GB2105194A

GB2105194A - Fumigation dispenser

Info

Publication number: GB2105194A
Application number: GB08223974A
Authority: GB
Inventors: Trevor Cyril Harper
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-09-08
Filing date: 1982-08-20
Publication date: 1983-03-23
Also published as: ZW17982A1; MW3581A1; ZA826130B

Abstract

A dispenser for fumigants of the type that liberate toxic fumes on exposure to atmosphere, such as metal phosphides which hydrolise to liberate phosphine comprises a support (1) to hold plates (10) or flat sachets of fumigants such that the front and rear faces thereof are exposed to the atmosphere. The dispenser also provides a sealed container for the fumigant, with the dispenser having moisture-proof coverings, at least in parts, that can be broken and removed to expose gas-pervious areas or windows 6. <IMAGE>

Description

SPECIFICATION Fumigation dispenser means The present invention relates to a fumigation dispensing means to accommodate a fumigation device including a composition which by exposure to the atmosphere liberates a toxic fumigation gas, the dispensing means being adapted to permit access of the ambient atmosphere to the fumigation composition.

The present invention is particularly intended for use with fumigation devices including a metal phosphide composition such as a composition comprising aluminium phosphide or magnesium phosphide and suitable additives which by exposure to atmospheric moisture reacts to release poisonous phosphine gas.

One commercially available fumigation device of this kind is in the form of a panel or plate of material approximately 22 x 17 cm in size. The composition incorporated in this panel is based on magnesium phosphide and paraffin wax. It is known in the trade as a "fumigation plate". It may be used to fumigate stacks of agricultural produce under gas-tight covers or produce in sealed warehouses, sealed railcars and ocean containers. The manufacturers market the plates in sealed tins, and each plate is individually sealed in a foil envelope. The tins in which the plates are packed are clearly labelled and readily identifiable. Each plate is marked with written instructions stating which it is and what it is to be used for.However, after exposure to the atmosphere and resultant decomposition of its magnesium phosphide content, the surface texture changes, and the clarity of the markings becomes obscured.

In order to expose the fumigation plate to the atmosphere, the plate is removed from the covering foil, and once sufficient moisture has entered the composition the hydrolysis reaction sets in by which hydrogen phosphide (phosphine gas) is formed and released. Direct contact with liquid water must be avoided in order to prevent the hydrolysis reaction from becoming too violent, because this could result in the auto-ignition of the phosphine. However, the commercial product is not adapted to be suspended in any way and accordingly the user of the product normally has no choice but to place the plates on the ground where the potential risk of contact with liquid water is greatest.

This type of metal phosphide, particularly aluminium phosphide and especially magnesium phosphide, have the desirable properties that the phosphine gas is highly poisonous, that exposure to ambient atmosphere provides sufficient moisture for the reaction, and that no harmful residues remain afterthe fumigation. The last property arises from the fact that no solid poisons are generated or expelled from the fumigation plate, while the phosphine gas itself eventually reacts to form phosphoric acid which is not dangerous or harmful in the quantities which become present. However, there is also the undesir able property that phosphine gas is highly inflamm able and has a low ignition temperature.Thus, ignition of the phosphine gas may occur where there is localised heating ofthefumigation plate, particularly where there is also a high concentration of the phosphine gas. Such a situation may arise where this is inadequate ventilation of the fumigation plate or localised, insufficiently ventilated exposure of the plate to ambient moisture.

After a fumigation of a space has been completed, the spent fumigation device must be retrieved from the space for disposal. In normal circumstances this requires first throoughly aerating the space until the toxicity ofthe atmosphere has been reduced to a safe level allowing entance for the retrieval of the spent fumigation plates. Again, ifthefumigation plates had attachment meant for securing them to a place readily accessible from the outside as soon as a door or hatch or like opening of the railway car, container, warehouse or the like is opened, this delay for aerating the space might be avoidable.

Aluminium phosphide compositions have also been commercially available in powder form, packed in portions of safe sizes in crepe paper sachets, These sachets are normally loosely laid out in a space to be fumigated in a manner similar to what is done with the aforesaid fumigation plates. However, prior art sachets are also known which are fitted with eyelets and/or strings by which they can attached to one another and to suitable supports.

Applicators have also been described which are designed to accommodate a large number of the aforesaid sachets in separate pockets out of control with one another and designed quickly to spread out a large number of sachets on a floor or on top of commodities to be fumigated.

