Note: Descriptions are shown in the official language in which they were submitted.
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POWDERED COMPOSITION FOR THE GENERATION OF PERACETIC ACID
AND USE THEREOF TO SANITIZE SURFACES
The invention relates to a powdered composition for the generation of
peracetic acid in an aqueous solution at neutral pH level, and use thereof to
sanitize surfaces.
Introduction
Effective microbial growth control requires the use of broad spectrum
biocides which are both safe to use and environmentally benign. These
demands, and the prohibitive cost of developing new biocidal actives, combine
to
promote the use of highly effective agents with a proven history of
environmental
acceptance and safety. In this context, the peracid precursor, TAED (Tetra
Acetyl
Ethylene Diamine) is used extensively to activate peroxide and deliver broad
spectrum microbiocidal activity across a range of domestic, clinical and
industrial
applications.
Of the many classes of antimicrobial agents currently in use those based
on peroxygen are potentially the most environmentally acceptable. However,
existing peroxygen actives either lack rapid efficacy (e.g. hydrogen peroxide)
or
are potentially hazardous to use (e.g. preformed peracetic acid).
The Applicants have now discovered how to overcome these problems
enabling the promise of peroxygen based biocides to be realised. More
particularly, the Applicant have surprisingly found that reacting TAED with a
peroxygen source at near neutral pH provides a non-hazardous means of
generating peracetic acid, especially in situ in an aqueous solution,
according to
the following reaction scheme:
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0
O O /H
N ~ ~N\
+ 2 HOOH 2 CH30000_ + N
N
~_ /
O O
H
O
TAED Hydrogen Peracetic DASD
peroxide Anion
A preferred embodiment of the invention relates to a powdered composition
for the generation of peracetic acid in an aqueous solution at neutral pH
level,
said powdered composition comprising in combination:
a) a peroxygen source which generates hydrogen peroxide when
contacted by water; and
b) tetraacetylethylenediamine.
Another preferred embodiment of the invention relates to a powdered
composition as defined hereinbefore, wherein the peroxygen source is a persalt
whose the anion is a percarbonate, a perborate or a persulfate. More
preferably,
the peroxygen source may be sodium carbonate peroxyhydrate.
Another preferred embodiment of the invention relates to a powdered
composition as defined hereinbefore, wherein it further comprises a
sequestring
agent for the stabilization of the peracetic acid in the aqueous solution.
More
preferably, the sequestring agent may be a phosphonic acid based sequestrant,
or the sequestring agent may be nitriloacetic acid or phosphonic acid.
Another preferred embodiment of the invention relates to a powdered
composition as defined hereinbefore, wherein it further comprises a pH
adjuster
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for the adjustment of the pH of the aqueous solution between 6.5 and 8. More
preferably, the pH adjuster
= may be an organic acid such as, for example, acetic acid, citric acid or
formic acid, or
= may be sulfamic acid, phosphoric acid, sulfuric acid or hydrochloric acid.
Another preferred embodiment of the invention relates to a powdered
composition as defined hereinbefore, wherein it further comprises at least one
additive selected from the group consisting of surfactants and corrosion
inhibitors.
Another preferred embodiment of the invention relates to a use of a
powdered composition as defined hereinbefore,
= for the preparation of a peracetic solution which is bactericidal,
fungicidal,
sporicidal or virucidal; or
= for the preparation of a peracetic solution for the sanitation and
disinfection of surfaces, equipments, tanks, instruments in food plants,
water and wastewater treatment plants, dental and medical centers; or
= for the preparation of a peracetic solution for the control of viruses,
bacteria, yeast, mold, mycobacterium species, bacterial spores on
surfaces, instruments and equipments; or
= for the preparation of a peracetic solution for the sanitation and
disinfection of surfaces in contact with food, reservoirs, C.I.P. evaporators,
fillers, aseptic equipment and pasteurisers found in dairies, wineries,
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breweries and food, beverage and meat processing and packaging plants;
or
= for the preparation of a peracetic solution for the sanitation of water
tanks,
boilers, cooling tours and other equipments related to water and
wastewater treatment; or
= for the preparation of a peracetic solution which is a chemical sterilisant
for
surfaces, equipments and instruments in hospitals, dental clinics and
medical clinics; or
= for the preparation of a peracetic solution which is a chemical sterilisant
for
endoscopes;or
= for the preparation of a peracetic solution for the control of malodors,
diseases and microorganisms in farms, septic tanks, grease traps, drains
and agricultural sectors.
