COMPOSITION FOR REMOVING CHEMICAL RESIDUES, AND ITS USES

Abstract

The present invention relates to a composition for the removal of chemical residues, to a method for employing said composition, and also to the use of said composition for removing residues in materials, machines, and equipment contaminated with chemicals of any kind.

Description

COMPOSITION FOR REMOVING CHEMICAL RESIDUE, AND ITS USES FIELD OF INVENTION The present invention relates to a composition for the removal of chemical residues, to a method for employing said composition, and also to the use of said composition for removing residues in materials, machines, and equipment contaminated with chemicals of any kind. BACKGROUND OF THE INVENTION Currently, there is no effective solution in the industry for decontaminating materials, machinery, and / or equipment contaminated with chemical pollutants. In the event of an accident during maintenance or handling operations, splashes of liquids, solids, or gases can occur, resulting in contamination of the work area and / or protective equipment. Materials and surfaces in the work area are then contaminated by the chemical, even if it is not necessarily visible. This leads not only to risks of chemical injury for workers (through skin contact or inhalation) but also to risks of corrosion for materials and a consequent reduction in their lifespan. The use of an absorbent mineral, such as diatomaceous earth or sepiolite, or a specialty absorbent such as TRIVOREX® or UNISAFE PH PLUS® can neutralize splashes on floors. However, when the contaminated surface is not horizontal but vertical or uneven (walls, ceilings, machinery, and protective equipment), these absorbents cannot be used. None of the existing solutions available to technical experts are capable of effectively decontaminating such surfaces. Experts in the technique can: - Rinse the contaminated surface with water. All this action does is simply dilute the chemical, which requires the use of large volumes of water, thus generating a large volume of hazardous chemical waste. - Use a detergent such as soap and water, a surfactant and water, or a solvent such as acetone or ethane to remove hydrophobic products. Therefore, there is no neutralizing chemical activity and the surface is simply rinsed. - Use chemical decontaminants, but this has the disadvantage of being specific to one type of chemical and of being corrosive or irritating. Particular mention can be made of the product NEUTRAL®, composed of sodium hydroxide to neutralize acidic deoxidizing solutions, acidic solutions that can only remove basic solid residues, the base detergent (> IVIA / a / ZUZ l / UIU 14 / ρH 12) Mucasol® used to clean laboratory glassware, or the KolorSafe® decontaminant, an acid-specific decontaminant that is classified within the Carcinogenic-Mutagenic-Reprotoxic (CMR) category. - Use decontaminants in a military CBRN (nuclear, radiological, biological, chemical, and explosive) environment to decontaminate equipment contaminated with gases used in weapons or toxic substances, such as Ouvry's R2D2 / R2D4 DES'DEC® solution or Easydecon DF 200®. However, such decontaminants are sold only to the military and are ineffective for decontaminating corrosive chemicals, such as acids or bases, which are ubiquitous in industry. - Use a chemical decontaminant for materials: LeVert. This product neutralizes acids and bases. Acid and base neutralization means ensuring that the contaminated surface returns to a pH between 5.5 and 9, a pH at which acidity or alkalinity is not harmful to the body. However, this product has the disadvantage of leaving behind salts that can cause corrosion of certain surfaces or metals, such as raw steel. Furthermore, this product requires the use of an external means to monitor the pH and track the progress of the neutralization process (pH paper, pH meter). When fluorine-based compounds (such as hydrofluoric acid) are spilled or splashed in hard-to-reach areas, technicians face a major problem. This is because, in addition to eliminating the hazard related to the chemical's corrosiveness, protection