i)
Whether
the
rinsate
was
chemically
or
physically
treated
to
ensure
compound
stability
prior
to
analysis;
(
ii)
The
sensitivity
and
the
detection
limit
of
the
procedure;
and
(
iii)
Whether
the
water
samples
were
extracted.

(
10)
Waste
disposal.
The
rinsate
and
the
undiluted
pesticide
product
collected
in
this
study
should
be
discarded
utilizing
approved
disposal
procedures.

(
11)
Format
of
the
results.
The
results
of
the
rinsate
analysis
should
be
reported
as:
(
i)
the
rinsate
concentration
(
mg/
ml)
and
(
ii)
percent
removal.
Percent
removal
should
be
calculated
as
follows:

Final
rinsate
concentration
mg/
ml
___________________________
=
A
Original
concentration
mg/
ml
Percent
Removal
=
[
1.0
­
A
]
x
100
(
e)
Pressure
Rinsing
Procedure.

(
1)
Selection
of
pressure
rinsing
device.
A
rinsing
device
that
can
supply
a
pressure
of
at
least
40
pounds
per
square
inch
(
psi),
such
as
a
Jet
Rinse,
Quik­
Rinse
or
other
standard
pressure
rinsing
device
should
be
used.

(
2)
Water
pressure.
The
pressure
of
the
water
in
the
line
coming
into
the
lab
should
be
40
+
2
pounds
per
square
inch.

(
3)
Measuring
the
volume
of
water
discharged.
Before
beginning
the
pressure
rinse
process,
the
amount
of
water
that
is
discharged
by
the
pressure
rinsing
device
during
a
ten
(
10),
twenty
(
20)
and
thirty
(
30)
second
discharge
should
be
measured
and
recorded.

(
4)
Preparation
of
container.
The
selected
container
should
be
opened
and
inverted
over
a
suitable
collection
vessel.
The
container
should
be
drained
according
to
the
process
described
in
section
(
e)(
5).
After
draining,
the
container
should
be
recapped
to
prevent
the
residue
from
evaporating.
If
possible,
the
rinsing
study
should
be
initiated
immediately
after
the
container
has
been
drained.
The
study
should
not
be
initiated
if
the
drained
container
is
allowed
to
remain
capped
and
standing
for
longer
than
thirty
(
30)
minutes.

(
5)
Draining
the
container.
The
container
should
be
drained
in
an
inverted
position
for
thirty
(
30)
seconds
when
removing
the
original
contents
or
rinsate
from
the
container.
6
(
i)
Timing.
The
thirty
(
30)
second
period
begins
once
the
flow
of
liquid
from
the
mouth
of
the
container
can
no
longer
be
described
as
a
continuous
stream.

(
ii)
Inverted.
The
word
inverted
should
be
interpreted
as
meaning
that
the
container
is
held
in
a
position
that
will
maximize
the
amount
of
liquid
that
will
drain
from
the
container
in
the
minimum
amount
of
time.
 

(
iii)
Specific
instructions
for
draining
material
from
containers
which
do
not
have
hollow
handles.
The
container
should
be
inverted
during
draining.
The
opening
of
the
container
defines
the
top.
The
container
should
be
held
so
the
face
of
the
container
opening
is
directed
towards
and
parallel
to
the
floor
at
the
start
of
the
drain
period.
At
5
seconds
into
the
drain
period,
the
container
should
be
rotated
clockwise
90
degrees
so
the
face
of
the
opening
is
perpendicular
to
the
floor.
The
container
should
be
held
in
this
position
for
5
seconds
and
then
rotated
back
to
the
original
inverted
position.
At
15
seconds
into
the
drain
period,
the
container
should
again
be
rotated
clockwise
90
degrees
so
the
face
of
the
opening
is
perpendicular
to
the
floor.
At
20
seconds
into
the
drain
period,
the
container
should
be
rotated
back
to
its
original
inverted
position
and
held
for
10
more
seconds.

(
iv)
Specific
instructions
for
draining
material
from
containers
with
a
hollow
handle
on
the
side.
The
container
should
be
inverted
during
draining.
The
opening
of
the
container
defines
the
top.
At
the
start
of
the
drain
period,
the
container
should
be
held
so
the
face
of
the
opening
is
directed
towards
and
parallel
to
the
floor
and
the
handle
is
on
the
left
hand
side
as
you
look
at
the
container.
At
5
seconds
into
the
drain
period,
the
container
should
be
rotated
clockwise
90
degrees
so
the
face
of
the
opening
is
perpendicular
to
the
floor.
The
handle
should
be
parallel
to
the
floor
and
on
the
upper
surface
of
container.
The
container
should
be
held
in
this
position
for
5
seconds
and
then
rotated
back
to
the
original
inverted
position.
At
15
seconds
into
the
drain
period,
the
container
should
again
be
rotated
clockwise
90
degrees
so
the
face
of
the
opening
is
perpendicular
to
the
floor.
At
20
seconds
into
the
drain
period,
the
container
should
be
rotated
back
to
its
original
inverted
position
and
held
for
10
more
seconds.

