WO1993012841A1

WO1993012841A1 - Apparatus and process for sterile disposal

Info

Publication number: WO1993012841A1
Application number: PCT/US1992/010956
Authority: WO
Inventors: Jonathan Bricken
Original assignee: D.O.C.C., Inc.
Priority date: 1991-12-30
Filing date: 1992-12-24
Publication date: 1993-07-08
Also published as: AU3414793A; IL104278A0

Abstract

An apparatus and process for sterile disposal of hazardous medical waste is provided. The apparatus includes a heat conductive container (12) for maintaining hazardous medical waste (14) and a means for applying heat to the heat conductive container (12) in an amount sufficient to deform the waste (14) into an unrecognizable state and render the waste sterile. The process for sterile disposal of harzardous medical waste in this manner is also provided.

Description

APPARATUS AND PROCESS FOR STERILE DISPOSAL

This is a continuation-in-part of application Ser. No. 07/600,258, now abandoned, which is a continuation of application Ser. No. 07/364,019, now abandoned.

Field of the Invention This invention relates generally to apparatus and processes for sterile disposal and in particular, to an apparatus and process for disposal of hazardous medical waste that renders the hazardous medical waste unusable and sterile.

Background of the Invention Hazardous medical waste is commonly generated in hospital environments as well as in health care clinics, dentist's offices, blood banks, dialysis centers, individual doctor's offices and even in homes by diabetics and the like. For example, syringes are used to inject fluids into the body or draw fluids from the body. In general, syringes include a plastic barrel in communication with a metal needle provided for insertion into a vein, muscle or the like. Liquid material to be injected into the body can be provided in the plastic barrel and dispensed through the needle which is in fluid communication therewith. Alternatively, body fluids can be withdrawn through the needle and collected in the plastic barrel. Because of the intimate nature of the- uses to which syringes are put, it is important that they be provided initially in a sterile condition. However, syringes are no longer sterile after use. Accordingly, disposal of used syringes has become a major health problem.

There has always been and continues to be a danger that a person will stab themselves with the needle of a used syringe. This danger is heightened in this day of infectious and deadly diseases such as AIDS, hepatitis and the like since it is not possible to know if the person who used the syringe had such a disease. Consequently, all used syringes have become suspect objects of fear and are subject to strict disposal standards.

Similar difficulties are encountered with all forms of hazardous medical waste. There has always been and continues to be a danger that hazardous medical waste will be mishandled during storage, transportation and disposal and cause life threatening infections to health care workers, carters, sanitation workers and the population at large. Mishandled hazardous medical waste also has the potential to adversely affect the environment by washing up on beaches or polluting groundwater following improper disposal in landfills.

To date, only one method for removal and disposal of hazardous medical waste has gained acceptance by the health care industry and federal, state and local governmental agencies. This method involves carting hazardous medical waste to a landfill or incineration facility. Some states do not have licensed landfill or incineration facilities and consequently, contaminated material is often hauled over extensive distances. As a result, millions of people and the environment are unnecessarily exposed to potential disasters that can result from mishandling or improper disposal of hazardous medical waste.

U.S. Patent No. 4,355,227 issued to Berard on October 19, 1982 discloses an apparatus for destruction of microfiche and the like. The microfiche are destroyed by placing the microfiche in a disposable tube fitted with a sealing plug, baking to a sufficient temperature to cause melting and discarded. The heat treatment of Berard is carried out at a temperature of between about 392° and 482°F (200° to 250°C) for a time period of between about 1 and 4 minutes.

U.S. Patent No. 3,958,936 issued to Knight, Jr. on May 25, 1976 discloses a plastics sterilizer and melter having an afterburner. The sterilizer melts plastic items at temperatures between about 400° and 600°F (204° to 316°C) for periods ranging between about one-half (1/2) and one and one-half (1-1/2) hours. U.S. Patent No. 5,003,892 issued to the named inventor herein on April 2, 1991 shows a process for sterile disposal of used syringes. The syringes are provided in a heat conductive container and heat is applied to the heat conductive container in an am unt sufficient to melt the syringe and cause the plastic to encapsulate the needle to form a molten mass and render the molten mass sterile. The temperature of the heat conductive container is raised to between about 380° and 450°F (193° to 232°C).

