biocide optimization: an assessment of rapid kill...
TRANSCRIPT
Biocide Optimization: An Assessment of Rapid
Kill Preservatives and Two Novel Chemistries
Beth Ann Browne, Ph.D.
Dow Microbial Control
October 22, 2013
DOW CONFIDENTIAL - Do not share without permission
2
Outline
Paints Today
Speed vs. Endurance and Rapid-Kill vs. Long-Term
Preservatives
Benefits of Preservative Combinations
The Chemistries, Including Two Novel Active Ingredients:
MBIT (2-Methyl-1,2-Benzisothiazolin-3-one)
DBMAL (2,2-Dibromomalonamide)
Time-Kill and In-can Challenge Test Efficacy Data
Paint
Wash Water
Float Solution
Summary
DOW CONFIDENTIAL - Do not share without permission
Buffalo Grove,
Illinois, USA
DMC Center of
Excellence:
Microbiological
Methodology
Shanghai, China
Singapore Mumbai, India São Paulo,
Brazil
Dubai, United
Arab Emirates
Querétaro,
Mexico
Acknowledgements:
Colleagues from Dow Microbial Control Regional Microbiology Laboratories and
R&D Centers of Excellence
Buchs,
Switzerland
DMC Center of
Excellence:
Formulations
Spring House,
Pennsylvania, USA
DMC Center of
Excellence: Actives
Delivery
Soma, Japan
Warsaw, Poland
Altona, Australia
3
DOW CONFIDENTIAL - Do not share without permission
DOW CONFIDENTIAL - Do not share without permission
4
Today’s State of the Art
Paint Formulations…
Are more susceptible to microbial contamination due to:
Use of more sustainable ingredients, including naturally derived raw
materials
Lower volatile organic compound (VOC) levels
Increased water content
But, preservative choices are limited by:
Global registration status
Compatibility with final products and raw materials
Antimicrobial efficacy spectra, including resilient microorganisms
present in the manufacturing environment
Prevention of microbial contamination is a critical objective.
DOW CONFIDENTIAL - Do not share without permission
5
A Preservative Choice?
Stephen Kiprotich
2012 Olympic Marathon
2:08:01
Speed or Endurance?
Usain Bolt
2012 Olympic 100 Meter
9.63 seconds
Manufacturers’ answer:
Yes…BOTH!
DOW CONFIDENTIAL - Do not share without permission
6
There IS a Difference:
Preservative: An antimicrobial that provides long-term protection of a product to prevent it from becoming contaminated under repeated bacterial or fungal assaults.
Rapid Kill Antimicrobial: An antimicrobial that provides a rapid reduction in the number of viable microorganisms, but does not offer long-term protection.
Rapid Kill ≠ Long-Term Preservative
The Benefits of Combinations
Rapid Kill Chemistry:
Quick decontamination of raw materials and products
during the manufacturing process
Efficacy against resilient manufacturing isolates
Fill-in efficacy gaps of certain long-term preservatives
(ex: BIT and Pseudomonas sp.)
Reduce microbial load so that long-term preservative is
maintained…for the long-term
Long-term Chemistry:
Provides extended protection against contamination
Protects the product from customer use (and some misuse)
DOW CONFIDENTIAL - Do not share without permission
7
Rapid Kill + Long-Term Preservative = Robust Protection
DOW CONFIDENTIAL - Do not share without permission
8
The Chemistries (The Racers):
Speed
Typical
Human Usain Bolt The Cheetah
C
CC
N
O
NH2
BrBr
2,2-Di-bromo-3-nitrilo-propionamide
CMIT/MIT
SNH
O
BIT
MBIT
2,2-Dibromomalonamide
NH2 NH2
O O
Br
Br
Dibromomalonamide
NH2 NH2
O O
H2O
NH2 OH
O O
Malonamide
Malonamic acid
Malonic acid
CO2 and H
2O
H2O
NH2
O
Br
Br
Dibromoacetamide
H2O
OH
O
Br
Br
Dibromoacetic Acid
+ NH3
OH
O
H
O
+ 2 Br-
Glycolic Acid
Air
OH
O
OH
O
Oxalic Acid
H2O
Abiotic hydrolysis Nucleophilic biotic reactions
UV light
+ 2 Br-
+ NH3
+ NH3
S
N CH3
O
2-Methyl-1,2-
Benzisothiazolin-3-one
1,2-Benzisothiazolin-3-one
5- Chloro-2-Methy-4-
isothiazolin-3-one & 2-Methy-4-isothiazolin-3-one
DBNPA
DBMAL
DOW CONFIDENTIAL - Do not share without permission
9
Two New Biocidal Chemistries...
