NO802157L - PREPARATIONS AND PROCEDURES FOR COMBATING DOMESTIC SUBSTANCES - Google Patents

Description

Dust in the home or "house dust" is the cause of a number of troublesome allergy symptoms for an unknown number of people who are constantly bothered by sneezing and a runny nose or by a sore throat and shortness of breath. In recent times, attention has been paid to the possible harmful effects that house dust can have. In recent times, the house-dust fauna, particularly anthropods, such as different types of mites either alive or dead, have been the subject of investigation in relation to house-dust atopy, a very important factor in the etiology of connection with bronchial asthma and rhinitis. The symptoms that occur with allergies due to house dust are usually the same as those found with perennial allergic rhinitis. sneezing, runny or stuffy nose and sore and watery eyes. These symptoms can be identical to those found in connection with hay fever.

There are no recommendations in the later literature with regard to the regulation of house dust mites. Neither chemical nor hygienic measures seem to be possible due to a lack of knowledge in the area. Furthermore, it has been possible to demonstrate that most mites are only slightly affected by concentrations below one percent, and this will in most cases be too strong a treatment for them to be used indoors, i.e. places where you can expect high density of mites such as in upholstered chairs, mattresses etc. Furthermore, such types of treatment will not affect waste and dead mites, which are known as a source of allergens.

It is therefore a purpose of the present invention to combat the allergens found in house dust.

Furthermore, it is a purpose of the present invention to provide a composition for combating allergens found in substances, and where this composition is very well suited for use in connection with humans.

Furthermore, it is a purpose of the invention to combat waste from mites found in substances.

Furthermore, it is a purpose of the invention to be able to treat substances in such a way as to limit the movement of said mites and their waste, in addition to maintaining low humidity in the area around the mites and isolating them^

from critical nutrients.

Furthermore, it is a purpose of the invention to apply a composition for combating allergens found in substances, and where this is done in such a way that one regulates the speed of application and the evenness of said application, so that the substance can be completely covered and yet will be dry within a reasonable period of time.

These other purposes of the invention will be apparent from the following description and claims.

The connection between mites, allergies and house dust now seems to suggest that alleviation of allergies can be achieved in a typical household environment by changing the microenvironment of said mites in the specific areas of the house that will be of great importance when it comes to combating the mites Activity. Furthermore, a change to the mites' microenvironment can be achieved in such a way that it is compatible with human activity.

It is well known that certain areas in a typical house which are characterized by the dominance of different substances such as upholstered furniture, mattresses and different types of wallpaper, are ideal environments for different types of mites. It has now been found that if these substances are periodically treated with a composition that has certain physical and chemical properties, then the mites' activity on and in these substances can be combated with a corresponding reduction in the substance's allergenic ability. It has also been found that the shape of the composition is important for combating said mites, in particular a control of the speed of application, the evenness of the application and the drying time. In order to achieve this, it has further been found that an aerosol spray of specific ingredients is very effective in reducing the activity of said mites, and in combating waste from them.

Control of the mites' activity includes a control of both biological and physical activities of the aforementioned mites and their waste, and where the latter includes chitinous skeletons and excrement.

It has been found that combating the activity of the mites can best be achieved by changing the microenvironment in certain substances where a high density of mites is traditionally found, and where this can be done by a coating composition that tends to isolate the mites and/or their dead skeletons and excrement. It has also been found that this type of control significantly reduces allergic reactions. Furthermore, it has been found that if a suitable substance is chosen to isolate mites and their waste, certain critical environmental factors such as humidity level and nutrient availability can also be changed, and this will further regulate the mites' activity.

Food sources for mites include skin debris, dander, dust fibers and food particles. Isolation of mites from these critical foodstuffs is achieved by coating certain substances found in the household environment where mites tend to live and reproduce. This coating will then form a barrier on the fabric between the mites present and important nutrients that tend to accumulate on these fabrics after treatment.

Optimal substances for regulating mite activity thus include coating compositions which:-(a) limit the mobility of mites and mite waste, (b) maintain reduced humidity around the mites, and

(c) Isolates and/or prevents the mites from critical

nutrients, but (d) must not alter the physicality of the host substrate,

and

(e) must only interrupt normal use of the host substrate for a limited period of time.

It should be obvious that the environment where a mite is found is usually dusty surfaces of the type found in every home. A treatment of these surfaces will thus be the most effective means of combating the mite's activity.