There remains a need for an apparatus and process for sterile disposal of all hazardous medical waste that effectively destroys the waste and renders the waste material sterile without requiring elaborate afterburner systems.

It is, therefore, an object of the invention to provide an apparatus that processes hazardous medical waste for sterile disposal.

Another object of the invention is to provide an apparatus for processing hazardous medical waste for disposal which biologically changes the character of the hazardous medical waste into a sterile state that is safe to handle and can be disposed of as ordinary garbage. A further object of the invention is to provide a process for reducing the volume of hazardous medical waste.

Still another object of the invention is to provide an apparatus and process for disposal of hazardous medical waste that melts the plastic materials in the waste including polyvinyl chloride (PVC), which is dangerous, volatile and unstable.

Still a further object of the invention is to convert hazardous medical waste into sterile garbage using a method the does not change the protocol currently practiced in the medical community.

Yet another object of the invention is to permit hazardous medical waste to be converte into sterile garbage at on-εite locations without filtration, venting or afterburning.

Even another object of the invention is to reduce potential human and environmental exposure to infectious material.

Even a further object of the invention is to eliminate the need for unnecessary and lengthy carting of hazardous medical waste.

Another object of the invention is to eliminate the need to incinerate hazardous medical waste prior to disposal. Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

Summary of the Invention Generally speaking, in accordance with the invention, an apparatus for preparing hazardous medical waste for sterile disposal is provided. The apparatus includes a heat conductive container for containing the hazardous medical waste to be prepared for disposal therein. A means for applying heat to the heat conductive container is also required. Heat is applied to the heat conductive container in an amount sufficient to melt plastic material contained in the waste and cause the plastic material to mix with the non-plastic material in a mass. The unreusable mass becomes sterile and does not need to be disposed of as infectious waste. The container is preferably removable from the apparatus and disposed of with the waste. A process for preparing hazardous medical waste for sterile disposal is also provided.

The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, and the apparatus embodying the features of construction, combination of elements and arrangement of parts which are adapted to effect such steps, all as exemplified in the following detailed disclosure, and the scope of the invention will be indicated in the claims. Description of the Drawings

For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of an apparatus for preparing hazardous medical waste for sterile disposal contructed and arranged in accordance with the invention;

FIG. 2 is a perspective view of the interior of an apparatus for preparing hazardous medical waste for sterile disposal constructed and arranged in accordance with the invention;

FIG. 3 is a schematic diagram showing the wiring and interlock features of an exemplary apparatus constructed and arranged in accordance with the invention;

FIG. 4 is a perspective view of an alternate apparatus constructed and arranged in accordance with the invention;

FIG. 5 is a perspective view of two heat conductive containers provided for use in the apparatus of the invention; and FIG. 6 is a cross-sectional view of several heat conductive containers after hazardous medical waste has been prepared for sterile disposal therein.

Detailed Description of the Preferred Embodiments

The hazardous medical waste disposal apparatus 10 constructed and arranged in accordance with the invention includes a heat conductive container 12 and a means for applying heat to the heat conductive container 12. As shown, the means for applying heat includes an oven assembly designated general ly as 20. A fan 90 is provided adj acent the heat conductive container 12 in order to accelerate cooling of the waste after the heat application cycle has been completed.

As used herein, the term "hazardous medical waste" refers to any regulated medical waste or non- sterile waste generated as a resul t of invasive human contact including, but not l imited to, syringes , paper products, polyvinyl chloride materials, and the like, but excluding body parts.

The heat conductive container 12 is provided for containing hazardous medical waste 14 that is to be prepared for s teri l e disposal . Heat conduc tive container 12 is constructed of any suitabl e heat conductive material such as, for example, a metal, metal al loy, glass or ceramic and certain high temperature resistant plastics. Suitable heat conductive metal s include, but are not limited to, aluminum, copper and the like.

Container 12 can be any suitable size or shape for holding medical waste 14. It is generally preferable to provide a container of a size and configuration that permits the medical waste to comfortably fit therein and in the case of needle and plastic syringe assemblies 14 to stand with the needle pointing downward, generally in the way that pencils stand in a pencil holder. It is contemplated that the containers can be of a size and configuration that permits multiple containers to be stacked prior to use.