Speed
Usain Bolt The Cheetah
C
CC
N
O
NH2
BrBr
2,2-Di-bromo-3-nitrilo-propionamide
CMIT/MIT
SNH
O
BIT
MBIT
2,2-Dibromomalonamide
NH2 NH2
O O
Br
Br
Dibromomalonamide
NH2 NH2
O O
H2O
NH2 OH
O O
Malonamide
Malonamic acid
Malonic acid
CO2 and H
2O
H2O
NH2
O
Br
Br
Dibromoacetamide
H2O
OH
O
Br
Br
Dibromoacetic Acid
+ NH3
OH
O
H
O
+ 2 Br-
Glycolic Acid
Air
OH
O
OH
O
Oxalic Acid
H2O
Abiotic hydrolysis Nucleophilic biotic reactions
UV light
+ 2 Br-
+ NH3
+ NH3
S
N CH3
O
2-Methyl-1,2-
Benzisothiazolin-3-one
1,2-Benzisothiazolin-3-one
5- Chloro-2-Methy-4-
isothiazolin-3-one & 2-Methy-4-isothiazolin-3-one
DBNPA
DBMAL
Typical
Human
BIT vs. The Novel Active MBIT
DOW CONFIDENTIAL - Do not share without permission
10
0
100
200
300
400
500
Eff
ec
tive
Co
nc
en
tra
tio
n
(pp
m a
cti
ve
)
TiO2
CaCO3
BIT MBIT
> 500 > 500
250
125
MBIT is more efficacious against bacteria in two different
mineral slurry formulations:
TiO2
CaCO3
MBIT protects the TiO2 and CaCO3 slurries from four bacterial challenges over
27 days with 250 ppm and 125 ppm, respectively.
BIT vs. MBIT in Colorants
DOW CONFIDENTIAL - Do not share without permission
11
MBIT is more efficacious against bacteria after four challenges:
MBIT is more efficacious against yeast after three challenges:
0
100
200
300
400
500
Eff
ec
tive
Co
nc
en
tra
tio
n
(pp
m a
cti
ve
)
Blue Colorant
Yellow Colorant
Red Colorant
BIT MBIT
0
100
200
300
400
500
Eff
ec
tive
Co
nc
en
tra
tio
n
(pp
m a
cti
ve
)
Blue Colorant
Yellow Colorant
Red Colorant
BIT MBIT
DOW CONFIDENTIAL - Do not share without permission
12
Two New Biocidal Chemistries...
Speed
Usain Bolt The Cheetah
C
CC
N
O
NH2
BrBr
2,2-Di-bromo-3-nitrilo-propionamide
SNH
O
BIT
MBIT
2,2-Dibromomalonamide
NH2 NH2
O O
Br
Br
Dibromomalonamide
NH2 NH2
O O
H2O
NH2 OH
O O
Malonamide
Malonamic acid
Malonic acid
CO2 and H
2O
H2O
NH2
O
Br
Br
Dibromoacetamide
H2O
OH
O
Br
Br
Dibromoacetic Acid
+ NH3
OH
O
H
O
+ 2 Br-
Glycolic Acid
Air
OH
O
OH
O
Oxalic Acid
H2O
Abiotic hydrolysis Nucleophilic biotic reactions
UV light
+ 2 Br-
+ NH3
+ NH3
S
N CH3
O
2-Methyl-1,2-
Benzisothiazolin-3-one
1,2-Benzisothiazolin-3-one DBNPA
DBMAL
Typical
Human
DBNPA vs. the Novel Active DBMAL
DOW CONFIDENTIAL - Do not share without permission
13
DBMAL:
Derived from DBNPA
Formulated product is very stable (>2 years)
Stable in high pH solutions with persistent kill
Very effective in first market targeted– industrial water
treatment
Available in a liquid form
Expected EPA registration submission in 2014 for
Industrial Water Treatment
Currently being evaluated in other markets
Speed
DBMAL DBNPA
The Race: 100 Meters + 26.2 Miles
Measuring Preservative Performance Against
Bacteria in Paint, Wash Water, and a Float Solution
DOW CONFIDENTIAL - Do not share without permission
14
Time-Kill Assay
(The 100 Meter Sprint)
Used to determine the threshold concentration of biocide required to rapidly decontaminate contaminated materials.
