EP2176198B1

EP2176198B1 - Improved incapacitant spray

Info

Publication number: EP2176198B1
Application number: EP08776178A
Authority: EP
Inventors: Wayne Morris
Original assignee: Bauer Eran
Current assignee: Bauer Eran; BAUER, GERARD
Priority date: 2007-07-05
Filing date: 2008-07-07
Publication date: 2012-06-27
Anticipated expiration: 2028-07-07
Also published as: EP2176198B8; WO2009004390A3; EP2176198A2; GB0812372D0; WO2009004390A2; GB2453013A; GB0713011D0; GB2453013B

Abstract

An incapacitant mixture which induces temporary blindness in a human or animal comprises pelargonyl vanillylamide and a carrier. The carrier is miscible with water and has a boiling point greater than that of water. PAVA is the primary incapacitant in the mixture and the proportion of PAVA in the mixture is 0.65 per cent or less.

Description

Field of the Invention

This invention relates to incapacitants, and in particular to incapacitant sprays used in law enforcement.

Background to the Invention

Incapacitants containing pelargonyl vanillylamide (PAVA) as the primary incapacitant are known from GB2337806 and WO 2006/055640 . Such incapacitants have been developed using carriers comprising mixtures of alcohol and water to solubilise the PAVA. These incapacitants function by inducing temporary blindness when the mixture enters the eyes without causing injury to the skin or mucous membranes of an individual. Whilst some tears may be produced as a side effect of the incapacitant entering the eyes, it is not the production of tears which causes temporary blindness. Blindness results from intense pain in the eyes which causes the eyelids to close involuntarily rendering the person blind until such time as the effect of the incapacitant wears off.
Such incapacitant mixtures have an evaporation rate greater than that of water. When an incapacitant spray is used it is inevitable that some overspray will occur. When the solvent evaporates, neat PAVA is left behind and this causes problems with cross contamination.
It has also been shown that such incapacitant mixtures are susceptible to freezing at temperatures below 2°C. Incapacitant sprays using this mixture are therefore of limited use in cold weather or in countries with a cold climate.
It has also been shown that in windy conditions such incapacitant mixtures can break up into small, sub-micron size droplets. Sub-micron size droplets are more likely to cross the skin or enter the lungs.
It has also been shown that such incapacitant mixtures can break up into small, sub-micron size droplets on impact which can rebound from the person being sprayed. This can be a problem for bystanders in confined spaces such as custody suites or inside vehicles.
It would therefore be desirable to provide an improved incapacitant for use by police forces, peace-keeping forces, the military and also for personal use.