Container 12 has at least one opening 16 which is used to place hazardous medical waste 14 into container 12. A lid 18 is provided to cover opening 16. Lid 18 can be any appropriate size or shape suitable for sealing opening 16, either permanently or temporarily. The lid 18 can be of any suitable type including, but not limited to, self-sealing lids, pop-on lids, screw on lids, twist-on lids, "child" resistant or tamper- resistant lids, and the like. Furthermore, a fusable material such as a solder 19 can be provided between the container 12 and the lid 18 so that when heat is applied to the container 12 the fusable material fuses the lid to the container 12. hether the lid 18 is of a permanent or temporary type is at least partially a function of whether the entire container 12 and lid 18 having treated medical waste 15 therein is to be disposed of or whether the mass 15 of medical waste 14 is to be removed from container 12 prior to disposal. Obviously, if the entire container 12, lid 18 and contents 15 are to be disposed of as a unit there is no difficulty in permanently sealing lid 18 to container 12 after an appropriate amount of hazardous medical waste 14 is placed in container 12. On the other hand, if the mass 15 of medical waste 14 is to be removed from container 12 after being subjected to heat treatment, then lid 18 must be removable from container 12 and permanent sealing is not appropriate.

In a preferred embodiment, the entire container 12 with lid 18 and contents 15 is disposed of after heat treatment. Accordingly, it is desireable for lid 18 to be permanently sealed to container 12 either prior to or during the heat treatment. Additionally, container 12 must be removable from apparatus 10 and replaceable with a new container 12. In carrying out this embodiment of the invention, it is a particularly advantageous feature if the top 17 of lid 18 and the bottom 13 of container 12 are cooperatively beveled so that used containers 12 with lids 18 secured thereto can be stacked for storage purposes. Any appropriate means for beveling lids 18 and container 12 so that multiple container 12 and lid 18 combinations can be stacked for storage is within the contemplation of the invention.

Container 12 is also preferably provided with a heat sensitive strip or indicator 40. The heat sensitive strip 40 is provided on the outside of container 12 or lid 18 so that it can be viewed when the container 12 is removed from the oven assembly 20 and is of a type that changes color at a specified predetermined temperature. The specified predetermined temperature should be the temperature t]aat the heat conductive container 12 must achieve in order to sterilize the waste 14 and is generally between about

340° and 360°F, preferably about 350°F. Accordingly, a user can determine at a glance whether the specified temperature has, in fact, been achieved during the heating cycle and therefore, whether the container 12 and its contents 15 can be disposed of as sterile waste.

As a separate optional feature of the lid construction of the invention, a one way opening for inserting medical waste 14 into container 12 can be provided either as part of lid 18 or as a separate underlid which will ultimately be covered by lid 18.

Such one way openings would provide an additional safety feature. The means f or app l ying heat to the heat conductive container may be any form of oven assembly, heating element or heater which meets the requirement of being capable of applying heat in an amount sufficient to heat the heat conductive container 12 with the hazardous medical waste 14 therein to a temperature of between about 340° and 360°F, preferably about 350°F for a first predetermined period of time. The predetemined period of time wil l be suff icient to s teril ize and render unusable al l hazardous medical waste. For

*-> example, when a container having a volume of about 71m is used, the first predetermined period of time is general ly about one (1) to one and one-half (1-1/2) hours. Consequently, any plastic material contained in the waste wil l mel t to form a mass and mix with the non- pl as tic material , and the entire mas s wi l l be sterilized. At temperatures less than about 340°F, plastics of a type used in the medical field do not mel t. At temperatures greater than about 360°F , polyvinyl chloride, starts to give of f noxious fumes. Furthermore, it is not desirable to apply heat at temperatures greater than those necessary to accomplish the desired result as this results in decreased energy efficiency.