Evaluates time-dependent bactericidal efficacy.
Procedure:
Test sample is inoculated with a pool of industrially relevant bacterial organisms at a concentration of 5 x 106 CFU/mL.
A series of biocide concentrations is established in separate aliquots of the spoiled product.
At specific time points, measured volumes of the sample are removed and biocide is neutralized.
Viable organisms are enumerated.
Time points: 0.25, 0.5, 1, 4, and 24 hours.
DOW CONFIDENTIAL - Do not share without permission
15
Bacterial Challenge Test
(The Marathon)
Used to determine the threshold concentration of biocide
required to protect the consumer product (ex: paint) from
bacterial spoilage.
Procedure:
A series of biocide concentrations are tested.
Test sample is challenged by inoculating it with a pool
of industrially relevant bacterial organisms at a
concentration of 5 x 106 CFU/mL.
At specific time points post inoculation and
subsequent reinoculation, measured volumes of the
sample are removed.
Viable organisms are enumerated.
DOW CONFIDENTIAL - Do not share without permission
16
Organisms and Scoring Scale
DOW CONFIDENTIAL - Do not share without permission
17
Bacteria Pool 1 (Laboratory strains)
•Alcaligenes faecalis (ATCC #8750)
•Pseudomonas aeruginosa (ATCC #10145)
• Pseudomonas aeruginosa (ATCC #15442)
• Staphylococcus aureus (ATCC #6538)
•Enterobacter aerogenes (ATCC #13048)
•Pseudomonas fluorescens (ATCC #17397) Plus…
Bacteria Pool 2 (Environmental Pseudomonas sp.)
• Pseudomonas aeruginosa (spoiled rheology modifier)
• Pseudomonas aeruginosa (spoiled process water)
• Pseudomonas aeruginosa (spoiled low VOC paint)
• Pseudomonas oleovorans (contaminated equipment)
Plating Results Score Approximate CFU/mL
No detectable colonies 0 < 1 x 101
1–9 colonies 1 1 x 101 - 9 x 101
10–99 colonies 2 1 x 102 – 9.9 x 102
100–300 colonies 3 1 x 103 - 3 x 103
>300 colonies (smear) 4 > 3 x 103
Scoring Scale:
Pass
Fail
Low VOC Paint
DOW CONFIDENTIAL - Do not share without permission 18
20% DBNPA product (ppm)/ DBNPA (ppm
a.i.)
24
hr.
Pre
-In
ocu
lati
on
Time Post Biocide Addition (hours)
Re-
Ino
cula
tio
n
Hours post Re-Inoculation
Re-
Ino
cula
tio
n
Hours post Re-Inoculation
Re-
Ino
cula
tio
n
Hours post Re-Inoculation
0.25 0.5 1 4 24 4 24 168 24 168 24 168
2000 / 400 2 2 1 0 0 4 2 0 3 0 3 0
1000 / 200 2 2 2 0 0 4 3 0 4 4 4 4
500 / 100 2 2 2 0 0 4 4 4 4 4 4 4
250 / 50 2 2 2 0 0 4 4 4 4 4 4 4
125 / 25 2 2 2 0 0 4 4 4 4 4 4 4
0 3 3 2 3 2 4 4 4 4 4 4 4
12% DBMAL product (ppm) / DBMAL (ppm
a.i.)
24
hr.
Pre
-In
ocu
lati
on
Time Post Biocide Addition (hours)
Re-
Ino
cula
tio
n
Hours post Re-Inoculation
Re-
Ino
cula
tio
n
Hours post Re-Inoculation
Re-
Ino
cula
tio
n
Hours post Re-Inoculation
0.25 0.5 1 4 24 4 24 168 24 168 24 168
5000 / 600 2 2 2 0 0 4 3 0 4 4 4 4
3333 / 400 2 2 2 0 0 4 3 4 4 4 4 4
1666 / 200 2 2 2 1 0 4 4 4 4 4 4 4
833 / 100 2 2 2 0 0 4 4 4 4 4 4 4
417 / 50 2 2 2 1 0 4 4 4 4 4 4 4
280 / 33.6 2 2 2 2 0 4 4 4 4 4 4 4
0 3 3 2 3 2 4 4 4 4 4 4 4
1.5% CMIT/MIT product (ppm) /
CMIT/MIT (ppm a.i.)