However, there is still a need for more convenient fumigant dispensing means forthe fumigation plates aforesaid and also for individual sachets, particularly if are not fitted with eyelets or similar suspension devices.

In accordance with one aspect ofthe present invention there is provided a fumigating dispenser means to accommodate a fumigation device that has a front face and a rear face and that includes a composition which liberates toxic fumes on exposure to the atmosphere, comprising a stiff back panel, a front support which is gas pervious or has gas pervious areas or has windows for exposing the front face of the fumigation device to the ambient atmosphere, side members connecting each side of the front support to the back panel to form a space to receive fumigation device with the fumigation device spaced from the back panel by a space is communication with the ambient atmosphere and exposed to the rear face ofthe fumigation device, and attachment means for attaching the fumigation dispensing means to an inner side - or ceiling-surface of a compartment to be fumigated.

The attachment means may take the form of an eyelet or a punched hole or the like, preferably in an edge, more particularly the top edge of the envelope, which edge should be made of a relatively strong and preferably stiff material, e.g. cardboard, or be reinforced therewith. Alternatively, or in addition the attachment means may take the form of self-adhesive regions on the back of the dispensing means.

The front support may be a panel which may be stiff or flexible, e.g. made of paper, cardboard or foil, formed with at least one gas pervious area or win dow, or may comprise a number of strips of suitable material with one of the strips forming a supporting gutter formation.

The dispenser may be made wholly or partly of material sufficiently vapour pervious to allow entrance of atmospheric humidity to the fumigation composition. Alternatively one or more window openings may be provided for such access. The vapour pervious material may be a suitable non-woven, fine pored material, such as crepe or tissue, or may be an open net-like material.

The space inside the dispenser means may be open at its top end for the insertion of the fumigation plate or similar device. A spacer, such as a tab or flange may be provided on the back panel to hold a fumigation device away from the back panel.

The device may have areas for printed or written matter, including such information as the nature of the fumigation device or composition and instructions for use and in particular instructions for disposal of the spent device with or without the dispensing means.

According to another aspect of the invention the dispenser means is formed simultaneously as a packet for the fumigation device. For this purpose the entire dispensing means with the fumigation device contained therein may be hermetically sealed inside a moisture-proof envelope of foil or like material.

Alternatively the dispenser means itself is partly made of moisture-proof foil covering the remainder of the means, including the fumigation device contained therein, the foil being adapted to be broken and torn open in order to expose the fumigation device to atmospheric humidity. This package is especially suitable for metal phosphides.

According to yet another aspect of the invention there is provided a method of fumigating a compartment including the steps of :- inserting a fumigation device that has a front face and a rear face and that includes a composition which liberates toxic fumes on exposure to the atmosphere into a dispenserthat has a stiff back panel, a front support and side mem bers connecting the front support to the back panel; forming at least one gas pervious area or window in the front support in communication with the front face of the device; and spacing the rear face of the device from the back panel by a space that is in com munication with the rear face of the device and with the ambient atmosphere.

In the following the invention will be further explained with reference to the accompanying draw ings.

Figure 1 represents a front elevation of one embod iment of a dispensing means according to the inven tion; Figure 2 represents a rear view of the device shown in Figure 1; Figure 3 represents a side elevation of the device according to Figures 1 and 2; Figure 4 represents a front elevation of an alterna tive embodiment of the dispensing means in accor dance with the invention; Figure 5 represents a rear view of the device accord ing to Figure 4 Figure 6 represents a view similar to Figure 4 but with a fumigation plate shown in position and Figure 7 represents a side elevation of the device in accordance with Figures 4 to 6 including the fumigation plate whilst in use.

Referring to Figures 1 to 3,the dispensing device in accordance with the invention comprises a stiff rear panel 1 having a reinforced top edge 2 and a front panel 3 of paper or cardboard, the panels 1 and 3 being interconnected on three sides by a gusset of open, net-like material or vapour pervious material such as crepe or tissue or perforated paper 4 to form an envelope which is open at the top end 5. The front panel 3 comprises an open window area 6 and an area 7 for printed information, in particular disposal instructions. The top edge 2 has a hole 8 punched thereinto for suspending the device from a hook or nail or the like or with the aid of a cord or piece of string inserted through the hole. A foldable tab or flange 16 of cardboard is provided on the back panel.

