Patent Application
20110071334
The present invention relates to the decontamination of surfaces or the destruction of explosives liable to contain chemical or bacteriological toxic agents, in particular organophosphorus or organosulfur toxic agents and/or pollutants, especially in the field of chemical warfare agents or in the field of agriculture, for example for the decontamination of insecticides.
Many organophosphorus esters derived from phosphoric and phosphonic acids currently exist, which are used as chemical warfare agents or toxic warfare agents, such as the toxic agents or products G: “Tabun”, “Sarin” or “Soman”, or as insecticides in agriculture, for instance “paraoxon”, “diazinon” or the toxic agent VX.
These compounds have high neurotoxicity due to their phosphorylating power on cholinesterases, inhibition of which leads to death by accumulation of acetylcholine in the body.
Moreover, organosulfur toxic products also exist, such as industrial sulfides or warfare agents of the vesicant family, such as yperite (or toxic agent HD).
The existence of large stocks of warfare munitions liable to contain chemical or bacteriological toxic agents and the increasing threat of terrorist actions using explosive or dispersant systems containing such toxic agents have been the impetus for studies into effective solutions for decontamination and/or destruction.
As a general rule, the decontamination of toxic or bacteriological agents is performed by reduction, oxidation or hydrolysis.
Several types of decontaminating composition exist. Examples that may be mentioned include alkaline solutions, such as solutions of sodium hydroxide, of alkanolamines or of amines or hypochlorite solutions. These solutions have the drawback of being very corrosive toward the contaminated materials.
Other compositions containing an organic or mineral peroxidizing agent, such as a peracid or a peroxide, have been recommended, optionally in combination with a surfactant of quaternary ammonium type (FR 2 651 133 and FR 2 676 368), a sequestrant (FR 2 766 725) or a surfactant formed from an amine oxide (FR 2 766 724).
Decontaminating compositions have also been described containing chlorinated derivatives such as chloroisocyanurates (WO 00/51687 and DE 1 005 899); biocides including quaternary ammonium derivatives in combination with enzymes (WO 01/0056380) or metal hydroxide and oxide nanoparticles, especially of alkali metals, alkaline-earth metals and transition metals (U.S. Pat. No. 6,827,766).
It has been proposed to add a foaming agent to these decontaminating compositions (U.S. Pat. No. 6,376,436 and U.S. Pat. No. 2,392,936).
In many cases, it is highly desirable to make the explosive or dispersant system explode on site using a detonator or a countercharge.
In order to limit the effects of the blast of the explosion, it has already been proposed to use a foam that is capable of absorbing the pressure generated by the shock wave of the explosion (WO 94/00198). Usually, when the explosive cannot be transported, it is confined in a mobile chamber (WO 98/56465), for instance a Kevlar® tent whose inner space is entirely filled with a foam obtained in situ by diffusing a gas stream in an aqueous solution of a composition containing a foaming agent, such as a surfactant (WO 94/00198).
These foaming compositions are generally formulated based on anionic surfactants. Specifically, these anionic surfactants make it possible to obtain high swelling coefficients, excellent stability and viscoelastic behavior of the foam that are favorable to absorption of the energy of the explosion blast.
It is desirable to have available foaming compositions that are also decontaminating so as to be able simultaneously to destroy the explosive and to decontaminate the toxic agents that it is liable to contain.
Given the nature of the chemical reactions involved, for decontaminating chemical toxic agents (oxidation or nucleophilic substitution), decontaminating agents are generally used in the presence of cationic surfactants. Toxic agents are decomposed by means of a micellar catalysis reaction via microemulsions of the decontaminating agents that form in the presence of the cationic surfactant. Furthermore, the combination of cationic surfactants and of peracids has a very broad spectrum of decontaminating efficacy on biological agents (bacteria, viruses, spores and toxins).
Unfortunately, the cationic surfactants that have a high critical micellar concentration are not themselves very good foaming agents. Furthermore, their presence in foaming compositions comprising anionic surfactants leads to the formation of an electrically neutral hydrophobic complex that is very sparingly soluble in aqueous media and to destabilization of the foam.