against its toxicity is also necessary. Fluorine poisoning can occur after skin exposure, exposure through the gastrointestinal tract, and / or inhalation. This results in bone, respiratory, and cardiac disorders that can lead to death. The potentially lethal dose can be 5 mg / kg of body weight. None of the aforementioned solutions can reduce the toxicity of fluoride ions. A chemical decontaminant specifically for hydrofluoric acid and its derivatives is LeVert HF. This decontaminant removes contaminants from the surface of materials by restoring the pH of the contaminating chemical to between 5.5 and 9 and by binding fluorine ions. Decontamination is considered effective when the fluorine ion concentration reaches a threshold of 1.5 mg / L, at which point it becomes non-hazardous in the fluorochemical decontaminant mixture. Those skilled in the art should use external means (fluorine ion test strips, ion meter) to verify that this limit of 1.5 mg of fluorine ions per liter has been reached. However, the action of the chemical decontaminant LeVert HF is limited to hydrofluoric acid and other chemical compounds containing fluorine ions and therefore does not allow for the effective neutralization of base chemicals. Therefore, such compositions are not suitable. IVIA / a / ZUZ l / UIU 14 / universal utility and cannot indicate when the decontamination operation is complete. Furthermore, such compositions have a high concentration of NaCl, which corrodes metals. To date, and consequently, there is no composition that: (1) can decontaminate and neutralize chemicals of any kind, including 5-hydrofluoric acid and its derivatives through the binding of free fluorine ions, (2) does not require external means to indicate when the acid / base decontamination operation is complete, (3) is not hazardous to humans or the environment (non-toxic, non-corrosive, non-flammable and non-irritating), and 0 (4) be free of salts that could cause metal corrosion. However, the present inventors have had the distinction of finding a decontamination composition that presents an excellent compromise between these different criteria (1) to (4). 5 BRIEF DESCRIPTION OF THE INVENTION Thus, the invention relates to a decontamination composition comprising: - at least one primary neutralizing agent (a) that is an aluminum-20-ethylenediaminetetraacetic acid-based complex and has a pKa of > 4 - at least one secondary neutralizing agent (b) selected from an amphoteric agent, the two pKa values ​​of which meet the following conditions: (pKal + pKa2) / 2 > 5 7 > pKa > 4 > pKa2 > 7 And an agent that has at least a pKa of between 7 and 11, and mixtures thereof, - water, - optionally, a color indicator or a mixture of color indicators (c), and - optionally, at least one additive (d), characterized in that said composition is free of HaXb salts wherein H is an alkali metal or an alkaline earth metal, X is a halogen atom, a is an integer between 1 and 2, and b is an integer between 1 and 4. It also relates to a decontamination method that employs composition 35 of the present invention, characterized in that it comprises the following steps: (1) disperse the composition over the surface contaminated with a chemical, (2) repeat step (1) until a pH of between 5.5 and 9 is obtained, and (3) optionally rinse with water to prevent colored crystals from appearing during drying of the decontaminated surface. It also relates to the use of the composition according to the present invention to decontaminate materials, machines and equipment contaminated with chemicals of any kind. DETAILED DESCRIPTION OF THE INVENTION The invention relates to a decontamination composition comprising: - at least one primary neutralizing agent (a) that is an aluminum-based complex and ethylenediaminetetraacetic acid and that has a pKa of > 4 - at least one secondary neutralizing agent (b) selected from an amphoteric agent, the two pKa values ​​of which meet the following conditions: (pKal + pKa2) / 2 > 5 > pKal > 4 > pKa2 > 7 And an agent that has at least a pKa of between 7 and 11, and mixtures thereof, - water, - optionally, a