AU5103793A - Containers for potentially hazardous substances - Google Patents

Description

CONTAINERS FOR POTENTIALLY HAZARDOUS SUBSTANCES

The present invention relates to containers for potentially hazardous substances such as pathological samples, diagnostic products, or infectious substances (hereinafter referred to as "pathological samples") and more particularly to containers for the transport of pathological samples by post or by road, rail, air or sea.

Conventionally, pathological samples such as blood specimens are stored in a closed bottle or tube for transportation to a pathology or research laboratory for analysis. When the container needs to be sent by post, road, rail, air or sea transport to the laboratory, the container is placed within outer packaging the primary purpose of which is to protect the container against damage if the package is dropped, crushed or is otherwise subjected to mis- treatment during handling. Generally, prior methods of packaging the containers have not been entirely satisfactory and breakage of the container and/or leakage have occurred, resulting in contamination of the outer packing. A particular problem with air-freighting is the container may be subject to substantial temperature and pressure variations, particularly in an unpressurised hold, and this can give rise to leakage.

According to the present invention, there is provided a package for the transport of pathological or other substances, comprising an outer tubular container having at one end closure means for sealing the outer container against leakage, and an inner tubular container supported within the outer tubular container and having, at one end, closure means to prevent leakage of fluid from the inner container, the inner container being supported within the outer container such that the tubular wall of the inner container is spaced from the tubular wall of the outer container and the opposite ends of the inner container are spaced from the opposite ends of the outer container.

Preferably, the inner container includes an external annular flange on its tubular body which is supported from a zone of reducing cross-sectional area within the interior of the outer container or from a step within the interior of the outer container.

Preferably, the inner and outer containers each consist of a preform for a plastics bottle.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, the sole figure of which shows, schematically, a longitudinal section through a transportation package in accordance with the present invention.

As shown in the accompanying drawings a package for the transportation of pathological samples or other potentially hazardous material comprises an inner elongate tubular container 2 for storing the sample, the container 2 being supported within an outer tubular container 4 which protects the inner container 2 against damage but which is able to contain leakage if the integrity of the inner container 2 is damaged. The inner container 2 is closed at its lower end and is open at its upper end, the upper end being threaded to receive a threaded closure cap 6. The cap 6 includes an internal seal in order to prevent leakage of fluid from the inner container 2. The cap 6 may also include a tamper-resistant element 6a to provide a visual indication of unauthorised removal of the cap. An annular flange 8 is formed integrally with the body of the container 2 beyond the threaded zone at which the cap 6 is fitted and serves to support the inner container 2 within the outer container 4 with the longitudinal axes of the two containers being substantially coincident. The outer container 4 is also of tubular form closed at its lower end and open at its upper end and is externally threaded at that end to receive a threaded closure cap 10 which includes an internal seal in order to prevent leakage of fluid from within the outer container. The cap 10 for the outer container may also include a tamper-resistant element 10a to indicate unauthorised removal of the cap. The wall thickness of the outer container 4 increases from the upper end portion to a larger thickness extending along a substantial portion of the length of the container, the portion of lesser thickness being connected to the portion of greater thickness by a portion of progressively increasing thickness which defines within the interior of the container a zone 12 of progressively reducing cross-sectional size. The diameter of the flange 8 on the inner container 2 is such that the flange 8 is able to support the inner container 2 within the outer container 4 by wedging within the zone 12; as shown the support is at the commencement of the zone 12. The two containers 2, 4 are so sized that when the flange 8 on the inner container 2 is wedged within the zone 12, the wall of the inner container 2 is spaced from the wall of the outer container 4 and the closed end of the inner container 2 lies short of the closed end of the outer container 4. If required, when the sample has been introduced into the inner container 2 and the closure cap 6 for the inner container 2 has been applied, resilient packing material, for example a resilient foam plug, can be inserted into the open end of the outer container 4 to cushion the inner container 2 against possible displacement towards the cap 10 of the outer container 4 due to shock loading. Preferably, a stop 14 is provided at the bottom of the outer container 4 to limit excessive displacement of the inner container 2 towards the bottom of the outer container 4 and which might result in the flange 8 becoming jammed within the zone 12 whereby subsequent removal of the inner container 2 might be impossible. The stop 14 can be a separate component inserted into the container 4 after manufacture of the container 4, or the container 4 can be integrally formed with a suitable stop for example in the form of a peg upstanding from the bottom wall.