BRIEF DESCRIPTION OF DRAWINGS:
Particularly preferred embodiments of the present invention, which are
defined hereinafter, will be better understood with reference to the following
drawings in which:
= Figure 1 represents a container a 4 Kg container of Applicant's of BIOXY
S NEW prepared by Applicant's company.
= Figure 2 represents bactericidal activity of BIOXY S NEW against L.
pneumophila.
= Figure 3 represents soil tolerance of BIOXY S NEW
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= Figure 4 represents a peracid release profile of the formulation upon
dissolution when dosed at 27g/litre in warm water.
= Figure 5 represents the efficacy of a BIOXY S NEW / TAED activated
formulation similar to the one above (dosage 0.1 g/litre) against Legionella
p. at 20 C.
= Figure 6 represents peracid release profile of the formulation upon
dissolution when dosed at 16 g/litre in warm water (35 C).
= Figure 7 represents peracid release profile and pH profile of the
formulation upon dissolution when dosed at 16 g/litre in warm water
(35 C).
= Figure 8 represents a graph showing bactericidal efficacity (EN1276) of
peracetic acid solutions against E. coli under simulated ((dirty)) conditions
at 20 C.
= Figure 9 represents a graph showing bactericidal efficacity (EN1276) OF
Pre-formed peracetic acid solutions agains E. coli under simulated ((dirty))
conditions at 20 C.
= Figure 10 represents a graph showing bactericidal efficacity (EN1276) of
peracetic acid solutions against Staph. aureus under simulated ((dirty))
conditions at 20 C.
= Figure 11 represents a graph showing bactericidal efficacity (EN1276) OF
Pre-formed peracetic acid solutions against Staph. aureus under
simulated ((dirty)) conditions at 20 C.
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= Figure 12 represents a graph showing fungicidal activity (EN1650) of
TAED powder formulation against Candida albicans under simulated
<dirty conditions at 20 C.
= Figure 13 represents a graph showing bactericidal efficacity (BS EN1276)
of peracetic acid solutions against E. coli under simulated dirty
conditions at 20 C.
= Figure 14 represents a graph showing bactericidal efficacity (EN1276) of
peracetic acid solutions against Staph. Aureus under simulated dirty
conditions at 20 C.
= Figure 15 represents a graph showing fungicidal activity (EN 1650) of
TAED powder formulations against Candida albicans, under simulated
<<clean> and dirty conditions.
= Figure 16 represents a graph of the bactericidal efficacity of 10%
structured liquid, 15% peroxide liquid @ 1% concentration.
= Figure 17 represents a graph fo the efficacity of peracetic acid generated
from TAED against Bacilus subtilis endospores (suspension test).
= Figure 18 represents a graph of the efficacity of peracetic acid generated
from TAED against Bacilus subtilis Endospores (surface test).
= Figure 19 represents a graph of the efficacity of peracetic acid generated
from TAED against Bacillus subtilis endospores (suspension test).
DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
The Applicant's powdered composition for the generation of peracetic acid
in an aqueous solution at neutral pH level, which is hereinafter called BIOXY
S
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NEW, is preferably a powdered product composed of Sodium carbonate
peroxyhydrate, TAED (Tetra Acetyl Ethylene Diamine), citric acid,
sequestrants,
etc. This unique and particularly preferred powdered mixture allows to
generate
peracetic acid in water at neutral pH level. Unlike liquid peracetic acid sold
in the
market which are highly corrosive with offensive acetic acid smell, BIOXY S
NEW
generates peracetic acid (in-situ) once diluted with water at neutral pH level
with
no offensive odor and no induced corrosion.