color indicator or a mixture of color indicators (c), and - optionally, at least one additive (d), characterized in that said composition is free of HaXb salts wherein H is an alkali metal or an alkaline earth metal, X is a halogen atom, a is an integer between 1 and 2, and b is an integer between 1 and 4. The term HaXb salts refers not only to salts in molecular form, but also to particles composed of HaXb salts agglomerated to one another and not dissolved in the solution. This primary neutralizing agent can be the ANa2EDTAOH complex. The primary neutralizing agent may be present in an amount ranging from 0.1% to 25% by weight, preferably from 10% to 20% by weight, and most preferably from 15% to 18% by weight, in relation to the total weight of the composition. This secondary neutralizing agent can be selected from ascorbic acid and its salts, hydrogen carbonate and its salts, creatinine, glutathione, isoguanine, adenine, or a IVIA / a / ZUZ l / UIU 14 / amino acid and salts thereof, such as glutamic acid, aspartic acid, arginine, lysine, ornithine, cysteine ​​and mixtures thereof. Hydrogen carbonate and its salts can be sodium hydrogen carbonate, potassium hydrogen carbonate, ammonium hydrogen carbonate, and mixtures thereof. Glutamic acid and its salts can be glutamate in the form of sodium glutamate, sodium L-glutamate hydrate, and mixtures thereof. Salts of aspartic acid can be aspartate. Arginine salts can be L-arginine monohydrochloride. Ornithine salts can be L-ornithine monohydrochloride. Lysine salts can be L-lysine hydrochloride. In one specific modality, this secondary neutralizing agent is selected from sodium glutamate, lysine, niacin, cysteine, and L-arginine. This secondary neutralizing agent may be present in an amount ranging from 0.1% to 50% by weight, preferably from 1% to 20% by weight, and most preferably from 5% to 15% by weight, in relation to the total weight of the composition. Examples of additives that can be mentioned are dyes, fragrances, viscosity modifiers, and mixtures thereof. In a specific embodiment, said color indicator or said mixture of color indicators has a color change zone at a pH of between 1 and 7, preferably between 2 and 6, and more preferably between 2.5 and 5, and a color change zone at a pH of between 8 and 13, preferably between 8.5 and 11, and more preferably between 9 and 10. The color indicators that can be mentioned are methyl red, thymol blue, ethyl orange, methyl orange, tropaeolin OO, bromophenol blue and mixtures thereof. The color indicator may be present in an amount ranging from 0% to 5% by weight, preferably from 0.001% to 1% by weight, and most preferably from 0.002% to 0.5% by weight, in relation to the total weight of the composition. The composition of the present invention is free of HaXb salts, which means that it causes little or no corrosion or degradation of surfaces (plastic, metal, glass, etc.) on which it is applied and, specifically, of metallic surfaces, which corrode easily. Specifically, the composition of the present invention is free from at least one compound selected from NaCl salt, KCl salt, NaF salt, and NaBr salt. Advantageously, the composition of the invention comprises: (a) 5 to 25%, preferably 8 to 20%, and most preferably 10 to 17% of a primary neutralizing agent, IVIA / a / ZUZ l / UIU 14 / (b) from 1 to 50%, preferably from 5 to 15%, and more preferably from 8 to 13% of a secondary neutralizing agent, (c) from 0% to 5%, preferably from 0.001% to 1%, and more preferably from 0.002% to 0.5% of a color indicator or a mixture of color indicators, (d) water, these percentages being weight percentages related to the total weight of the composition. The present invention also relates to a decontamination method employing the composition of the present invention, characterized in that it comprises the following steps: (1) disperse the composition over a surface contaminated with a chemical, (2) repeat step (1) until a neutral pH is obtained, preferably a pH between 5.5 and 9, and (3) optionally rinse with water to prevent colored crystals from appearing during drying of the