The heat is to be applied for an amount of time sufficient to render the molten mass sterile. In a preferred embodiment of the. invention, the entire heat application cycle is between about one (1) and one and one-half (1-1/2) hours. This includes about one-half (1/2) hour for the heat conductive container to be brought to the desired temperature and about one half (1/2) to one (1) hour for the container to be maintained at the temperature achieved. It has been found that maintenance of the temperature achieved for less than one half hour will not permit the molten mass to be rendered sterile. In fact, New York state law requires that a temperature of at least 325°F be maintained for a period of one-half (1/2) hour in order to achieve sterility.

As shown in the drawings, the means for applying heat preferably includes an oven assembly designated generally as 20. Oven assembly 20 has a barrel 21 with a cover 32. The barrel 21 is of a suitable size for accomodating the heat conductive container 12 therein. A heater 30, which can be of any appropriate type, provides heat to barrel 21. In turn, barrel 21 conducts heat to the heat conductive container 12 so that hazardous medical waste 14 can be compacted to a molten mass and the molten mass rendered sterile.

Oven assembly 20 also preferably includes a temperature sensor 22 mounted on the wall of the oven assembly 20. The temperature sensor 22 is a ther ocouple which senses the temperature of oven assembly 20 and feeds the information to a temperature controller 24. The temperature sensor 22 also preferably includes a shut-off switch 23 which inactivates the entire system if the temperature of the oven assembly 20 climbs above a defined maximum temperature of generally about 360°F. The shut off switch 23 is normally closed and opens at about the defined maximum temperature.

The temperature controller 24 is a circuit designed to receive a signal from the temperature sensor 22. The controller 24 is preset to a desired temperature by setting the level within the controller. The signal received from the temperature sensor 22 is compared to the preset level defined by the controller 24. If the actual temperature of the oven assembly 20 is either above or below the set point of the temperature controller 24, the controller 24 lowers or raises the amount of power supplied to the heater 30 until the controller 24 no longer detects a difference between the two signals. The temperature of the oven assembly 20 is accurately maintained throughout the operating cycle by this feedback process.

Oven assembly 20 also preferably includes a timer 26 so that the length of the period of time for which heat is to be applied can be regulated. The timer 26 generally includes a circuit that closes or opens switch contacts for a specified time interval in response to a signal, which is preferably an electrical signal. The timer 26 is preset to a specified time interval prior to initiation of the heat application and hazardous waste destruction cycle and prevents oven assembly 20 from being opened during this preset time interval. In general, the preset time interval should be long enough to include the entire heat application and hazardous waste destruction cycle as well as a cooling period during which the container 12 and oven assembly 20 have an opportunity to cool down to a temperature at which they will no longer be harmful to an operator, generally about 90°F.

It is further contemplated that the function of the timer 26 and the temperature controller 24 can be performed by a printed circuit board 60. Such a circuit board 60 would be positioned within housing 29 adjacent a wall 62 as shown in FIG. 4. Circuit board 60 can also then be used to control appropriate information readouts on the outside of housing 29 as discussed in more detail below.

Oven assembly 20 preferably also includes a safety interlock system of the type shown in FIG. 3. The safety interlock system is a system of electrical or mechanical components within the hazardous medical waste conversion apparatus 10 that protects the operator from harm. In particular, the safety interlock system prevents initiation of a heating cycle unless the cover 32 of oven assembly 20 is in place, prevents removal of cover 32 when the temperature of the oven assembly 20 is above a predetermined maximum safe temperature of general ly about 90°F, and removes primary AC power from the entire system in the event of a temperature rise above a predetermined maximum temperature of generally about 360°F.

Cover detecting switch 34 forms part of the safety interlock system and prevents initiation of a heating cycle unless the cover 32 of oven assembly 20 is in place. Cover detecting switch is preferably a normal ly open, lever actuated type contact switch used to detect the presence of the oven assemb ly cover 32. The lever 35 is spring loaded to exert force upward against the cover 32. However, pressing the cover 32 downward overcomes the spring force and causes the lever to close the switch contact when cover 32 is positioned on barrel 21 of oven assemb ly 20. The heating cycle cannot be initiated until cover detecting switch 34 is closed.

" On" swi tch 3 6 i s a l s o a normal l y open momentary contact device that is closed by the action of an operator to begin a heating cyc l e. "On" switch 36 must remain closed in order for the heating cycle to continue and therefore, once the heating cycle has been initiated control of "On" switch 36 is governed by timer 26.