24
hr.
Pre
-In
ocu
lati
on
Time Post Biocide Addition (hours)
Re-
Ino
cula
tio
n Hours post
Re-Inoculation R
e-In
ocu
lati
on
Hours post Re-Inoculation
Re-
Ino
cula
tio
n Hours post
Re-Inoculation
0.25 0.5 1 4 24 4 24 168 24 168 24 168
1675 / 22.5 2 2 2 2 0 3 0 0 0 0 0 0
0 3 3 2 3 2 4 4 4 4 4 4 4
10% MBIT/CMIT/MIT product (ppm) /
MBIT/CMIT/MIT (ppm a.i.)
24
hr.
Pre
-In
ocu
lati
on
Time Post Biocide Addition (hours)
Re-
Ino
cula
tio
n
Hours post Re-Inoculation
Re-
Ino
cula
tio
n
Hours post Re-Inoculation
Re-
Ino
cula
tio
n
Hours post Re-Inoculation
0.25 0.5 1 4 24 4 24 168 24 168 24 168
3700 / 370 2 2 2 1 0 1 0 0 0 0 0 0
1850 / 185 2 2 2 1 0 3 0 0 4 4 4 4
0 3 3 2 3 2 4 4 4 4 4 4 4
DBNPA is fastest with efficacy
in 1-4 hours after the first
challenge.
DBMAL was fast, but did not
provide long-term efficacy.
CMIT/MIT showed efficacy in
24 hours and provided long-
term efficacy.
MBIT/CMIT/MIT combo
product was fast with efficacy
in 4 hours and provided long-
term protection.
Wash Water
DOW CONFIDENTIAL - Do not share without permission 19
DBNPA is fastest with efficacy
in 4 hours after the first
challenge.
DBMAL was fast (24 hours)
and provided long-term
efficacy.
CMIT/MIT was slow, but
provided long-term efficacy.
MBIT/CMIT/MIT combo
product was fast with efficacy
in 24 hours and provided
long-term protection.
20% DBNPA product (ppm)/ DBNPA (ppm a.i.)
24
hr.
Pre
-In
ocu
lati
on
Time Post Biocide Addition (hours)
Re-
Ino
cula
tio
n
Time Post Re-Inoculation (hours)
0.25 0.5 1 4 24 120 168 4 24 168
2000 / 400 4 4 3 0 0 0 0 4 1 0
1000 / 200 4 4 4 0 0 0 0 4 3 1
500 / 100 4 4 4 1 0 0 0 4 4 1
250 / 50 4 4 4 2 0 0 0 4 4 4
125 / 25 4 4 4 4 0 0 0 4 4 4
0 4 4 4 4 4 4 4 4 4 4
12% DBMAL product (ppm) / DBMAL (ppm a.i.)
24
hr.
Pre
-In
ocu
lati
on
Time Post Biocide Addition (hours)
Re-
Ino
cula
tio
n
Time Post Re-Inoculation (hours)
0.25 0.5 1 4 24 120 168 4 24 168
5000 / 600 4 4 4 4 0 0 0 4 0 0
3333 / 400 4 4 4 3 0 0 0 4 1 1
1666 / 200 4 4 4 4 0 0 0 4 2 1
833 / 100 4 4 4 4 0 0 0 4 2 1
417 / 50 4 4 4 4 1 0 1 4 4 4
280 / 33.6 4 4 4 4 4 4 4 4 4 4
0 4 4 4 4 4 4 4 4 4 4
1.5% CMIT/MIT product (ppm) / CMIT/MIT (ppm a.i.)
24
hr.
Pre
-In
ocu
lati
on
Time Post Biocide Addition (hours)
Re-
Ino
cula
tio
n Time Post Re-
Inoculation (hours)
0.25 0.5 1 4 24 120 168 4 24 168
1675 / 22.5 4 4 4 4 3 0 0 4 3 0
0 4 4 4 4 4 4 4 4 4 4
10% MBIT/CMIT/MIT product (ppm) / MBIT/CMIT/MIT (ppm
a.i.)