decontaminated surface. In the case where the composition includes a color indicator, step (1) is repeated until a neutral pH is visually obtained, preferably until a pH between 5.5 and 9 is obtained. The present invention also relates to the use of the composition of the present invention or as obtained by the method of the present invention for decontamination of materials, machines and equipment contaminated with chemicals of any kind. The term decontamination refers not only to the mechanical removal of the chemical contaminant, but also to its neutralization, that is: - restore the pH of the mixture of chemical contaminant and chemical decontaminant to between 5.5 and 9, and - Restore the level of free fluoride ions in the mixture of chemical contaminant and decontaminant to less than 1.5 mg / l when the chemical contaminant is hydrofluoric acid or derivatives thereof. The chemical contaminant can be a strong base or a strong acid, preferably sodium hydroxide, hydrochloric acid, hydrofluoric acid or derivatives thereof, such as ammonium fluoride or sodium fluoride, or mixtures thereof. The decontamination status can be monitored through the presence of a color indicator or a mixture of color indicators. Therefore, an external means of verifying acid / base decontamination may not be necessary. The composition according to the present invention can be used to decontaminate materials, machines and equipment contaminated with hydrofluoric acid and derivatives thereof, such as ammonium fluoride or sodium fluoride. EXAMPLES The following commercial products are used in the following examples: - L-glutamate sodium monohydrate sold by MB Biomedicals, LLC, - Methyl red sold by EMD Millipore Corporation, - thymol blue sold by Alfa Aesar, - L-arginine monohydrochloride sold by Alfa Esar, - L-lysine hydrochloride sold by ThermoFisher (Kandel) GmbH, - ethyl orange sold by Alfa Aesar, - bromophenol blue sold by EMD Millipore Corporation, - sodium hydroxide sold by VWR Chemicals, - sodium aluminate sold by Sigma Aldrich, - ethylenediaminetetraacetic acid (EDTA) sold by Merck Millipore. EXAMPLE 1 Decomposition composition 1 was prepared, which had the following content: IVIA / a / ZUZ l / UIU 14 / TABLE 1 Starting material Percentage by weight (%) Neutralizing agents Aluminum and EDTA complex with a pKa of 5.87 16.83 Sodium glutamate monohydrate 8.33 Color indicators Methyl red 0.00036 Thymol blue 0.0019 Solvent Water the remainder is composed of water Decontamination composition 1 is free of HaXb salts, as defined according to the present invention. Neutralization test A neutralization test was carried out with the following liquids: 1 M sodium hydroxide (NaOH) and 1 M hydrochloric acid (HCl), using the composition prepared in example 1 according to the following procedure: To 1 ml of 1 M sodium hydroxide (NaOH) or 1 ml of 1 M hydrochloric acid (HCl), the following was successfully added: mL, 2 mL, 3 mL, 4 mL, 5 mL, 10 mL, 20 mL, 30 mL, 40 mL and / or 50 mL of the solution from example 1, waiting a maximum of 1 minute between each addition, and the pH was measured after each addition. The results are shown in Table 2 and illustrated in Figure 1. TABLE 2 Volume of solution from example 1 added to 1 ml of 1 M NaOH (ml) pH Volume of solution from example 1 added to 1 ml of 1 M HCl (ml) pH 0 13.17 0 -0.18 1 12.81 1 3.8 2 9.81 2 5.58 3 9.48 3 6.01 4 9.28 4 6.24 5 9.12 5 6.4 10 8.63 10 6.83 20 8.17 20 7.14 30 7.94 30 7.25 40 7.85 40 7.3 50 7.78 50 7.34 Color test A color test was carried out with the following liquids: 1 M sodium hydroxide (NaOH) and 1 M hydrochloric acid (HCl), using the composition prepared in example 1 according to the following procedure: 10 ml of 1 M sodium hydroxide (NaOH) or 1 M hydrochloric acid (HCl) were added to a beaker containing 20 ml of the solution from Example 1. The color was observed with the naked eye. A color variation of the solution from Example 1 was observed as a function of pH. The results are presented in Table 3 below. TABLE 3 pH Color observed 3 Red 7 Yellow 12 Blue Fluoride ion binding test The fluoride ion binding test was carried