The safety interlock system also prevents removal of the cover 32 once the heating cycle has begun and the temperature of the oven assembly 20 exceeds a predetermined maximum safe temperature, generally about 90°F. An electromagnetic solenoid 38 includes a coil of wire wrapped around a hollow cylinder. A ferrous metal rod 46 is positioned within the hollow cylinder and is spring loaded so as to be maintained within the body of the cylinder until the coil of wire is energized. When the coil is energized, a magnetic field of opposite polarity to the coil is produced in the rod 46. This causes the rod 46 to be displaced from the body of the solenoid 38. In a preferred embodiment, the rod 46 is displaced linearly for a short distance of generally about one inch. Further displacement is prevented by a retaining ring at one end of. the rod 46 that contacts a cooperating ring in the interior of the hollow cylinder 44. In this energized state, the solenoid rod 46 is situated above the cover 32 and interferes with vertical movement of the cover 32.

The solenoid 38 can only be actuated for removal or insertion of the heat conductive container 12 when switch 62 and thermostat contact 64 are closed. The thermostat contace 64 is always closed when the oven as semb l y 2 0 is at a temperature l es s than some predetermined specified temperature, generally less than about 90°F. Switch 62 is a single pole s ingle throw contact switch that is actuated by the operator into a closed state amd remains in the closed state for the time necessary to insert or remove the heat conductive container 12. The circuit is completed only when the thermostat contacts 64 are c losed at less than the preset predetermined temperature of general ly less than about 90°F.

The thermostat contacts 23 remain closed at a predetermined maximum temperature of generally less than about 360°F. If a condition occurs that causes the temperature of oven as semb ly 20 to rise above that predetermined maximum temperature of general ly about 360°F the contact opens and interrupts the main AC power supply to the entire system.

In a preferred embodiment, the barrel 21 of the oven assembly 20 is insul ated with a suitab l e insulating material 48 to prevent destruction of the other elements of the system. One suitable insulating material 48 is a flexible ceramic type material having the appearance of cotton. The material may general ly have a thickness of between about 1/2 and 3/4 inches, preferably about 1/2 inch.

The entire oven assembly 20 is preferably incorporated in a suitable housing or enclosure 29. Enclosure 29 is preferably constructed of stainless steel and houses the entire system in such a way as to provide insulation to the temperature controller 24, timer 25, safety interlock and other components that might otherwise be damaged by exposure to the high temperatures generated by the oven assembly 20. In addition to the layer of insulation 48 formed around oven assembly 20, enclosure 28 also preferably employs appropriate venting and/or a fan or fans to create preferential air flow away from sensistive system components.

Appropriate information readouts can be provided on the exterior of enclosure 29 for the benefit of an operator. Such readouts preferably include one or more of the temperature of the oven assembly and/or the maximum temperature to which the heating cycle has been set 50, the cycle time and/or the amount of time remaining in the cycle wherein the cycle time is defined as either the heating cycle or the heating and cooling cycle 52, an emergency shut off switch 54 and a switch for initiating operation of the apparatus, an "on" switch 56. A l ight or other means for indicating that the apparatus is in operation can also be used.

To use the apparatus of the invention 10 , hazardous medica l was te 14 i s p l aced wi thin heat conductive container 12 and l id 18 is f i tted on container 12 to cover opening 16. The heat conductive container 12 is then placed within oven assembly 20 and cover 32 is secured to close cover detecting switch 34. If available, a timer 26 is set to the length of time for which the heat appl ication cycle is to continue and the temperature setting i s set to the maximum temperature which is to be achieved and maintained during the heating cycle. Switches 36 and 62 are closed by initiating the heating cycle from a switch on the exterior of enclosure 29.

Depressing the "on" switch 56 activates the heater 3 0 and causes the oven assembly 20 to be heated to the preset maximum temperature. A temperature sensor 22 provided on the oven assembly 20 continuously feeds a signal associated with the temperature of the oven assembly 20 to a temperature control ler 24. So long as the temperature determined by the temperature sensor 22 is l ess than the predetermined preset temperature defined by the temperature control ler 24, additional energy continues to be put into the sys tem. When the preset predetermined temperature is reached, the temperature controller 24 maintains the oven assembly 20 at that temperature for a predetermined period of time as set by the timer 26. Solenoid 38 maintains the cover 32 of the oven assembly 20 on the barrel 21 during the heating cycle.

