DE3707453A1 - Method of pest control - Google Patents

Abstract

It is known to generate hydrogen phosphide, which is very suitable for the control of storage pests, from compressed articles etc. by hydrolysis of the metal phosphide on or in the goods to be treated. In the treatment of rooms, disadvantages are the long hydrolysis period with a period of action of several days, and the laborious removal of the powdery remains of the compressed article, which can contain up to 15% of undecomposed metal phosphide. The process according to the invention avoids the problems referred to. As a result of the use of gaseous hydrogen phosphide, which is withdrawn measured out in the amount necessary from a compressed gas cylinder via a pressure-reducing control and blown from outside into the object to be treated (mill, warehouse etc.) via a pipeline distributor spider having attached hose lines, the gas concentration necessary for the destruction of the storage pests present (insects in all stages of development, rodents etc.) is available virtually immediately. The disposal of the residues, which is laborious and encumbered with risks of environmental pollution, also does not apply.

Description

The invention relates to a method for the safe, environmentally friendly and product-friendly application of gaseous phosphorus to combat of storage and storage pests in all development stadiums as well as molds.

Such a method is very practical Interest, as it is known to be the good biocidal eigen Shafts of hydrogen phosphide used without which has so far been seen as a hindrance seeing residues and their safe and environmental consider gentle disposal to have to.

Gaseous phosphorus is usually used for the control of storage and storage pests from compounds of aluminum and / or magnesium phosphides developed. (Lit.) According to the specialist known processes produced powdery Preparations are either added to this in bulk Treating goods when entering e.g. Silo cells mixed or in containers made of textile materials such as. Paper bags or bags of moisture permeable plastics filled and to be acting goods added.

It is also known mixtures of active ingredients of the above Kind on, next to and under the goods under cover to be laid with gas-tight tarpaulins (bag stack fumigation).

In all cases the development of the gaseous takes place Phosphorus hydrogen by reaction of the aluminum or Magnesium phosphides with the humidity of the surrounding air cover.  

Another known dosage form of hydrogen phosphide developing preparations are pressed bodies in tablet or spherical form, whose drug content also from the reaction of Ambient humidity with aluminum and / or magnesium phos phid results. These compacts are also becoming better known measure the goods to be treated in a suitable manner given or outside the goods under gas-tight tarpaulins designed.

The previously known methods are also used in the control of pests in warehousing and manufacturing vacate. In addition, the use of Compacts of the composition described for the Control of subterrestrial rodents known. Here, pressed bodies are made individually or in groups introduced through the openings of the earthworks and develop inside the aisles by hydrolysis with the soil moisture gaseous phosphorus.

Common to all procedures is the constraint, which is called biocid develop known phosphorus in situ have to. The reaction of aluminum and / or magnesium phosphides with the surrounding moisture runs after one time-consuming process.

This process and the subsequent action time usually takes several days to a week and more. This is time consuming and prone to failure. So in practice it is only time-consuming and costly gastight sealing possible, the gaseous phosphorus during that caused by the slow decay of the compact Exposure time on the required for a satisfactory result level of concentration. Mishandling with the Sequence of multiple fumigations and consequently undesirable on Enrichment of the very toxic phosphorus on or in the treated goods are the result.  

A considerable disadvantage lies in the rest Residue from previous hydrolysis of aluminum and / or magnesium phosphides with the ambient humidity. Everyone in dealing with these pesticides Experienced is known to be still measurable and in part, by dependent on the nature of the application form, considerable Amounts of undecomposed aluminum and / or magnesium phosphide remain in the powdered reaction product. These residues have to be elaborate and not always harmless procedures collected and in eco logically correct way to be eliminated. Undecomposed residues can also poisoning and Start fires.

One that is often unavoidable is just as worrying Contamination of the treated goods either by direct Addition of the phosphides in tablet or spherical form or mixing the goods with the phosphides as soon as the enveloping paper and / or plastic bag tears and the Content with partly significant amounts of undecomposed phosphide remains in the goods. Set these operations when it is deal with the treated goods for human or animal nutrition is dealing with certain substances which Use of the gaseous phosphorus more or less narrow boundaries.

The increased fire risk must not go unmentioned, that collect when collecting the undecomposed residues results. Gaseous phosphorus forms with air mixed a mixture that can be ignited across wide limits. The expert is familiar with this fact and the public was and is often with news about spontaneous fires when collecting the partially still unzer faced residues.

Up until now, the expert opinion was considered to be unchallenged, that the direct application of gaseous hydrogen phosphide because of the tendency to spontaneous breakdown with simultaneous education ignitable gas-air mixtures are not possible. By inventing appropriate admixture of an inert gas could be achieved that the previous concerns could be resolved.

The invention has for its object the distinguished The biocidal properties of the gaseous phosphorus to use hydrogen without the disadvantages described have to put up with the application.