24
hr.
Pre
-In
ocu
lati
on Time Post Biocide Addition (hours)
Re-
Ino
cula
tio
n
Time Post Re-Inoculation (hours)
0.25 0.5 1 4 24 120 168 4 24 168
3700 / 370 4 4 4 4 1 0 0 4 0 0
1850 / 185 4 4 4 4 0 0 0 4 2 0
0 4 4 4 4 4 4 4 4 4 4
Float Solution
DOW CONFIDENTIAL - Do not share without permission 20
DBNPA is fastest with efficacy
in 1-4 hours after the first
challenge.
DBMAL was fast (24 hours)
and provided long-term
efficacy.
CMIT/MIT was slow, but
provided long-term efficacy.
MBIT/CMIT/MIT combo
product was fast with efficacy
in 24 hours and provided
long-term protection.
20% DBNPA product (ppm)/ DBNPA (ppm a.i.)
24
hr.
Pre
-In
ocu
lati
on
Time Post Biocide Addition (hours)
Re-
Ino
cula
tio
n
Time post Re-Inoculation (hours)
0.25 0.5 1 4 24 120 168 4 24 168
2000 / 400 4 4 0 0 0 0 0 0 0 0
1000 / 200 4 4 3 0 0 0 0 0 1 0
500 / 100 4 4 4 0 0 0 0 4 0 0
250 / 50 4 4 4 0 0 0 0 4 4 4
125 / 25 4 4 4 0 0 0 0 4 4 4
0 4 4 4 4 4 4 4 4 4 4
12% DBMAL product (ppm) / DBMAL (ppm a.i.)
24
hr.
Pre
-In
ocu
lati
on
Time Post Biocide Addition (hours)
Re-
Ino
cula
tio
n
Time post Re-Inoculation (hours)
0.25 0.5 1 4 24 120 168 4 24 168
5000 / 600 4 4 4 4 0 0 0 4 0 0
3333 / 400 4 4 4 4 0 0 0 4 0 0
1666 / 200 4 4 4 4 0 0 0 4 0 0
833 / 100 4 4 4 4 0 0 0 4 0 0
417 / 50 4 4 4 4 0 0 0 4 1 1
280 / 33.6 4 4 4 4 1 1 1 4 2 4
0 4 4 4 4 4 4 4 4 4 4
1.5% CMIT/MIT product (ppm) / CMIT/MIT (ppm a.i.)
24
hr.
Pre
-In
ocu
lati
on
Time Post Biocide Addition (hours)
Re-
Ino
cula
tio
n Time post Re-
Inoculation (hours)
0.25 0.5 1 4 24 120 168 4 24 168
1675 / 22.5 4 4 4 4 3 0 0 4 2 0
0 4 4 4 4 4 4 4 4 4 4
10% MBIT/CMIT/MIT product (ppm) / MBIT/CMIT/MIT (ppm
a.i.)
24
hr.
Pre
-In
ocu
lati
on
Time Post Biocide Addition (hours)
Re-
Ino
cula
tio
n
Time post Re-Inoculation (hours)
0.25 0.5 1 4 24 120 168 4 24 168
3700 / 370 4 4 4 4 0 0 0 4 0 0
1850 / 185 4 4 4 4 0 0 0 4 0 0
0 4 4 4 4 4 4 4 4 4 4
Performance Trends
DOW CONFIDENTIAL - Do not share without permission
21
DBMAL
DBNPA
CMIT/MIT
Speed Endurance
MBIT/CMIT/MIT
Rapid Kill Long-term
Preservation
An In-Depth Look at Paint
Preservation with the
MBIT/CMIT/MIT
Combination
DOW CONFIDENTIAL - Do not share without permission
22
23
High-Throughput
Challenge Evaluations
Validated to standard agar plate tests Generate large amounts of comparative performance data
Quickly evaluate combinations for synergy or antagonism
Important for biocide optimization studies as VOC content becomes lower In-can preservative plus co-biocide
Compare lab strains vs. manufacturing facility contaminants
DOW CONFIDENTIAL - Do not share without permission
More than 13,000 data points on
biocidal actives,
concentrations, or active ratios
High-Throughput Screening –
A Day’s Work
vs.