Comparison BIOXY S NEW vs Liquid Peracetic Acid
Description BIOXY S - atomes Liquid Peracetic acid
Activity 10% active 5% active
Concentration 0.2% 0.4%
used- no rinse
2g/L=20g110L 4m1/L
Physical status Solid Liquid
Transportation Safe Hazardous
Odor No odor Offensive - Strong acetic acid
smell
pH Reacts with water to generate The pH is highly acidic
peracetic acid at neutral pH
levels
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Corrosion / No induced corrosion Extremely corrosive to surfaces
surfaces
Handling / Safe to handle Extremely dangerous to handle
employees
Storage Requires a limited place Requires large and a secured
space to prevent leaking
Chemical stability Stable Decomposes if exposed to heat
or organic materials
BIOXY S NEW as a Biocide
In comparison to many widely used biocides, peracetic acid has numerous
advantageous properties, possessing rapid broad spectrum biocidal activity
even
at low temperatures and in the presence of soil. As delivered, however,
preformed peracetic acid is unstable, potentially explosive, highly acidic and
as a
consequence highly corrosive. These properties make products containing
peracetic acid difficult to formulate for long term storage stability and
difficult to
handle and transport.
Performance Advantages
Non-hazardous and safe to use
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As all the reaction components are non-toxic and non-sensitising, BIOXY
S NEW based biocides are exceptionally safe to use. Unlike preformed peracetic
acid, chlorine, or glutaraldehyde, solutions of BIOXY S NEW release no
irritating
fumes or unpleasant odours and require minimal PPE.
Environmentally friendly
The system has a proven history of environmental acceptance as the
reaction components readily degrade to produce innocuous by-products in the
environment. This allows solutions to be easily and safely disposed of into
the
water supply.
Non-corrosive
As the strong oxidant can be generated and stabilised under neutral
conditions the corrosive effects of acidic, preformed, peracetic acids can be
mitigated.
Tailored peracid release
By manipulating the reaction chemistry the rate of peracetic acid release
can be effectively tailored to the application. Systems can be formulated to
give
an efficient and rapid release profile, which is a prerequisite for biocidal-
applications requiring short contact times. Alternatively, a slow sustained
peracid
release can be produced for those applications requiring continuous or
residual
activity.
Formulation flexibility
In its simplest form BIOXY S NEW provides a means of generating peracetic
acid in-situ and hence avoids the negatives associated with pre-formed
peracetic
acid products. In addition, since strong oxidant is only generated upon
dissolution
or reaction, the use of BIOXY S NEW allows the inclusion of otherwise non-
bleach
stable actives to enhance biocidal performance or biofilm/soil removal. This
allows both cleaning and disinfection to be achieved in a single operation.
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These benefits have enabled the introduction of BIOXY S NEW activated
biocides into the domestic, clinical and industrial environments with minimal
hazard to the user.
Broad spectrum microbicidal efficacy
BIOXY S NEW delivers effective broad spectrum activity over a wide range
of conditions, including varying pH, temperature and soil loading. As a
consequence, the system has found use in a range of biocidal products. For
example, BIOXY S NEW activated denture cleaners provide effective kill against
oral pathogens. In the medical arena, the sterilisation of surgical equipment
can
be rapidly accomplished to ensure the safety of staff and patients. While
BIOXY
S NEW activated laundry and automatic dish wash products provide high level
hygiene performance in the domestic and Industrial & Institutional sectors.
The system has proven Tuberculocidal, Pseudomonacidal and anti-Candidal
activity. As an example of bactericidal activity, Figure 2 shows the effect of
ppm
levels of BIOXY S NEW activated peroxide against L. pneumophila. The omission
of TAED from the peroxide containing solution resulted in the complete loss of
activity. While a moderate increase in the concentration of both actives was
found to give complete kill in less than 30 seconds.
Sterilant activity
BIOXY S NEW activated peroxide formulations have been shown to be
highly sporicidal at 20 C, delivering complete kill of a Log 7 inoculation of
B.
subtilis endospores within 5 minutes. This level of performance is sufficient
to
substantiate cold sterilant claims and ensure the complete destruction of
endospores and viruses. In addition, the use of BIOXY S NEW activated
peroxygen for chemothermal sterilisation would deliver effective sporicidal
and
virucidal activity at low levels of active.
Soil tolerance
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Soil is invariably present when biocidal activity is required and soil
tolerance is an important consideration in the selection of an effective
biocidal
system. Unlike many widely used commercial biocides, BIOXY S NEW activated
peroxide remains active in the presence of high soil levels. An effect which
is
clearly illustrated below, Figure 3, for a number of bacterial species. This
soil
tolerance is in part due to the sustained generation of biocidal species and
partly
to the ability of peracetic acid to remain biocidally active in the presence
of soil.