Summary of the Invention

The invention provides a liquid phase incapacitant mixture comprising pelargonic acid vannillylamide (PAVA) and a carrier, wherein the mixture induces temporary blindness and/or irritation in the mucus membranes in a human or animal, wherein the carrier is miscible with water and has a boiling point greater than that of water, and includes a water-miscible solvent selected from the group comprising glycerine and glycols in a proportion of 50 per cent or more by weight of the mixture and the carrier further comprises water and an alcohol, and wherein PAVA is the primary incapacitant in the mixture, the proportion of PAVA in the mixture being 0.65 per cent or less by weight.
The term PAVA, used throughout the specification, refers to pelargonic acid vannillylamide classified under CAS No. 2444-46-4.
Preferably, the proportion of PAVA is between 0.3 and 0.65 per cent by weight. More preferably, the proportion of PAVA is between 0.3 and 0.6 per cent by weight.
Preferably the proportion of the glycol or glycerine in the mixture is 60 per cent or more by weight. More preferably the proportion of glycol or glycerine in the mixture is 72 per cent by weight. Suitable glycols include any edible glycols from the glycol family, for example ethylene glycol or propylene glycol.
Preferably the water-miscible solvent is propylene glycol. Preferably the proportion of propylene glycol in the mixture is 50 per cent or more by weight. More preferably the proportion of propylene glycol in the mixture is 60 per cent or more by weight. More preferably the proportion of propylene glycol is between 65 and 90 per cent. Still more preferably, the proportion of propylene glycol is between 65 and 80 per cent by weight. Still more preferably, the proportion of propylene glycol is 72 per cent by weight.
Preferably the proportion of water in the mixture 30 per cent or less by weight. More preferably, the proportion of water is between 20 and 30 per cent by weight. Still more preferably, the proportion of water in the mixture is 25 per cent by weight.
Any suitable alcohol may be used. Preferably the alcohol is selected from the group comprising ethanol, propanol and isopropanol. Preferably the proportion of alcohol is 25 per cent or less by weight. More preferably, the proportion of alcohol is between 1.0 and 3.5 per cent by weight. Still more preferably, the proportion of alcohol is between 1.0 and 3.0 per cent by weight. Still more preferably the proportion of alcohol is 2.7 per cent by weight.
Preferably, the mixture is capable of inducing temporary blindness and/or irritation in the mucus membranes in a human, and more preferably the mixture is capable of inducing blindness and/or irritation in the mucus membranes in a human for more than 5 minutes.
Preferably, the mixture is a liquid between the temperatures of -20°C and +50°C.
The mixture may comprise a dye or a marker or a UV dye or an Infrared dye or an optical brightener or a synthetic DNA tag. A synthetic DNA tag allows a sprayed individual to be linked to a particular batch of incapacitant spray.
One embodiment of the invention provides an incapacitant spray comprising a means for storing and delivering an incapacitant mixture according to the invention.
The storing means may be a can or a container.
The delivery means may be an aerosol, the mixture of the invention comprising an aerosol propellant, such as nitrogen, carbon dioxide, 1,1,1,2-tetrafluoro ethane (classified under CAS No, 811-97-2), dimethyl ether, butane, propane or oxygen. Preferably the propellant is nitrogen. Alternatively, the delivery means may use pressurised air to expel the mixture of the invention form the storing means.
The delivery means preferably includes a nozzle.
In one embodiment of the invention there is provided an incapacitant mixture comprising 0.3 per cent PAVA; a carrier being 72 per cent propylene glycol; 25 per cent water and 2.7 per cent ethanol, all by weight, and propellant therefor, the said propellant being nitrogen.
When an incapacitant spray is used in confined conditions it is inevitable that some overspray will occur. Substances with a boiling point which is greater than 100°C tend to have a slower evaporation rate than water. Propylene glycol, for example, has a boiling point of 187°C and also has a very slow evaporation rate, slower than that of water. Ethanol has a boiling point of 78°C and has a much higher evaporation rate than water. As a result of this the incapacitant mixture of the invention has a much slower evaporation rate than an equivalent mixture with an alcohol/water based solvent. This is of great advantage as the PAVA in any overspray remains in solution for a longer period of time and can be easily cleaned by simply wiping away and this lessens the effect of cross-contamination.
Glycerine, and glycols, for example propylene glycol, have a higher surface tension than water, which in turn has a higher surface tension than an alcohol. Adding a proportion of an alcohol, for example ethanol, to a glycol or a glycol/water mixture lowers the surface tension of that mixture. It may be desirable to provide an incapacitant mixture with a lower surface tension. For example if an incapacitant spray is sprayed above the eyes of a person it may be desirable that the surface tension of the mixture is low enough to allow the mixture to run down into the eyes. This can be achieved by the addition of an alcohol to the mixture.
In windy conditions, or on impact with a surface, a spray may be broken up into droplets. The size of the resulting droplets increases with the surface tension of the liquid. The incapacitant mixture of the invention has a higher surface tension than known incapacitant mixtures comprising with an alcohol and water based solvent. The incapacitant mixture of the invention will therefore will break up into larger droplet sizes. This is illustrated in the following examples:

a) An incapacitant mixture having 0.3 per cent PAVA and a solvent comprising 50 per cent ethanol and 50 per cent water, and nitrogen as propellant was prepared.
Droplet size distribution was measured from repeated short bursts of the mixture from a canister placed at distances of 1.0m, 2.0m and 3.0m from the measurement location. On average it was found that 79% of droplets resulting from the spray had a diameter of more than 10 micron.
b) An incapacitant mixture according to the invention having 0.3 per cent PAVA, 72.0 per cent propylene glycol, 25.0 per cent water and 2.7 per cent ethanol (all by weight), and nitrogen as a propellant was prepared.

Droplet size distribution was measured from repeated short bursts of the mixture from a canister placed at distances of 1.0m, 2.0m and 3.0m from the measurement location. On average it was found that 99.18 per cent of droplets resulting from the spray had a diameter of more than 10 micron.
Droplet sizes of more than 10 micron are unlikely to be inhaled into the human respiratory system in significant quantity. Inhalation of an incapacitant mixture causes a cough reflex response. The incapacitant mixture of the invention therefore provides a reduced cough reflex response compared to known incapacitant sprays.
The mixture of the invention does not have any significant effect on the respiratory system, yet causes temporary blindness which is exceptionally effective in incapacitating humans. The person must be incapacitated during the journey to a police station for instance until he is locked in a cell. A person may be dosed repeatedly witch the incapacitant of the invention, in order to keep him under control when the effects of one application begin to wear off.
Blindness results from intense pain in the eyes which causes the eyelids to close involuntarily rendering the person blind until such time as the effect of the incapacitant wears off. In the case of incapacitation resulting from irritation to the mucus membranes this is also a result of intense pain, felt in areas exposed skin covered with mucus membranes and immediately adjacent such areas of skin. Hence, if for some reason the incapacitant is prevented from entering the eyes, the person may nevertheless be incapacitated by intense pain in and around the nose and mouth. However, due to the comparatively large droplet size the incapacitant mixture of the invention does not have any significant effect on the respiratory system. Whilst the mixture causes the tear ducts to swell and some tears to be produced, these are a side effect. Intense lachrymation is not the cause of incapacitation.