Should something go awry during '-he heating cycle, for example, if the temperature of the oven assembly 20 exceeds some predetermined maximum temperature of generally about 360°F thermostat contact switch 23 will open, causing the supply of AC power to the entire system to be interrupted. Furthermore, an emergency shut off switch 56 provided on the exterior of the enclosure 28 can be used by an operator to shut off the entire system for any reason.

Once the system has been shut off, either due to the completion of the heating cycle as set by the timer 26, or due to an emergency-type shut off. -.olenoid 38 acts to retain the cover 32 on oven assembly .0 until the entire system has cooled to some predetermined maximum safe temperature of generally about 90°F.

It has been^"found that it is important to cool the heat conductive container 12 containing the waste 15 therein slowly since any polyvinyl chloride, which is commonly present in medical waste, is unstable at temperatures between about 350° and 360°F. Accordingly, the system is shut off and allowed to air cool for a period sufficient to allow the polyvinly chloride to

-> become stable. For example, when a volume of 71in^J is used, air cooling is generally continued for about one- half (1/2) hour following completion of the heating cycle. After about 1/2 hour of air cooling, a small fan 90 provided under the heating cylinder is turned on. Use of the fan accelerates the cooling process so that the entire process is commercially viable while minimizing the flow of unacceptable odors due to instability of the polyvinyl chloride. Assuming that the system has been shut off due to completion of the heating cycle, the container 12 can be disposed of as sterile waste. Whether the container 12 has been subjected to sufficient heat to permit disposal as sterile waste can, of course be determined by observing the color of the heat sensitive strip 40.

The disclosed apparatus and process are useful for providing safe, efficient, economical and sterile disposal of hazardous medical waste. While one presently preferred embodiment of the apparatus is disclosed in detail-, it will be appreciated that the invention is not limited thereto. For example, individual oven assemblies designed to melt limited amounts of hazardous medical waste per assembly could be provided. As another alternative, a means for applying pressure can be provided for compacting the medical waste prior to, during or after the melting process.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in carrying out the above method and in the constructions set forth without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shal 1 be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Claims

WHAT IS CLAIMED IS:

1. An apparatus f or preparing haz ardous medical waste for sterile disposal comprising: a heat conductive container adapted to contain hazardous medical waste to be prepared for disposal therein; and means for applying heat to the heat conductive container in an amount suff icient to steril ize and render unusable the hazardous medical waste.

2. The apparatus of claim 1 wherein the heat conductive container is constructed of a material selected from the group consisting of metal , metal al loy, glass, ceramic and high temperature resistant plastic.

3. The apparatus of claim 1 wherein the heat conductive container has an opening so that the hazardous medical waste can be placed therein and wherein the container further includes a lid which can be positioned on the container to close the opening and form a container and lid assembly.

4. The apparatus of c l aim 3 wherein the container further includes means for sealing the lid to the container.

5. The apparatus of c l aim 4 wherein the sealing means is a mel table material provided between the container and the lid and adapted to be melted to fuse the container and the lid when heat is applied to the container.

6. The apparatus of claim 5 wherein the meltable material is solder.

7. The apparatus of claim 3 wherein the lid has an upper surface and the container has a lower surface and wherein the upper surface of the lid and the lower surface of the container are cooperatively beveled so that multiple container and lid assemblies can be stacked for storage purposes.

8. The apparatus of claim 1 wherein the container includes a heat sensitive strip which changes color at a specified predetermined temperature provided on an outside surface of the container.

9. The apparatus of claim 8 wherein the specified predetermined temperature is greater than about 340°F.

10. The apparatus of claim 1 wherein the means for applying heat achieves a temperature between about 340° and 360°F.

11. The apparatus of claim 1 wherein the means for applying heat includes an oven assembly adapted to contain the heat conductive container therein.

12. The apparatus of claim 11 wherein the oven assembly includes a barrel for containing the heat conductive container and a cover for covering the barrel.