The Applicant has now found a novel decontaminating solution free of cationic surfactants that can simultaneously reduce the blast effect of an explosive device and decontaminate the toxic and/or bacteriological agents contained therein.
Thus, the present invention relates to a foaming decontaminating aqueous solution comprising, by weight relative to the total weight of the composition:
The invention also relates to the composition for preparing the foaming decontaminating aqueous solution of the invention.
This composition contains all the constituents necessary for preparing the aqueous solution according to the invention, and optionally all or some of the water.
Preferably, in the composition for preparing the foaming decontaminating aqueous solution of the invention, the peroxidizing agent, and optionally its stabilizing agent, are separate from the other constituents.
Thus, preferably, said composition comprises in separate packagings I and II:
Preferably, packaging II contains the constituents other than the peroxidizing agent and its stabilizer in the form of a concentrated solution, the concentration limit being the solubility limit of the constituents contained in packaging II.
Advantageously, packaging II is free of water or contains only the amount of water necessary to form a concentrated solution of the other constituents. The amount of water to be added may be readily determined by a person skilled in the art, as a function of the solubility of the other constituents.
The organic or mineral water-soluble peroxidizing agent is chosen from:
As examples of water-soluble peroxidizing agents that are preferred for the purposes of the invention, mention may be made especially of:
The anionic surfactant may be chosen from the anionic agents below:
R—C(═O)—O—R′—SO3—X and R—C(═O)—O—R′—SO4—X
R—O—R′—SO3—X
The above anionic surfactants are commercially available anionic agents or may be prepared via standard processes that are well known to those skilled in the art. By way of reference concerning these anionic surfactants, mention will be made of the publications below:
Preferably, an anionic surfactant that allows a reduction in the surface tension of water at 20° C. of at least 4.0×10−2 N/m will be chosen.
The foaming power of the composition according to the invention is determined according to standard NF T 73404, also known as the Ross-Miles test.
The composition may contain from 0 to 10% and preferably 0.5% to 4% of an amphoteric surfactant such as (C8-C18)alkylbetaines, (C8-C18)alkylsulfobetaines and (C8-C18)alkylamphocarboxyglycinates or (C8-C18)alkylamphocarboxypropionates or mixtures thereof.
The amine oxide used in the foaming decontaminating composition according to the invention is any amine oxide that is capable of effecting micellar catalysis within the composition. The oxidation and nucleophilic substitution reactions are thus favored by increasing the surface for exchange between the foaming decontaminating composition of the invention and the toxic agent.
The function of the amine oxide within the composition according to the invention is entirely different to the stabilizing function described in GB 1 089 997.
It has been found that the use of an amine oxide as micellar catalyst instead of a cationic surfactant does not reduce, but, on the contrary, considerably reinforces the foaming power of the decontaminating composition.
Advantageously, the amine oxide will be chosen from:
in which:
The above amine oxides are commercially available amine oxides or may be obtained via standard processes that are well known to those skilled in the art, for example by oxidation reaction of tertiary amines with peroxidizing agents, for example hydrogen peroxide.
Examples of amine oxides that correspond to one or other of the above formulae are:
Any alkaline buffer capable of adjusting the pH of the composition of the invention to between 7 and 11 and preferably between 8.0 and 9.5 may be used. The alkaline buffer is preferably chosen from alkali metal or alkaline-earth metal carbonates, bicarbonates, borates, silicates, citrates, tartrates and phosphates, or mixtures thereof.
Sodium or potassium carbonate, borate, phosphate (ortho-, pyro- or tripolyphosphate) or citrate buffers are particularly preferred, in particular the carbonates.
Furthermore, the composition of the invention may optionally comprise one or more stabilizers for the peroxidizing agent, such as:
Optionally, the aqueous solution according to the invention may also comprise a nonionic surfactant of the family of fatty alcohols and ethoxylated fatty alcohols, ethoxylated-propoxylated fatty alcohols, fatty amides, ethoxylated fatty amides, especially diethanolamides, alkylpolyglucosides, etc.
The aqueous solution according to the invention may also comprise viscosity regulators, such as xanthan, carrageenan, gellan or guar gums, Laponite® (colloidal clay: Mg, Na and Li silicate), carboxymethylcellulose, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, modified starch, polyethylene glycol, polyacrylic acid and polyacrylates (carbomers), etc., preferably with a molecular mass of between 400 and 400 000 daltons.