out with 1 M ammonium fluoride (NH4F) solution, using the composition prepared in example 1 according to the following procedure: To 5 ml of 1 M ammonium fluoride (NH4F) solution, either 1 ml or 5 ml of the solution from Example 1 was successfully added, waiting a maximum of 1 minute between each addition, and the concentration of three free fluoride ions was continuously measured. The concentration of fluoride ions is measured with a PHM240 ion meter sold by Radiometer, and with an Orion™ brand electrode, specifically for fluoride ions, sold by Thermo Scientific. The results are shown in Figure 2. EXAMPLE 2 Decomposition composition 2 was prepared, which had the following content: TABLE 4 Starting material Percentage by weight (%) Neutralizing agents Aluminum and EDTA complex with a pKa of 5.87 16.04 L-Arginine monohydrochloride 12.86 Color indicator Thymol blue 0.004 Solvent Water the remainder is composed of water Decontamination composition 2 is free of HaXb salts, as defined according to the present invention. Neutralization test A neutralization test was carried out in accordance with the procedure in Example 1 using the composition in Example 2. The results are shown in Table 5 and illustrated in Figure 3. TABLE 5 Volume of solution from example 2 added to 1 ml of 1 M NaOH (ml) pH Volume of solution from example 2 added to 1 ml of 1 M HCl (ml) pH 0 13.52 0 0.25 1 9.58 1 2.48 2 9.03 2 3.65 3 8.78 3 5.12 4 8.65 4 5.56 5 8.52 5 5.78 10 8.19 10 6.31 15 8.02 20 6.68 20 7.9 30 6.84 30 7.76 40 6.89 40 7.67 50 6.95 50 7.59 Color test A color test was carried out according to the procedure in example 1 5 using the composition from example 2. A color variation of the solution from Example 2 was observed as a function of pH. The results are presented in Table 6 below. TABLE 6 pH Color observed 1 Red 7 Orange 12 Blue Fluoride ion binding test A fluorine ion bonding test was carried out according to the procedure in Example 1 using the composition in Example 2. The results are shown in Figure 4. EXAMPLE 3 Decomposition composition 3 was prepared, which had the following content: TABLE 7 Starting material Percentage by weight (%) Neutralizing agents Aluminum and EDTA complex with a pKa of 5.87 10.9 L-Lysine hydrochloride: 49.58 Color indicators Ethyl orange 0.002 Bromophenol blue 0.002 Solvent Water the remainder is composed of water Decontamination composition 3 is free of HaXb salts, as defined according to the present invention. IVIA / a / ZUZ l / UIU 14 / Neutralization test A neutralization test was carried out in accordance with the procedure in Example 1 using the composition in Example 3. The results are shown in Table 8 and illustrated in Figure 5. TABLE 8 Volume of solution from example 3 added to 1 ml of 1 M NaOH (ml) pH Volume of solution from example 3 added to 1 ml of 1 M HCl (ml) pH 0 13.26 0 -0.17 1 9.33 1 2.16 2 8.93 2 3.04 3 8.73 3 3.61 4 8.58 4 4.32 5 8.48 5 5.05 10 8.15 10 5.93 20 7.84 20 6.39 30 7.69 30 6.58 40 7.52 40 6.68 50 7.46 50 6.74 60 7.4 60 6.79 Color test A color test was performed according to the procedure in Example 1 using the composition from Example 3. A color variation of the solution from Example 3 was observed as a function of pH. The results are presented in Table 9 below. Color test A color test was carried out according to the procedure in example 1 using the composition in example 3. A color variation of the solution from Example 3 was observed as a function of pH. The results are presented in Table 9 below. TABLE 9 pH Color observed 3 Orange 7 Purple 12 Gray Fluoride ion binding test A fluorine ion bonding test was carried out according to the procedure in Example 1 using the composition in Example 3. The results are shown in Figure 6. In conclusion, decontamination compositions 1 to 3 neutralize 1 M sodium hydroxide and 1 M hydrochloric acid by restoring the pH to between 5.5 and 9. The variation in pH is accompanied by a change in color. Decontamination compositions 1 to 3 can also bind fluoride ions by restoring the concentration of free fluoride ions to an acceptable value, i.e., to a value less than 15 ± 1.5 mg / l.