Compositions according to the present invention which are suitable for combating allergens in substances thus include a coating oil-and-water emulsion containing the following: - (a) a hydrophobic solvent with a flash point between 177 and 260°C,

(b) an emulsifier,

(c) a propellant, and

(d) water.

The coatings obtained from pressurized compositions will be hydrophobic, generally essentially continuous, and will limit the mobility of the mites and the mite waste, while at the same time changing the mites' microenvironment by forming a barrier, around the mites and the nutrients and the water.

It has been found that repeated applications of these coatings on certain substances in a normal household environment significantly reduce the activity of the mites and this gives a corresponding reduction in the allergy potential of these substances.

Limiting the movement of mites and the mite waste.

Coating compositions of the present invention are effective only as long as dust mites and their waste are immobilized and the mites are maintained under less than optimal growth conditions. It is thus critical according to the present invention that the applied coating should be hydrophobic. This means that the coating itself must not attract moisture that could facilitate the growth of new mite colonies.

The connection between mites and house dust allergy is well known. What is not known, however, is the relationship between said mites and the allergic factors. There are three systems by which products from mites are assumed to be deposited on house dust and in each of these systems the waste will be easily mobile and in itself will tend to be dispersed in the air as part of the dust fibres. These systems are the following:-(1) the integument system contributes to a casting of the surface skin of the mites, various fluids secreted in connection with their prey, as well as glands and their secretions;

(2) the reproductive system provides eggs, fluids in connection with the transfer of gametes and any other substances in connection with egg laying and copulation; and ..-r

'in

(3) the digestive system itself produces excrement with a variety of different components, and an intestinal lining that is very similar to a peritrophic membrane.

It thus appears that combating these types of mite waste is achieved according to the present invention by applying an emulsion composition which provides a quick-drying coating which essentially moistens the mites and their waste and attaches them to it. substance in which they live. Furthermore, the coating according to the present invention must be flexible in order for it to maintain its continuity, and be able to capture the waste when the material is bent. The net effect of treating substances infested with mites and waste with coating compositions according to the present invention is to reduce the number of living mites in the substance. Secondarily, these coated fabrics will generally be essentially impermeable to mites that would possibly try to reinfect the fabric, and thus the fabric surface will no longer be an ideal microenvironment for mite activity, and the mites will thus seek other types of environments and thereby reduce the allergy potential of the treated fabric.

Maintenance of reduced humidity in the microenvironment Population growth for mites is very closely linked to the absolute humidity in the air both indoors and outdoors, and any change in humidity is followed by a change in

the number of mites and the mites' activity.

It was determined that standardized handy North American house dust mites have a constant equilibrium water mass that is independent of the surrounding water vapor activity when this is above the critical equilibrium activity (CEA = .70 at 25°C.). In the case of water vapor activities under the mentioned CEA, the transpiration rate will be greater than the absorption rate and there will be a net loss of water for a certain period of time.

Furthermore, it has been established that the rate of said water vapor for mites kept in dehydrated conditions is inversely proportional to the water vapor activity in the air.

For sample water vapor activities of .525", 225 and .00, for example, the water loss rate will respectively be 1.11, l. kO and 1.77$ ti<~mer at 25°C. Mean survival times for these dehydrating activities are 6°-> 55 and 43 hours, respectively. Stan-. dardized dogs contain 81 percent water by weight and can tolerate a water loss of up to 46.5 percent before death occurs.

Thus, substances with a high mite density can be coated with the help of compositions according to the present invention and in this way effectively regulate the microenvironment of the mites and subsequently reduce the mite populations. This control is partly achieved by the fact that the continuous flexible films applied to the fabric are hydrophobic in nature. Said coating produces films which, when air-dried, have a very low water tension. These films tend to keep the moisture level below that required to maintain the activity of the mites, ie a CEA of less than 0.7 at 25°C. This results in an environment that is susceptible to mite activity.

Isolation of mites from critical nutrients House dust mites prefer nutrients such as human skin waste, dander, dry hair, vegetable fibers such as lint, yeast and gelatin. Substances where mites tend to gather can be coated with compositions that limit their availability with the help of the present invention

of such nutrients to the mites. As the coating in itself is not a nutrient for mites, a continuous coating will tend to combat the mites' activity due to starving them.

Application of the coating

It has been established that arthropods such as mites have a peak growth period that occurs annually depending on the climate. In temperate humid climates, the peak growth period for these types of mites will thus be from July to October. In addition to this, it has been observed that there is a high correlation between maximum indoor humidity and live mites that are present during the peak growth period...