Examples

1. An incapacitant mixture according to the invention having 0.3 per cent PAVA, 72.0 per cent propylene glycol, 25.0 per cent water and 2.7 per cent ethanol (all by weight), and nitrogen as a propellant was prepared. The incapacitant mixture had a surface tension similar to that of water.
The incapacitant mixture was sprayed at a person in the region of the eyes. The incapacitant caused irritation of the eyes, thereby incapacitating the said person. The eyes watered in connection with the irritation caused by the incapacitant.
2. An incapacitant mixture according to the invention having 0.3 per cent PAVA, 73.7 per cent propylene glycol, 25.0 per cent water and 1.0 per cent ethanol (all by weight), and nitrogen as a propellant was prepared.
The incapacitant mixture was sprayed at a person in the region of the eyes. The incapacitant caused irritation of the eyes, thereby incapacitating the said person. The eyes watered in connection with the irritation caused by the incapacitant.
The incapacitant mixture was also sprayed at a person wearing protective goggles, directly at the nose and mouth. The incapacitant caused irritation of the mucus membranes and intense pain in the mouth and nose, thereby incapacitating the said person. Even though the incapacitant is not sprayed into the eyes, the eyes may nevertheless water in connection with the irritation caused by the incapacitant.
With a concentration of 1.0 per cent ethanol the incapacitant mixture had a higher surface tension compared to water.

Claims

A liquid phase incapacitant mixture comprising pelargonic acid vannillylamide (PAVA) and a carrier, wherein the mixture induces temporary blindness and/or irritation in the mucus membranes in a human or animal, and wherein the carrier is miscible with water and has a boiling point greater than that of water, and includes a water-miscible solvent selected from the group comprising glycerine and glycols in a proportion of 50 per cent or more by weight of the mixture and the carrier further comprises water and an alcohol, and wherein PAVA is the primary incapacitant in the mixture, the proportion of PAVA in the mixture being 0.65 per cent or less.
An incapacitant mixture according to claim 1, wherein the proportion of PAVA in the mixture is between 0.3 and 0.65 per cent by weight, or wherein the proportion of PAVA in the mixture is between 0.3 and 0.6 per cent by weight.
An incapacitant mixture according to claim 1, wherein the proportion of glycerine or glycol in the mixture is 60 per cent or more by weight, or wherein the proportion of glycerine or glycol in the mixture is 72 per cent by weight.
An incapacitant mixture according to any preceding claim, wherein the water-miscible solvent is propylene glycol.
An incapacitant mixture according to any preceding claim, the carrier further comprising water in a proportion of 30 per cent or less by weight of the mixture, or the carrier further comprising water in a proportion of between 20 and 30 per cent by weight of the mixture.
An incapacitant mixture according to any preceding claim, wherein the proportion of alcohol in the mixture is 25 per cent or less by weight, or wherein the proportion of alcohol in the mixture is between 1.0 and 3.5 per cent by weight, or wherein the proportion of alcohol in the mixture is 2.7 per cent by weight.
An incapacitant mixture according to any preceding claim, wherein the alcohol is selected from the group comprising ethanol, propanol and isopropanol.
An incapacitant mixture according to any preceding claim, comprising 0.3 per cent PAVA, 72 per cent propylene glycol, 25 per cent water and 2.7 per cent ethanol, all by weight.
An incapacitant spray device comprising means for storing and delivering an incapacitant mixture as defined in any of claims 1 to 8.
An incapacitant spray device according to claim 9, wherein the means for delivering the incapacitant mixture comprises an aerosol propellant.
An incapacitant spray device according to claim 10, wherein the propellant is selected from the group comprising nitrogen, carbon dioxide, 1,1,1,2-tetrafluoro ethane, dimethyl ether, butane, propane and oxygen.
An incapacitant spray device according to claim 9, wherein the delivery means comprises a source of pressurised air to expel the mixture from the storing means.
An incapacitant spray device according to any of claims 9 to 12, wherein the storing means is a can.