In addition or in the alternative to the hole 8 the back panel 1 of the device comprises self-adhesive areas 9 for adhesively sticking the device onto a wall, a door or the like.

In use the apparatus according to Figures 1 to 3 is attached to a wall or door or similar vertical surface and a fumigating plate or equivalent device is inserted through the open top 5 into the envelope 1, 3, 4, where it is left until the metal phosphide composition of the device has been completely decomposed by the hydrolysing action of atmospheric humidity.

The device is diagrammatically indicated in broken lines 10.

According to a modification of the embodiment illustrated in Figures 1, 2 and 3, the device there shown is made entirely of moisture-proof material and the top 5 of the envelope is closed. The window area 6 is covered by a moistu re-prooftear away foil in order to expose the device 10 packaged nside to the atmospheric humidity.

In accordance with a further modification of the last-mentioned embodiment the window 6 is replaced with a vapour pervious material and is dimensioned to span at least a major portion of the fumigation plate. All such vapour pervious areas of the package are temporarily covered by a moistureproof tear-off strip of foil which, once it is drawn off exposes the package's contents 10 to the humidity through the perforations in the gussets.

Referring now to the embodiment in accordance with Figures 4 to 7of the drawings, the device there shown comprises a rear wall 11 of stiff moistureproof material, the top edge of which again is formed with an aperture 8 and on the rear of which selfadhesive areas 9 are provided. Near the bottom edge of the panel 11 there is provided a gutter formation 12, the open top of which is upwardly directed and dimensioned to receive the lower edge of a fumigating plate 13 which is only illustrated in Figures 6 and 7. The top of the plate 13 is embraced and thus supported by a ribbon or strip 14 of the paper, textile or foil.

Once again this device may be used as a combination package in which case the front of the complete device is covered and sealed hermetically to the panel 11 by a humidity-prooffoil 15, the panel 11 being of a humidity-proof material. Figure 7 shows this foil in its torn-away condition, thus exposing the plate 13 to atmospheric humidity.

An advantageous feature of the embodiments described above is that the dispenser ensures that there will be adequate ventilation of the metal phosphide fumigation plate. In this respect it will be seen that when the dispenser is suspended from a ceiling or a wall the fumigation plate will rest against the front support, i.e. front panel 3 or strip 14, and thus be spaced from the back panel 1 and 11 by a space which is in communication with the ambient atmosphere eitherthrough the open top or through such open top and the sides. Moreover the front face of the fumigation plate will be exposed to the atmosphere. Therefore, there is little likelihood of the phosphine gas forming in concentrated packets and localised heating will be, at least, minimized.Another advantage of these embodiments is that the fumigation plate can be positioned in a space to be fumigated at a place convenient for installation and withdrawal.

It is to be understood that this invention is not limited to the precise constructional details shown in the drawings and described herein and modifications may be made without departing from the spirit of the invention. For example the tab or flange 16 shown in Figure 3 may also be provided in the embodiment of figures 4 to 7. Also the material or net providing the vapour pervious areas may for simplicity be formed as a sleeve with the back panel 1 or 11 being inserted in the sleeve and optionally secured thereto. Another variation is to use a magnetic element such as a pad or strip of appropriate metal or metal embedded in plastics (for example flexible magnets) for attaching the dispenser to a surface of the compartment to be fumigated. This magnetic element may be stapled, pinned or bonded to the back of the dispenser or it may be loose in the dispenser.

Claims

1. A fumigating dispenser means to accommo date a fumigation device that has a front face and a rear face and that includes a composition which liber ates toxic fumes on exposure to the atmosphere, comprising a stiff back panel, a front supportwhich is gas pervious or has gas-pervious areas or has win dows for exposing the front face of the fumigation device to the ambient atmosphere, side members connecting each side of the front support to the back panel to form a space to receive a fumigation device with the fumigation device spaced from the back panel by a space in communication with the ambient atmosphere and exposed to the rear face of the fumigation device, and attachment means for attach ing the fumigation dispensing means to an inner side or ceiling-surface of a compartmentto be fumigated.

2. Means as claimed in claim 1, in which the attachment means comprises an edge portion formed with a hole by use of which the fumigation dispensing means may be suspended from the sur face.

3. Means as claimed in claim 1 or claim 2, in which the attachment means comprises at least one self adhesive member provided on the back panel.