According to the invention is gaseous hydrogen phosphide Filled and compressed in steel bottles in situ. The size of the steel bottle depends on the individual case required application rate.

For inerting and for easier emptying on the container according to the invention, 2-25% of an inert is used gases such as gaseous carbonic acid added.

At the place of application is carried out in a known manner Sealing of the building, large container, rodent building, etc. the gaseous phosphorus hydrogen via a pressure reducing / Fine adjustment valve as well as via manifold valves and hose Plastic pipes from outside into the room to be fumigated initiated (e.g. buildings, silo cells, ship holds etc.).

That kind introduced hydrogen phosphide mixes according to the kinetic gas laws with the existing indoor air and has stood for the very first minute of its development Combat of camp and storage pests available. Because of this and because of the elimination of the previously known methods and means required long Start-up time is reduced for the safe fighter  the necessary action by the storage and storage pests time to a maximum of 30 hours. The previous minimum time amounts to 72 hours. If it is less favorable Accompanying circumstances such as low air humidity is the end so far the exposure time has been extended to 7-10 days required.

It is also advantageous in the method according to the invention the possibility of safe and can be done at any time Subsequent dosing with a possibly decreasing gas concentration.

Another advantage is occupational safety justified: While all previously known and in the methods used in practice, the application in Inside the building etc. must be done and because of respiratory protection devices that are not usually used poisoning cannot be excluded in individual cases, can the introduction of the gaseous phosphorus outside safely outside. For this purpose, one appropriately uses a suitable one Measuring device (gas meter, buoyancy meter, etc.).

Another advantage of the use of gaseous phosphorus hydrogen according to the invention lies in the complete absence in some cases. residues not completely decomposed.

For the first time in the history of using aluminum and / or pesticides containing magnesium phosphide possible, the very narrow limits for a reason today to comply with environmental protection:

The gaseous hydrogen phosphide used after the specified exposure time by opening the windows, doors etc. in the surrounding Release atmosphere where, due to the influence the UV radiation converted to non-toxic phosphoric acid becomes. There are no residues and the strict Food legislation and environment regulations protection is fully met.  

Care is also taken to avoid this unnecessary contamination of the operating personnel the human toxic gaseous phosphorus. This is for long-term toxicology of great importance.

Gaseous phosphorus in the Darge according to the invention form can now also be used for the first time to combat Mold infestation on goods of all kinds in gas-tight sub-areas pressure chambers are used.

The air removed at the start of the operation (this is for the subsequent penetration, especially of densely packed ones Were indispensable) so far has been necessary for hydrolysis Humidity removed and then stood for development gaseous phosphorus as aluminum or magnesium formulations containing phosphide are no longer available.

The use of the gaseous substance presented according to the invention Phosphorus hydrogen in vacuum chambers can now do this replace common methyl bromide, which because of its Ein classification as a carcinogenic substance met with great aversion.

Claims (9)

1. A process for the safe, quick and effective use of gaseous phosphorus, characterized in that gaseous hydrogen chloride is blown off in a pre-stressed form from a steel bottle of a commercially customary form and type after an inert gas in the amount of 2-25% has been previously added to it. 2. The method according to claim 1, characterized in that that preferably as an inert gas, but not from finally carbonic acid is added as a gas. 3. The method according to claim 1 and 2, characterized net that the hydrogen phosphide inert gas mixture to a reduction and / or fine adjustment valve Back pressure of 1.5 to 10 bar is set. 4. The method according to claim 1 to 3, characterized in net that turned on a suitable back pressure set hydrogen phosphide inert gas mixture by System of manifold valves and plastic hoses inside buildings, silo cells, ship's drawer evacuate and others, suitably the damage Combating pest control with very toxic gases and previously made rooms sufficiently gas-tight is blown.   5. The method according to claim 1 to 4, characterized in that the gas concentrations during the short exposure time tration inside the building etc. in a known manner measured and in the presence of leaks and resulting undesirable decrease in gas concentration at any time from the storage container Phos hydrogen phosphide-inert gas mixture can be replenished. 6. The method according to claim 1 to 6, characterized in that measuring the amount of gas needed over a measurement device is done. 7. The method according to claim 1 to 6, characterized. that when a phosphor is used as intended hydrogen-inert gas mixture no residues of toxi environmentally or ecologically relevant substances remain. 8. The method according to claim 1 to 7, characterized in that a mixture of hydrogen phosphide and inert gas in gas tight, welded steel chambers in negative pressure an initial negative pressure of e.g. 40 mg Hg for Application comes and there to combat mold mushrooms and spores. 9. The method according to claim 1 to 6, characterized in that a hydrogen phosphide inert gas mixture in input openings of rodents living subterrestrically in practical dosage is blown.