Limited number
of data points 24
DOW CONFIDENTIAL - Do not share without permission
Performance in Paint Sample pH 8.52
Against Bacteria
25
Day 1 Day 2 Day 1 Day 4 Day 1 Day 6 Day 1 Day 6 Day 13
4000 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
3077 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.5
2367 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.5
1821 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3.5 8.0
1401 0.0 0.0 0.0 0.0 0.0 2.5 5.5 8.0 6.5
1077 0.0 0.0 0.0 0.0 0.0 7.0 8.0 7.0 7.0
829 0.0 0.0 0.0 0.0 0.5 8.0 7.5 7.5 6.5
637 0.0 0.0 0.0 0.0 3.0 8.0 7.0 6.5 6.5
0 0.0 0.0 0.0 0.0 7.2 7.6 7.2 7.1 6.7
BIOBAN 557
(ppm)
Cycle I
Ch
alle
nge
1 (
5 x
106
CFU
/ml)
Ch
alle
nge
2 (
5 x
106
CFU
/ml)
Cycle IV
Ch
alle
nge
3 (
5 x
106
CFU
/ml)
Cycle IIICycle II
Ch
alle
nge
4 (
5 x
106
CFU
/ml)
Day 1 Day 2 Day 1 Day 4 Day 1 Day 6 Day 1 Day 6 Day 13
2500 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
1923 0.0 0.0 0.0 0.0 0.0 7.5 7.5 7.0 7.0
1479 0.0 0.0 0.0 0.0 3.5 7.5 7.5 6.5 6.5
1138 0.0 0.0 0.0 0.0 4.0 6.0 7.0 7.0 6.5
875 0.0 0.0 0.0 0.0 6.0 7.5 7.0 7.0 7.0
673 0.0 0.0 0.0 0.0 6.0 7.0 7.0 7.0 7.0
518 0.0 0.0 0.0 0.0 6.5 7.0 7.0 7.0 7.5
398 0.0 0.0 0.0 0.0 7.0 7.0 6.0 7.0 6.0
0 0.0 0.0 0.0 0.0 7.2 7.6 7.2 7.1 6.7
Cycle IIICycle IICycle IC
hal
len
ge 2
(5
x 1
06 C
FU/m
l)
Ch
alle
nge
1 (
5 x
106
CFU
/ml)
Ch
alle
nge
4 (
5 x
106
CFU
/ml)
ROCIMA BT 2S
(ppm)
Cycle IV
Ch
alle
nge
3 (
5 x
106
CFU
/ml)
Day 1 Day 2 Day 1 Day 4 Day 1 Day 6 Day 1 Day 6 Day 13
1675 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
1288 0.0 0.0 0.0 0.0 0.0 0.0 0.5 4.0 5.0
991 0.0 0.0 0.0 0.0 0.0 0.0 5.0 6.5 7.5
762 0.0 0.0 0.0 0.0 0.0 2.5 7.5 8.0 7.0
586 0.0 0.0 0.0 0.0 0.0 1.5 7.5 7.5 7.0
451 0.0 0.0 0.0 0.0 0.5 6.0 7.0 8.0 7.0
347 0.0 0.0 0.0 0.0 1.0 7.5 7.5 7.5 7.5
267 0.0 0.0 0.0 0.0 5.0 7.0 7.0 7.5 6.5
0 0.0 0.0 0.0 0.0 7.2 7.6 7.2 7.1 6.7
Ch
alle
nge
4 (
5 x
106
CFU
/ml)
Cycle IVKATHON LX 1.5%
(ppm)
Ch
alle
nge
1 (
5 x
106
CFU
/ml)
Cycle I
Ch
alle
nge
2 (
5 x
106
CFU
/ml)
Cycle II Cycle III
Ch
alle
nge
3 (
5 x
106
CFU
/ml)
Passing at 2367 ppm product;
213 ppm MBIT
11.8 ppm CMIT,
11.8 ppm MIT
(23.6 ppm total CMIT/MIT)
Passing at 2500 ppm product;
475 ppm BIT (EPA max)
Passing at 1675 ppm product;
25 ppm CMIT/MIT (EPA max)
DOW CONFIDENTIAL - Do not share without permission
10%
MBIT/CMIT/MIT
Product (ppm)
19% BIT Product
(ppm)
1.5% CMIT/MIT
Product
(ppm)
No margin of error with
industrial hygiene.