Mån has further found that if certain optimal mite host substances are found in the household and these are treated with compositions according to the present invention before such a period, then the mite population and mite waste will be substantially reduced and the allergy potential of these substances correspondingly reduced. Thus, certain critical substances in a household environment have been selectively treated before and during the peak growth period in order to combat the activity of the mites and to avoid re-infection by the mites, thereby reducing the allergy potential of the treated substance.

There are certain areas in a typical household environment that are more favorable for mite activity than others. This includes mattresses, all types of bed mats, upholstered furniture and wallpaper.

The high mite populations usually found in mattresses are partly due to an excess of human skin waste as well as the plant fibers present in the mattresses. In addition, you will find optimal and constant moisture conditions in the mattress. It has thus been found that the mites live in the surface layer of the mattress. It is therefore clear that mattresses will be a reservoir for the activity of mites in most household environments, and will thus be a source for re-infestation of mites throughout the house. A preferred area for treatment according to the present invention will thus be the entire mattress surface or other bed base. This treatment will preferably be carried out periodically throughout the year.

The composition of the coating

The present invention combats allergens by periodically coating certain substances with a stable emulsion that includes water, a hydrophobic hydrocarbon solvent with a high flash point as well as an emulsifying agent and a propellant. Said stable emulsion is then packaged in an aerosol type container having a valve and a release button.

For the present purpose, a stable emulsion will be defined as a water-in-oil or oil-in-water emulsion where the dispersed phase essentially remains colloidally dispersed and does not separate into a separate continuous liquid phase. This emulsion is considered stable if a

'in

such separation does not occur within 71 hours after emulsification,

It is critical for the present purpose that the coating applied to the substrate is in the form of a stable emulsion, because this effectively treats the allergens present in the various substrates in the form of a film of the hydrophobic repellant. When, for example, the hydrophobic control agent is applied as such without emulsification, in certain cases it has been found that it very difficult to moisten the allergens. Another problem that arises from time to time is that the work substrate is not completely covered, and you will thus find points where there is a lot of mite activity after the treatment.

The concentration of the hydrophobic control agent varies from approx. 1 to approx. 5% by weight of the substrate when this is a substance. Generally, it has been observed that concentrations below 0.5% by weight of the hydrophobic agent are not effective, while coatings above 5% by weight usually do not increase the degree of protection.

The hydrophobic repellant

Hydrophobic control agents suitable for the present purpose are organic liquids consisting of carbon and hydrogen, and having a flash point between 177 and 260°C. These liquid hydrophobic repellants have a wide viscosity range and include:-

(a) liquids such as white mineral oils and paraffin oils which are polycyclic, high-boiling fractions with a flash point between 205 and 245°C, and which have been decoloured, as well as natural oils such as rhisines oil, groundnut oil, linseed oil and mixtures of these; (b) mixtures of liquids of the type described above with semi-solids, such as petroleum, lanolin, glycols and mixtures thereof;

(c) mixtures of liquids and solids such as

'in

paraffinic and isoparaffinic waxes and mixtures thereof; and

(d) mixtures of the substances mentioned under (a)

and (c) above.

It should be obvious that it is very important

viscosity of the pesticide used to control mites and their waste, as well as the moisture level. at a suitable level, as well as limiting the availability of nutrients..

These stable emulsion coating compositions are applied to the entire fabric surface and should preferably moisten, bind and/or react with said mites and their waste, so that when the water evaporates, you will essentially get a continuous coating that limits the mites' mobility and the same applies their waste, and changes their microenvironment, so that they receive limited water and nutrient supply.

Emulsifiers

As mentioned above, it is critical for the present purpose that the coatings applied to the substrate are in the form of a liquid with a low surface tension in order to be able to wet the material with the film-forming solution. In order to achieve the desired surface tension, it has been found necessary to add small amounts of emulsifiers to the coating compositions. These emulsifiers can be either anionic or nonionic. Useful emulsifiers include fluorocarbon surfactants, salts of aliphatic sulfates, alkylaryl polyethylene oxides and other commonly used anionic emulsifiers.

These emulsifiers are used to disperse the hydrophobic control agent in water whereby a stable oil-in-water emulsion (o/w) is formed or to disperse the water in the hydrophobic control agent whereby a stable water-in-oil emulsion is formed (w /o). These emulsions are of such a type that they are stable and when applied to a substrate, the hydrophobic control agent will form an essentially continuous film on the mites. Concentration and type of the emulsifying agent1 used is determined by the type of emulsion that is desired and/or the concentration of the hydrophobic control agent used.