The robust nature of BIOXY S NEW activated peroxide is in contrast to chlorine
based biocides, whose performance is severely quenched by the presence of
soil.
BIOXY S NEW is traditionally formulated with a persalt to form solid,
concentrated, products with long shelf lives. This simplifies the logistics of
transportation and storage while minimising packaging and removes the need for
specialist handling/safety equipment.
Products may take the form of readily soluble powdered formulations
which generate biocidal solutions for immediate use. Alternatively,
concentrated
solutions of peracetic acid may be produced from such formulations by
dissolution in, for example, a holding tank. Such solutions, pre-reacted to
produce stable peracetic acid, may then be used over several working days.
BIOXY S NEW activated formulations may also be readily formed into tablets or
extruded products for the long-term, sustained release of actives.
CLINICAL STERILANT
Peracetic acid is a highly effective broad spectrum biocide used in a wide
range of applications. However the highly corrosive and flammable nature of
pre-
formed peracetic solutions causes many problems with handling and
transportation. In addition the use of co-actives in pre-formed peracetic
solutions
is not possible. Such problems are overcome by generating peracetic acid in-
situ
using BIOXY S NEW. The resultant solutions are non-corrosive and as peracetic
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acid is only generated upon dissolution, a wide range of co-actives can be
incorporated to further enhance biocidal and cleaning performance.
BIOXY S NEW delivers rapid sporicidal and virucidal activity and are highly
effective against a wide range of noscomial infection causing microorganisms
including MRSA, Pseudomonas aeruginosa and Escherichia coll.
BIOXY S NEW has significant advantages compared to other leading clinical
sterilants. They are microbiologically superior to glutaraldehyde and as
previously
mentioned, offer considerably more flexibility and safety in use than pre-
formed
peracetic solutions.
Figure 4 illustrates the peracid release profile of the formulation upon
dissolution when dosed at 27g/litre in warm water. Formulations dosed at this
level are highly sporicidal at 20 C, giving a Log 7 reduction of B. subtilis
endospores within 5 mins - performance sufficient to substantiate cold
sterilant
claims.
If required, the peracid release of the formulation can be tailored to meet
the application needs.
WATER TREATMENT
Peracetic acid is a highly effective broad spectrum biocide used in a wide
range of applications. However the highly corrosive and flammable nature of
pre-
formed peracetic solutions causes many problems with handling and
transportation. In addition the use of co-actives in pre-formed peracetic
solutions
is not possible. Such problems are overcome by generating peracetic acid in-
situ
at the point of use by using BIOXY S NEW. The resultant solutions are non-
corrosive and as peracetic acid is only generated upon dissolution, a wide
range
of co-actives can be incorporated to further enhance biocidal and cleaning
performance.
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The powdered formulation of BIOXY S NEW has been developed for use as
a disinfectant in a variety of water treatment applications. These include
cooling
towers, paper production plants, air conditioning units and swimming pool
disinfection.
Products based on this technology deliver rapid biocidal, algaecidal and
fungicida activity and are highly effective against a wide range of pathogens
including, Legionella pneumophila, Listeria monocytogenes and Pseudomonas
aeruginosa. They are also effective in the removal and prevention of biofilms.
Figure 5 illustrates the efficacy of a BIOXY S NEW / TAED activated
formulation similar to the one above (dosage 0.1g/litre) against Legionella p.
at
20 C. Along with powders, formulations can be dosed in tablet and sachet
format. Peracid release profile can be tailored to meet application needs. For
example, a rapid release can be generated when a knock down kill is required
or
a slower release sustainable over a period of several days can be provided
where longer term activity is necessary.
CLINICAL STERILANT
Peracetic acid is a highly effective broad spectrum biocide used in a wide
range of applications. However the highly corrosive and flammable nature of
pre-
formed peracetic solutions causes many problems with handling and
transportation. In addition the use of co-actives in pre-formed peracetic
solutions
is not possible. Such problems are overcome by generating peracetic acid in-
situ
using BIOXY S NEW. The resultant solutions are non-corrosive and as peracetic
acid is only generated upon dissolution, a wide range of co-actives can be
incorporated to further enhance biocidal and cleaning performance.