No margin of error with
industrial hygiene.
Passing with a
comfortable margin.
Paint pH 9.03 Against Customer-
Specific Yeast and Standard Mold
DOW CONFIDENTIAL- Do not share without permission
26
19% BIT Product (ppm) / BIT (ppm a.i.)
Ch
alle
nge
1
(5
x 1
06 CFU
/ml)
Cycle I
Ch
alle
nge
2
(5
x 1
06 CFU
/ml)
Cycle II
Ch
alle
nge
3
(5
x 1
06 CFU
/ml)
Cycle III
Day 1
Day 7
Day 1
Day 8
Day 1
Day 6
2000 / 380 4 2 4 0 4 2
1250 / 237.5 4 2 4 2 4 2
500 / 95 4 4 4 2 4 4
0 4 4 4 4 4 4
10% MBIT/CMIT/MIT Product (ppm) / MBIT/CMIT/MIT
(ppm a.i.)
Ch
alle
nge
1
(5
x 1
06 C
FU/m
l)
Cycle I
Ch
alle
nge
2
(5
x 1
06 C
FU/m
l)
Cycle II
Ch
alle
nge
3
(5
x 1
06 C
FU/m
l)
Cycle III
Day 1
Day 7
Day 1
Day 8
Day 1
Day 6
3700 / 370 0 0 0 0 0 1
2700 / 270 0 0 1 0 0 0
1800 / 180 0 1 1 0 0 0
900 / 90 0 1 1 1 0 1
0 4 4 4 4 4 4
1.5% CMIT/MIT Product (ppm) / CMIT/MIT (ppm a.i.)
+ 95 ppm BIT
Ch
alle
nge
1
(5
x 1
06 CFU
/ml)
Cycle I
Ch
alle
nge
2
(5
x 1
06 CFU
/ml)
Cycle II C
hal
len
ge 3
(5 x
106 C
FU/m
l)
Cycle III
Day 1
Day 7
Day 1
Day 8
Day 1
Day 6
1675 0 0 4 2 4 4
1200 0 0 4 2 4 4
900 0 0 4 2 4 4
600 0 0 4 2 4 4
0 4 4 4 4 4 4
81 ppm MBIT
9 ppm CMIT/MIT
90 ppm total
380 ppm BIT
25 ppm CMIT/MIT
95 ppm BIT
120 ppm total
Passed
Failed
Failed
Summary (1 of 2)
Paints today are more susceptible to microbial contamination due to
more sustainable ingredients, lower VOC levels, and increased
water content.
Preservative choices are limited due to global registration status,
compatibility with final products and raw materials, and antimicrobial
efficacy spectra.
Product quality is critical for manufacturers and consumers.
Rapid-kill antimicrobials (ex. DBNPA) ≠ long-term preservatives.
Rapid-kill biocidal actives are important for reducing stress on the
long-term preservatives.
DOW CONFIDENTIAL - Do not share without permission
27
Summary (2 of 2)
Two novel biocidal actives were evaluated:
MBIT and DBMAL.
MBIT displayed improved efficacy over BIT.
However, DBNPA is faster than DBMAL.
The combination of MBIT/CMIT/MIT provided rapid-kill and long-
term preservation in paint, wash water, and a float solution.
MBIT/CMIT/MIT was effective against bacteria, as well as fungi
(yeast and mold). Yeast contamination is increasingly becoming an
issue for paint formulations.
DOW CONFIDENTIAL - Do not share without permission
28
DOW CONFIDENTIAL- Do not share without permission
29
Notice: No freedom from infringement of any patent owned by Dow or
others is to be inferred. Because use conditions and applicable laws may
differ from one location to another and may change with time, Customer is
responsible for determining whether products and the information in this
document are appropriate for Customer's use and for ensuring that
Customer's workplace and disposal practices are in compliance with
applicable laws and other government enactments. The product shown in
this literature may not be available for sale and/or available in all
geographies where Dow is represented. The claims made may not have
been approved for use in all countries. Dow assumes no obligation or
liability for the information in this document. References to “Dow” or the
“Company” mean the Dow legal entity selling the products to Customer
unless otherwise expressly noted. NO WARRANTIES ARE GIVEN; ALL
IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE ARE EXPRESSLY EXCLUDED.