Hazardous or toxic waste destruction or containment – Containment – Solidification – vitrification – or cementation
Reexamination Certificate
2000-01-05
2002-04-09
Griffin, Steven P. (Department: 1754)
Hazardous or toxic waste destruction or containment
Containment
Solidification, vitrification, or cementation
Reexamination Certificate
active
06369288
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a chemical warfare agent decontamination solution. More particularly, the decontamination solution includes a peroxygen component and bleach activator to generate a peroxycarboxylic acid in-situ. Most particularly, the decontaminating solution contains a microemulsion for applying a formed peroxycarboxylic acid. The decontaminating solution is useful in neutralizing chemical and biological warfare agents.
2. Brief Description of the Related Art
Methods for decontamination of chemical warfare agents, which include a variety of organophosphorus and organosulfur compounds, are known in the art. However, these known methods use compositions which have certain undesirable properties, including corrosiveness, flammability and toxicity. For example, hypochlorite formulations are very corrosive and toxic. Additionally, application of the hypochlorite decontaminant often requires substantial scrubbing for removal and destruction of the chemical warfare agent, a procedure which limits its use.
One decontaminant, Decontamination Solution 2 (DS2) used by the United States Army, is useful against a variety of chemical and biological warfare agents. DS2 contains 70% diethylenetriamine, 28% ethylene glycol monomethyl ether and 2% sodium hydroxide. However, DS2 spontaneously ignites upon contact with hypochlorites and hypochlorite-based decontaminants. Further, DS2 may cause corrosion to aluminum, cadmium, tin and zinc after prolonged contact, and softens and removes paint. Similar corrosion and human toxicity problems exist with the bleach decontamination solution (HTH) used by the United States Navy.
Strong oxidizers may be used to detoxify warfare agent, however, several problems exist with the use of the strong oxidizers. The reactivity of most strong oxidizers inhibit long shelf life of any decontaminating solution, tend to be corrosive, and are hazardous to humans and the environment. One type of strong oxidizer is the peroxycarboxylic acids or “peracids” that do not possess most of the corrosive and hazardous characteristics, however, the peracids become unstable over short time periods, such as two or three months.
Bleaching agents are known in the detergent art for decolorization of stains. Bleaching agents irreversibly oxidize and decolorize bleachable soils present on fabrics. One type of bleaching agent contains peroxygen atoms, such as sodium perborate tetrahydrate (NaBO
4
.4H
2
O) and sodium perborate monohydrate (NaBO
4
.H
2
O). The peroxygen compounds contain two linked oxygen atoms (—O—O—), that provide an active, or free, oxygen when the link is broken. Peroxygen bleaches are known as being effective for stain and soil removal from fabrics. Detergent compositions also use bleaching agents to form peroxycarboxylic acids from bleaching activators. These detergent compositions generally contain approximately 0.03% bleaching agents and bleach activator during wash.
In view of the foregoing, there is a need for an effective chemical warfare agent decontamination solution which is noncorrosive, nontoxic, nonflammable, and environmentally safe. The present invention addresses this and other needs.
SUMMARY OF THE INVENTION
The present invention includes a method for decontaminating chemical and biological warfare agents comprising the steps of mixing a peroxygen compound with a bleach activator to generate a peroxycarboxylic acid in-situ and contacting a warfare agent with the generated in-situ peroxycarboxylic acid in an amount to effectively react with the warfare agent.
The present invention also includes a chemical and biological warfare agent decontaminating solution comprising a peroxygen compound and an effective amount of bleach activator, with the peroxygen compound and bleach activator mixed in a surfactant composition prior to contacting a warfare agent.
The present invention further includes an in-situ generated peroxycarboylic acid composition for decontaminating chemical and biological warfare agents formed from the process comprising the step of mixing a peroxygen compound with a bleach activator in a surfactant composition to generate the peroxycarboxylic acid in-situ prior to contacting a warfare agent.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention comprises an in-situ decontaminating solution for chemical and biological warfare applications. The decontaminating solution comprises a peroxycarboxylic acid generated from the mixing of a peroxygen compound with a bleach activator. The peroxycarboxylic acid is generated in-situ to overcome degradation of the decontaminating solution with time.
The decontaminating solution is applied onto a contaminated area or surface to neutralize or detoxify the chemical and/or biological warfare agent. Application of the decontamination solution includes placing the peroxygen compound or bleach activator in a surfactant composition, and mixing the peroxygen compound and bleach activator therein. The mixing of the peroxygen compound and bleach activator in the surfactant system generates a resultant peroxycarboxylic acid in-situ. The generated in-situ peroxycarboxylic acid is contacted with a warfare agent which reacts with the peroxycarboxylic acid and become detoxified. The solution is applied by mops, brushes, sprayers and other known solution applicators. The decontaminating solution of the present invention is noncorrosive, nontoxic, and nonflammable, and useful in rapidly neutralizing chemical and biological warfare agents, such as VX, GD and HD, and vegetative and endospore forming bacteria, fungi and virus.
Effective amounts of the peroxycarboxylic acid are determinable by those skilled in the art for specific concentrations of warfare agent, types and amounts of peroxygen and bleach activator components, contact methods, additional chemical warfare countermeasures, operational necessities, and other like factors considered for personnel ingress and egress from an exposed area. Preferably, effective detoxification includes normal human contact within a previously contaminated environment that has been treated with the decontamination solution of the present invention without any adverse health effects.
The peroxygen compound of the present invention includes any suitable peroxygen compound for reaction with a bleach activator to form an effective peroxycarboxylic acid for warfare agent neutralization. Preferred peroxygen compounds include, without limitation, percarbonates, perborates and other like compounds, with exemplary compounds including peracetate, perborate monohydrate, perborate tetrahydrate, monoperoxyphthalate, peroxymonosulfate, peroxydisulfate, percarbonate and hydrogen peroxide. Most preferably, hydrogen peroxide is used.
Hydrogen peroxide sources are well known in the art. They include the alkali metal peroxides, organic peroxide bleaching compounds such as urea peroxide, and inorganic persalt bleaching compounds, such as the alkali metal perborates, percarbonates, and perphosphates. Mixtures of two or more such peroxygen compounds also may be suitable for use within the scope of the present invention. Preferred compounds are sodium percarbonate, sodium perborate tetrahydrate and, especially, sodium perborate monohydrate. Sodium perborate monohydrate is preferred to tetrahydrate because it has excellent storage stability while also reacting quickly with bleach activators. This rapid reaction may form higher levels of percarboxylic acid which tend to enhance neutralization of warfare agents.
Typically, the molar ratio of hydrogen peroxide (or a peroxide compound generating the equivalent amount of H
2
O
2
) to bleach activator ranges from about 1.5:1 to about 4:1, preferably about 2:1 to about 4:1, most preferably from about 2.5:1 to about 3.5:1, such as 3:1. In such formulations the total amount of peroxygen compound, e.g., sodium perborate mono- or tetra-hydrate, may be present at a level within the range of from about 5% to about 50%, preferably from about 10% to about 25%, particularly from about
Bechtel, Esq. James B.
Griffin Steven P.
Nave Eileen E.
Pratt, Esq. Wyatt B.
The United States of America as represented by the Secretary of
LandOfFree
Chemical and biological warfare decontaminating solution... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Chemical and biological warfare decontaminating solution..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Chemical and biological warfare decontaminating solution... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2864164