4. Means as claimed in any of claims 1 to 3, in which the front support is a panel which is gas pervious or has gas pervious areas or has windows.

5. Means as claimed in any of claims 1 to 3, in which the front support comprises a gutterformation to support a lower portion of a fumigation device and a strip of suitable material spaced from the gutter formation, with the gutter formation and strip being arranged to support a fumigation device.

6. Means as claimed in any of claims 1 to 5, in which the side members are flexible with at least part of the front support being movable between a first position in which it is adjacent the back panel and a second position in which it is spaced from the back panel.

7. Means as claimed in any of claims 1 to 6, in which the gas-pervious material is a sheet of nonwoven material with fine pores.

8. Means as claimed in any of claims 1 to 6, in which the gas-pervious material is an open, net-like material.

9. Means as claimed in any of claims 1 to 8, in which flange or tab means is provided on the back panel for spacing a fumigation device away from the back panel.

10. Means as claimed in any of claims 1 to 9, having areas for printed, written, stamped and the like information matter.

11. Means as claimed in any of claims 1 to 10, in which the space formed between the back panel and the front support is open along at least one side thereof through which a fumigation device may be inserted into the space.

12. Means as claimed in any of claims 1 to 11, wherein the means itself in a closed position forms a moisture-proofcontainerfor a fumigation device and is openable to expose the fumigation device to ambient atmosphere.

13. Means as claimed in claim 12, in which at least part of one of the back panel, front support and side members is of a moisture-proof material that is sealed to a moisture-proof, at least partially removable covering that covers the remainder of the dispenser means.

14. Means as claimed in any of claims 1 to 11, in which the fumigation dispensing means is sealed in a moisture-proof envelope.

15. A fumigation dispensing means substantially as herein described with reference to or substantially as illustrated in any of figures 1 to 3 orfigures 4to 7 of the drawings.

16. A fumigation package comprising a fumigation dispensing means as claimed in any of claims 1 to 15 with a fumigation device sealed against exposure to the atmosphere.

17. A fumigation package comprising a stiff back panel, attachment means for attaching the back panel to a surface of a compartment to be fumigated, a front support, side members connecting each side of the front support to the back panel and forming a space, and a fumigation device in the space, the fumigation device being sealed against exposure to the atmosphere by a moisture-proof material that is at least partially removable.

18. A fumigation package substantially as herein described with reference to or substantially as illustrated in any one of figures 1 to 3 or figures 4 to 7 of the drawings.

19. In combination a fumigation dispenser means as claimed in claim 1 and a fumigation device in position in the fumigation dispensing means and exposed to the atmosphere.

20. The combination of claim 19, in which the fumigation device is in the form of a plate or panel.

21. The combination of claim 19, in which the fumigation device is in the form of a socket.

22. The combination of any of claims 19 to 21, in which the fumigation device includes a metal phosphide.

23. The combination of claim 22, in which the metal phosphide is magnesium phosphide.

24. A method of fumigating a compartment including the steps of inserting a fumigation device that has a front face and a rearface and that includes a composition which liberates toxic fumes on exposure to the atmosphere into a dispenser that has a stiff back panel, a front support and side members connecting the front support to the back panel; forming at least one gas pervious area or window in the front support in communication with the front face of the device; and spacing the rear face of the device from the back panel by a space that is in communication with the rear face of the device and with the ambient atmosphere.

25. A method as claimed in clain 24, including the steps of attaching the dispenser to an inner side- or ceiling-surface of the compartment.

26. A method as claimed in claim 24 and substantially as herein described with reference to any of figures 1 to 3 or 4 to 7 of the drawings.

27. A fumigation dispenser means to accommodate a fumigation device that has a front face and a rear face and that includes a composition that liberates toxic fumes on exposure to the atmosphere, comprising a stiff back panel, a front support, side members connecting the front support to the back panel, the front support and side members being of a flexible, at least gas-pervious material for exposing the front face of a fumigation device positioned between the front support and back panel to the atmosphere, and spacer means provided on the back panel and arranged to abut a fumigation device positioned in the dispenser means to hold the fumigation device away from the back panel and form a space that is in communication with the rear face of the fumigation device and the atmosphere.

28. A dispenser means as claimed in claim 27, in which the spacer means is a flange or tab that is movable between a position in which it is substantially flush with the back panel and a position in which it projects from the back panel towards the front support.