(
v)
Specific
instructions
for
draining
material
from
containers
with
a
hollow
handle
on
the
top.
The
container
should
be
inverted
during
draining.
The
opening
of
the
container
defines
the
top.
At
the
start
of
the
drain
period,
the
container
should
be
held
so
the
face
of
the
opening
is
directed
towards
and
is
parallel
to
the
floor.
The
opening
should
be
on
the
right
hand
side
as
you
face
the
container,
with
the
handle
oriented
along
a
line
running
left
to
right
and
parallel
to
the
floor.
At
5
seconds
into
the
drain
period,
the
container
should
be
rotated
clockwise
90
degrees
so
the
face
of
the
opening
is
perpendicular
to
the
floor.
The
handle
should
be
on
the
left
hand
side
and
perpendicular
to
the
floor.
The
container
should
be
held
in
this
position
for
5
seconds
and
then
rotated
back
to
the
original
inverted
position.
At
15
seconds
into
the
drain
period,
the
container
should
again
be
rotated
clockwise
90
degrees
so
the
face
of
the
opening
is
perpendicular
to
the
floor.
At
20
seconds
into
the
drain
period,
the
container
should
be
rotated
back
to
its
original
inverted
position
and
held
for
10
more
seconds.

(
6)
Rinsing
the
container.
The
container
should
be
pressure
rinsed
as
follows.

(
i)
Remove
cap.
The
cap
should
be
removed
from
the
container.
7
(
ii)
Invert
container.
The
container
should
be
inverted
over
a
vessel
with
a
volume
sufficient
to
collect
at
least
sixty
(
60)
seconds
worth
of
rinsate.
Sufficient
room
between
the
container
and
the
collection
vessel
should
be
allowed
to
permit
the
sampling
of
the
rinsate.

(
iii)
Clean
the
threads.
Before
inserting
the
pressure
rinsing
device,
the
face
of
the
opening
and
the
threads
of
the
neck
of
the
container
should
be
wiped
clean.

(
iv)
Insert
the
pressure
rinsing
device.
The
pressure
rinsing
device
should
be
inserted
into
the
container
at
a
point
in
the
uppermost
surface
or
a
side
of
the
container
that
will
maximize
the
rinsing
of
the
internal
surfaces
of
the
container.
The
location
that
the
pressure
rinsing
device
is
inserted
into
the
container
should
be
recorded.

(
v)
Rinse
the
container.
The
water
to
the
pressure
rinsing
device
should
be
turned
on.
The
pressure
rinsing
device
should
be
moved
and
twisted
to
ensure
that
all
of
the
internal
surface
has
been
rinsed.

(
vi)
Length
of
rinse.
The
container
should
be
rinsed
for
at
least
thirty
(
30)
seconds
from
when
the
water
is
turned
on.
Measure
and
record
the
total
volume
of
rinsate
collected.

(
7)
Sampling
during
the
triple
rinse
procedure.
The
rinsate
should
be
sampled
using
good
laboratory
techniques.
Any
pesticide
residues
should
be
maintained
in
suspension
during
the
sampling
process.

(
i)
Minimum
sampling
plan.
The
last
two
seconds
(
29th
and
30th
seconds)
of
rinsate
should
be
collected,
sampled
and
analyzed
according
to
section
(
e)(
8).
The
volume
of
rinsate
collected
during
this
period
should
be
measured
and
recorded.
The
results
of
the
analysis
should
be
recorded.

(
ii)
Acceptable
sampling
plan.
The
rinsate
during
the
19th
 
20th
second
interval
and
the
29th
 
30th
second
interval
should
be
collected,
sampled
and
analyzed
according
to
section
(
e)(
8).
The
volume
of
rinsate
collected
during
each
time
period
should
be
measured
and
recorded.
The
results
of
the
analyses
should
be
recorded.

(
iii)
Good
sampling
plan.
The
rinsate
during
the
9th
 
10th
second
interval,
the
19th
 
20th
second
interval,
the
29th
 
30th
second
interval
and
the
39th
 
40th
second
interval
should
be
collected,
sampled
and
analyzed
according
to
section
(
e)(
8).
The
volume
of
rinsate
collected
during
each
time
period
should
be
measured
and
recorded.
The
results
of
the
analyses
should
be
recorded.

(
8)
Analysis.
The
samples
should
be
analyzed
for
the
pesticide
active
ingredient
or
ingredients
using
any
validated
analytical
procedure
suitable
for
the
analysis
of
the
active
ingredient(
s)
in
water.
If
no
extraction
or
concentration
procedures
are
employed
and
the
water
is
analyzed
directly,
the
method
should
have
a
level
of
sensitivity
of
0.5
ppm
or
lower.
The
following
information
should
be
recorded:

(
i)
Whether
the
rinsate
was
chemically
or
physically
treated
to
insure
compound
stability
prior
to
analysis;
(
ii)
The
sensitivity
and
the
detection
limit
of
the
procedure;
and
(
iii)
Whether
the
water
samples
were
extracted.
8
(
9)
Waste
disposal.
The
rinsate
and
the
undiluted
pesticide
product
collected
in
this
study
should
be
discarded
utilizing
approved
disposal
procedures.

(
10)
Format
of
the
results.
The
results
of
the
rinsate
analysis
should
be
reported
as:
(
i)
the
rinsate
concentration
(
mg/
ml)
and
(
ii)
percent
removal.
Percent
removal
should
be
calculated
as
follows:

Final
rinsate
concentration
mg/
ml
___________________________
=
A
Original
concentration
mg/
ml
Percent
Removal
=
[
1.0
­
A
]
x
100