This powdered formulation has been developed for use as a clinical
sterilant or disinfectant - dependent on dosage.
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Products based on this technology deliver rapid sporicidal and virucidal
activity and are highly effective against a wide range of noscomial infection
causing microorganisms including MRSA, Pseudomonas aeruginosa and
Escherichia coli.
BIOXY S NEW / TAED activated products have significant advantages
compared to other leading clinical sterilants. They are microbiologically
superior
to glutaraldehyde and as previously mentioned, offer considerably more
flexibility
and safety in use than pre-formed peracetic solutions.
FIGURES 6 and 7 respectively illustrate the peracid release profile and pH
profile of the formulation upon dissolution when dosed at 16g/litre in warm
water
(35 C). Formulations dosed at this level are highly sporicidal at 20 C, giving
a
Log 7 reduction of B. subtilis endospores within 5 mins - performance
sufficient
to substantiate cold sterilant claims. If required, the peracid release of the
formulation can be tailored to meet the application needs. Peracid release in
cold
de ionised (20 C) water is also shown.
MEASUREMENT OF PERACETIC LEVELS
Levels of peracetic generated can be monitored in two ways, via
iodometric titration or the use of analytical test strips. The test strips are
manufactured by Merck and provide a rapid, convenient semi-quantative method
of determining peracetic levels (two formats available, 5-50 ppm and 100-
500ppm).
EFFICIENCY:
Figures 8 to 19 illustrate efficiency of BIOXY S NEW according to the
following
formulation and conditions.
Biocidal efficacity of TAED based formulations vs preformed peracetic acid
formulations
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Powder formulations: EN 1276 performance
Formulation tested.
B675 23.6%
(tetraacetylethylenediamine)
PBS1 54.5%
(sodium perborate monohydrate)
Citric Acid 18.3%
Sequestrant 1.80%
Surfactant 1.80%
pH of all tested solutions (Gram -ve & Gram +ve) adjusted to - 7.5
Powder formulations: EN 1650
= C. albicans
= 3 g/l BSA and 0.3 g/l BSA
= PAAH - 350 ppm - preformed PAAH
= PAAH - 350 ppm - TAED based formulations
= pH - 9Ø Formulations containing PCS and P BS1, pH altered with the
addition of citric acid. Preformed peracetic acid solutions, pH altered with
the addition of 5% sodium hydroxide.
Summary
= TAED based formulations give effective kill of both bacteria and fungi
using standard test methods.
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= Performance delivered by TAED-Persalt is similar to that shown by pre-
formed peracetic acid.
= Using a TAED based formulation provides the flexibility to add a range of
co-ingredients to breaden the efficacity of the formulation.
= TAED may be incorporated in a range of product formats.
Biocidal Efficacity of TAED based formulations
= Test Methods
BS EN 1276 - Quantitative suspension test for the evaluation of bactericidal
activity of chemical disinfectants and antiseptics used in food, industrial,
domestic, and institutional areas.
BE EN 1650 - Quantitative suspension test for the evaluation of fungicidal
activity of chemical disinfectants and antiseptics used in food, industrial
and
institutional areas.
Powder formulation: BS EN 1276 performance
Formulation tested.
B675 23.6%
(tetraacetylethylenediamine)
PBS1 54.5%
(sodium perborate monohydrate)
Citric Acid 18.3%
Sequestrant 1.80%
Surfactant 1.80%
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Formulations dosed to obtain peracetic acid levels of 50 ppm, 175 ppm, and 300
ppm.
Powder formulations: EN 1650
= C. a/bicans
= 3 g/l Bovine Serum Albumin (BSA) and 0.3 g/I BSA
= PAAH - 350 ppm - TAED based formulations
= pH - 9Ø Formulations containing PCS AND P BS1, pH altered with the
addition of citric acid.
Liquid formulation: EN 1276
= E. Coli, S. aureus, P. aeurginosa, E. hirae
= 3 g/1 BSA AND 0.3 g/l BSA
= Liquid formulation - pH 7
Conclusions
= TAED based formulations give effective kill both bacteria and fungi using
standard test methods.
= Using a TAED BASED formulation provides the flexibility to add a range of
co-ingredients to broaden the efficacity of the formulation.
= TAED may be incorporated in a range of product formats
= Activity much less affected by organic material than hypochlorite.