The fuel

It is critical for the present purpose that the film-forming solution can be applied to the substance in a regulated manner, and that the applied solution is essentially dry within a reasonable period of time after application. It has been found that the solution does not need to penetrate deeply into certain substances, for example of the type found in upholstered furniture, mattresses etc., to be effective in combating mites. The opposite may in fact be the case, as over-moistening of the substance can have harmful effects such as prolonged drying time, which reduces the solution's ability to immobilize the mites. In addition, the actual materiality of the treated material can also change due to possible overmoistening. Because of this, it has been found that the method of application is very important in order to achieve the full effect of the present invention. According to the present invention, the film-forming solution will thus be applied by an aerosol propellant which is under pressure.

The preferred propellants are liquid normally gaseous hydrocarbons, liquid halogenated hydrocarbons and inert compressible gases. Preferred hydrocarbon propellants include saturated aliphatic hydrocarbons such as propane, butane, isobutane, n-pentane and isopentane. Preferred halogenated hydrocarbons include dichlorodifluoroethane, dichlorotetrafluoroethane, trichlorotrifluoroethane and difluoromethane. Preferred inert compressible gases that can be used as propellants include nitrous oxide, nitrogen and carbon dioxide. You can also use a mixture of two or more propellants. Other usable propellants include normal and branched hexanes and heptanes.

The propellant is preferably used in an amount sufficient to expel the entire contents of the container. Usually, the propellant will amount to from 5 to approx. 50 percent, preferably from approx. 5 to approx. 20 percent by weight of the total ■ • composition. The compounds will usually be expelled from the container in the form of a foam or a wet surface shower. The pressure in the container will usually be from approx. 0.35 to 5.27 kg/cm^ above atmospheric pressure.

Examples I to IV

- The following examples are given to illustrate the present invention. It is understood that these examples are only illustrative and that the invention as such is not limited to the examples mentioned.

Different coating compositions under pressure are described for application to different types of fabrics. Said coating will quickly dry to films that are hydrophobic. It will be clear from the following examples that different types of coating can be applied to a number of different substances in order to thereby achieve a fight against the mites' activity and thereby reduce the substance's allergy potential. It is also clear from the examples that a system for mite control can be developed in a typical household environment. Such a system will require periodic treatment of certain fabric surfaces, while other types of fabric can be treated with a lower frequency.

It is expected that if these treatments are carried out on all critical substances in a household environment, then the activity of the mites can be significantly reduced and together with this the allergy potential of the environment can also be reduced.

The examples were carried out using techniques known in emulsion technology. The application of these aerosols to the fabric surfaces is indicated in grams per m^.

Claims (9)

1. Manufactured article which is suitable for combating allergens in substances, characterized by including a container which is under pressure and containing: (l) a propellant, (2) a hydrophobic organic solvent with a flash point between 177 and 260°C, (3) water, and (4) .. an emulsifying agent1. 2. Article according to claim 1, characterized in that said solvent and said water constitute a water-in-oil emulsion. 3« Article according to claim 1, characterized in that said solvent and water constitute an oil-in-water emulsion. 4. Method for combating allergens in substances, characterized by spraying said substance with from 1 to 5 percent by weight of the substance, with an aqueous coating composition that is under pressure and which is essential in combating said allergens, and where said composition includes an emulsion containing: (1) an aerosol propellant, (2) a hydrophobic organic solvent with a flash point between 177 and 260°C, (3) water, and (4) an emulsifier. 5. Method according to claim 6, characterized in that said emulsion is a water-in-oil emulsion. 6. Method according to claim 6, characterized in that said emulsion is an oil-in-water emulsion. 7. Procedure for regulating the biological and physical activity of mites, including by limiting the mobility of said mites and limiting the availability of critical nutrients for said mites, while maintaining an environment with reduced humidity around said mites, characterized by that you spray substances containing said mites with a watery shower under pressure and deposit on said substance from between 1 to approx. 5 percent by weight of an emulsion containing a hydrophobic organic solvent with a flash point of between 177 and 26o°C., and where said organic solvent is essential for combating said mite. 8. Method according to claim 7> characterized in that said emulsion is a water-in-oil emulsion. 9. Method according to claim 7> characterized in that said emulsion is an oil-in-water emulsion.