Finally, the aqueous solution according to the invention may, still optionally, contain alcoholic or glycolic solvents, polyglycols, glycol ethers, hydrotropic agents (urea, ethoxylated phenol containing 3-6 mol of ethylene oxide, and alkali metal or ammonium cumenesulfonates, toluenesulfonates or xylenesulfonates).
The aqueous solutions according to the invention are obtained by extemporaneous addition of the peroxidizing agent to the aqueous solution containing the other constituents.
The invention also relates to the process for decontaminating surfaces, which consists in:
The invention also relates to the process for destroying explosives liable to contain chemical or bacteriological toxic agents, which consists in:
The decontaminating efficacy and the foaming power of the aqueous solutions according to the invention on toxic warfare agents was evaluated on analogs of toxic agents, namely analogs of yperite, VX and the G products.
These analogs of toxic agents are molecules with a lower degree of toxicity, but a chemical structure and reactivity demonstrated as being equivalent to that of the actual toxic agents.
This product proposed as analog is chloroethyl phenylethyl sulfide (to be compared with yperite: ClCH2CH2SCH2CH2Cl), and characterized by:
Like yperite, it is generally destroyed by oxidation; the sulfur atom is oxidized to chlorosulfoxide and then to chlorosulfone; the vinyl sulfone forms in alkaline medium according to the reaction scheme below, in which R=phenylethyl:
The reaction is monitored by gas/mass chromatography and thin-layer chromatography.
This product, like its para-fluoro homolog, is a good analog of VX: CH3CH2—O—P(O)(CH3)—S—CH2CH2—N(iPr)2, especially due to the presence of the β-aminothiol function. Specifically, the oxidation should take place on the sulfur and avoid the formation of an N-oxide (highly toxic).
Like VX, it is destroyed in alkaline medium or in the presence of an oxidizing acid, giving either a disulfide or a sulfonic acid.
The reaction is monitored over time by TLC (revelation with iodine).
Commercial insecticide; excellent analog of G products:
These products are generally destroyed via a nucleophilic substitution reaction of the fluorine (Sarin, Soman) or of the cyano group (Tabun)
The reaction is monitored:
The invention will now be described in greater detail by the illustrative but non-limiting examples below.
The peroxidizing agent was mixed with the other constituents and water in a container, to obtain the aqueous solution below:
The pH of the solution was 8.2.
The peroxidizing agent was mixed with the other constituents and water in a container, to obtain the aqueous solution below:
The pH of the solution was 9.
The peroxidizing agent was mixed with the other constituents and water in a container, to obtain the aqueous solution below:
The pH of the solution was 8.5.
In these tests, the aqueous solutions according to the invention described in Examples 1 to 3 were compared with the standard decontaminating composition A below, to which was added the foaming composition B.
5 g of the foaming decontaminating aqueous solution of the invention were deposited using a pipette onto a glass plate coated with HD or VX analogs in a Sovirel flask.
The Sovirel flask was stirred for 20 minutes and the oxidation reaction was then quenched with 2 ml of thiosulfate.
Extraction was then performed (of the analog and its metabolites remaining on the plate) with an ethyl acetate/cyclohexane mixture (50/50).
Analysis of the residual chemical agent (analog+metabolites) was performed by GC (Silicone SE column) and by thin-layer chromatography.
5 g of the foaming decontaminating aqueous solution were deposited on the G product analog in a Sovirel flask.
The Sovirel flask was then placed on a shaker plate with maximum agitation for 20 minutes.
The following were then introduced into the Sovirel flask:
The Sovirel flask was stoppered once again and shaken manually for 10 seconds. The supernatant organic phase was recovered immediately in another 25 ml Sovirel flask containing sodium sulfate and injected in GC onto an OV1 glass column.
The results obtained are given in the Table I below:
| Number | Date | Country | Kind |
|---|---|---|---|
| 0853437 | May 2008 | FR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/FR2009/050973 | 5/26/2009 | WO | 00 | 11/24/2010 |