Claims

1. A decontamination composition comprising: - at least one primary neutralizing agent (a) being an aluminum-based complex and ethylenediaminetetraacetic acid having a pKa of >g, - at least one secondary neutralizing agent (b) selected from an amphoteric agent, the two pKa values ​​of which satisfy the following conditions: (pKal + pKa2) / 2 > 5, 7 > pKal > 4, 11 > pKa2 > 7, and an agent having at least a pKa of between 7 and 11, and mixtures thereof, - water, - optionally a color indicator or a mixture of color indicators (c), and - optionally at least one additive (d), characterized in that said composition is free of HaXb salts, wherein H is an alkali metal or an alkaline earth metal, X is a halogen atom, a is an integer between 1 and 2, and b is an integer between 1 and 4.

2. The composition according to claim 1, further characterized in that said primary neutralizing agent is present in an amount ranging from 0.1% to 25% by weight, preferably from 10% to 20% by weight, and more preferably from 15% to 18% by weight, in relation to the total weight of the composition.

3. The composition according to claim 1 or 2, further characterized in that said secondary neutralizing agent is selected from ascorbic acid and salts thereof, hydrogen carbonate and salts thereof, creatinine, glutathione, isoguanine, adenine, an amino acid and salts thereof, such as glutamic acid, aspartic acid, arginine, lysine, ornithine, cysteine ​​and mixtures thereof.

4. The composition according to claim 3, further characterized in that said secondary neutralizing agent is selected from sodium glutamate, lysine, niacin, cysteine ​​and L-arginine.

5. The composition according to any of the preceding claims, further characterized in that said secondary neutralizing agent is present in an amount ranging from 0.1% to 50% by weight, preferably from 1% to 20% by weight, and more preferably from 5% to 15% by weight, in relation to the total weight of the composition.

6. The composition according to any of the preceding claims, further characterized in that said color indicator or said mixture of color indicators has a color change zone at a pH of between 1 and 7, preferably between 2 and 6, and more preferably between 2.5 and 5, and a color change zone at a pH of between 8 and 13, preferably between 8.5 and 11, and more preferably between 9 and 10. IVIA / a / ZUZ l / UIU 14 / 7. The composition according to claim 6, further characterized in that the color indicator is selected from methyl red, thymol blue, ethyl orange, methyl orange, tropaeolin 00, bromophenol blue, and mixtures thereof.

8. The composition according to claim 6 or 7, further characterized in that the color indicator or mixture of color indicators is present in an amount ranging from 0% to 5% by weight, preferably ranging from 0.001% to 1% by weight, and more preferably from 0.002% to 0.5% by weight, in relation to the total weight of the composition.

9. The composition according to any of the preceding claims, further characterized in that the HaXb salt is at least a compound selected from the NaCl salt, the KCl salt, the NaF salt, the NaBr salt.

10. The composition according to any of the preceding claims, further characterized in that the composition comprises: (a) 5 to 25%, preferably 8 to 20%, and more preferably 10 to 17% of a primary neutralizing agent, (b) 1 to 50%, preferably 5 to 15%, and more preferably 8 to 13% of a secondary neutralizing agent, (c) 0% to 5%, preferably 0.001% to 1%, and more preferably 0.002% to 0.5% of a color indicator or a mixture of color indicators, (d) water, said percentages being weight percentages relative to the total weight of the composition.

11. A decontamination method employing the composition of any of claims 1 to 10, characterized in that it comprises the following steps: (1) dispersing the composition onto a surface contaminated with a chemical, (2) repeating step (1) until a neutral pH is obtained, preferably until a pH between 5.5 and 9 is obtained, and (3) optionally rinsing with water to prevent colored crystals from appearing during drying of the decontaminated surface.

12. The decontamination method according to claim 11, further characterized in that said chemical is a corrosive product or is a chemical containing fluorine ions.

13. The use of the composition as claimed in any of claims 1 to 10 for decontaminating materials, machines and equipment contaminated with a chemical.

14. The use as claimed in claim 13, wherein said chemical is a corrosive product or is a chemical containing fluorine ions.