Preferably, the outer container 4 includes, for example at its bottom portion, absorbent material such as crystals or a so-called super absorbent for absorbing the whole of the contents of the inner container in case the latter leaks.

In an alternative embodiment the flange 8 on the inner container can be supported on a step formed on the inner surface of the outer container. The inner and outer containers 2, 4 are preferably constructed from a non-brittle, flexible, plastics material such as PET, PETG, polycarbonate, or PNC. The caps 6, 10 for the inner and outer containers 2, 4 are also preferably constructed from a non-brittle plastics material such as high density polyethylene, PET, PETG, polycarbonate, or bakelite. The internal seals within the caps 6, 10 may, for example, be of low density polyethylene, EVA, or PNC.

The package consisting of the inner and outer containers is placed within a suitable box or other outer wrapping for carrying address information and other data. The box may, for example, consist of foamed polystyrene or other foamed plastics material having a compartment shaped to securely house the package and particularly to protect the cap of the outer container which is likely to represent the weakest part of the package unless a high strength plastics is used for the cap. The box may have several individual compartments so that several packages can be transported within the same box.

The combination of the two containers described provide a package which is not liable to leakage even with gross mis-handling including dropping and crushing. The package can contain such pressure differentials as may be encountered during air-freight even under the pressures and temperatures likely to be encountered within an unpressurised hold of an aircraft. The package when within a foamed plastics outer box as discussed above can also withstand impact tests and drop tests as currently prescribed by aviation authorities.

Although the inner and outer containers 2, 4 may be fabricated specifically for the purpose described, we have determined that a suitable inner container and outer container are each independently available as pre-forms of different size for subsequent fabrication into plastics bottles, for example for soft drinks, by expanding the pre-form by blowing within a mould. Such preforms will have the supporting flange required for the inner container and the varying wall thickness required for the outer container to provide the required co-operation with the flange. As such, the containers can be purchased at relatively low cost.

The embodiment has been described by way of example only with reference to the accompanying drawings and modifications are possible within the scope of the invention.

Claims (12)

CLAIMS:-

1. A package for the transport of pathological or other substances, comprising an outer tubular container having at one end closure means for sealing the outer container against leakage, and an inner tubular container supported within the outer tubular container and having, at one end, closure means to prevent leakage of fluid from the inner container, the inner container being supported within the outer container such that the tubular wall of the inner container is spaced from the tubular wall of the outer container and the opposite ends of the inner container are spaced from the opposite ends of the outer container.

2. A package according to claim 1, wherein the outer and inner containers are each of elongate tubular form, the longitudinal axis of the inner container is substantially coincident with the longitudinal axis of the outer container, and the respective closure means of the inner and outer containers are at the same end of the package.

3. A package according to claim 1 or claim 2, wherein the inner container includes an external annular flange at a position adjacent said one end of the inner container, said flange being engagable with means in the interior of the outer container to support the inner container within the outer container.

4. A package according to claim 3, wherein said means in the interior of the outer container comprises a zone of reducing cross-sectional area and within which the flange can wedge.

5. A package according to claim 4, further comprising stop means engagable with the other end of the inner container to prevent jamming of the flange within the zone of reducing cross-sectional area.

6. A package according to claim 3, wherein said means in the interior of the outer container comprises a step on which the flange can rest.

7. A package according to any one of claims 2 to 6, comprising means within the outer container at the other end portion thereof, for absorbing the contents of the inner container in the event of leakage.

8. A package according to any one of claims 2 to 7, further comprising resilient packing means interposed between the closure means of the inner container and the closure means of the outer container to cushion the inner container against displacement towards the closure means of the outer container in the event of a shock loading.

9. A package according to any one of claims 1 to 7, wherein the closure means for each container comprises a threaded cap having an internal seal.

10. A package according to claim 9, wherein the cap of at least one of the containers has means to indicate unauthorised removal of the cap.

11. A package according to any one of claims 1 to 10, wherein one or both of the inner and outer containers is provided by a pre-form for producing a plastics bottle by blow moulding.

12. A package according to any one of claims 1 to 10, wherein the inner and outer containers are of substantially similar shape and are composed of a non-britde plastics material.