13. The apparatus of claim 12 wherein the oven assembly further includes a heater for supplying heat to the barrel.

14. The apparatus of claim 11 wherein the oven assembly includes a temperature sensor for sensing the temperature of the oven assembly and generating a signal in proportion to the temperature sensed.

15. The apparatus of claim 14 wherein the oven assembly further includes a temperature controller that receives the signal generated by the temperature sensor and compares the signal to a preset desired temperature in order to maintain the temperature of the oven assembly at the preset desired temperature by a feedback process.

16. The appartus of claim 15 wherein the preset desired temperature is between about 340° and 360°F.

17. The apparatus of claim 1 wherein the means for applying heat includes a timer for regulating the amount of time during which heat is applied.

18. The apparatus of claim 17 wherein the timer also regulates the amount of time required to cool the heat conductive container to a temperature less than about 90°F.

19. The apparatus of claim 14 wherein the oven assembly further includes a printed circuit board that receives the signal generated by the temperature sensor and compares the signal to a preset desired temperature in order to maintain the temperature of the oven assembly at the preset desired temperature by a feedback process and that regulates the amount of time during which heat is applied.

20. The apparatus of claim 12 wherein the oven assembly includes a safety interlock system.

21. The apparatus of claim 20 wherein the safety interlock system prevents application of heat to the heat conductive container if the cover is not on the barrel of the oven assembly.

22. The apparatus of claim 20 wherin the safety interlock system prevents removal of the cover from the barrel of the oven assembly if the temperature of the oven assembly is above a predetermined maximum safe temperature.

23. The apparatus of claim 22 wherein the predetermined maximum-safe temperature is about 90°F.

24. The apparatus of claim 20 wherein the safety interlock system prevents application of heat to the heat conductive container if the temperature of the oven assembly exceeds a predetermined maximum safe temperature. 25. The apparatus^' of claim 24 wherein the predetermined maximum safe temperature is about 360°F.

26. The apparatus of claim 11 wherein the oven assembly is thermally insulated.

27. The apparatus of claim 11 wherein the oven assembly is housed in a housing having an exterior surface and wherein at least one information readout is provided on the exterior surface of the housing.

28. A process for preparing hazardous medical waste for sterile disposal comprising: providing a heat conductive container adapted to contain the hazardous medical waste to be prepared for sterile disposal therein; placing the hazardous medical waste into the heat conductive container; applying heat to the heat conductive container so that the heat conductive container acheives a temperature of between about 340° and 360°F for a first predetermined period of time sufficient to sterilize and render unusable all hazardous medical waste; allowing the heate conductive container to air cool for a second predetermined period of time; and, thereafter accelerating the cooling of the heat conductive container by directing a fan at the container to obtain sterile waste. 29. The process of -claim 28 wherein the heat conductive container has an opening so that the hazardous medical waste can be placed therein and a lid which can be positioned on the container to close the opening and wherein the process further includes placing the hazardous medical waste syringe into the heat conductive container through the opening and positioning the lid on the container to close the opening.

30. The process of claim 29 therein the container further includes means for sealing the lid to the container and wherein the process further includes sealing the lid to the container using the sealing means.

31. The process of claim 30 wherein the sealing means is a meltable material provided between the container and the lid and wherein the process further includes melting the meltable material so as to fuse the container to the lid when heat is applied to the container.

32. The process of claim 30 wherein the sealing means is solder provided between the container and the lid and wherein the process further includes soldering the container to the lid by melting the solder when heat is applied to the container.

33. The process of claim 28 wherein the container further includes a heat sensitive strip which changes color at a specified predetermined temperature provided on the outside of the container and wherein the process further includes observing a change in color of the heat sensitive strip.

34. The process of claim 28 wherein the heat conductive container is contained in an oven assembly and wherein the oven assembly includes means for maintaining the temperature of the oven assembly at a preset desired temperature and means for regulating the amount of time during which heat is applied and wherein the process further includes maintaining the temperature of the oven assembly at a preset desired temperature and regulating the amount of time during which the preset desired temperature is maintained.

35. The process of claim 34 wherein the means for regulating the amount of time during which heat is applied is also useful for regulating the amount of time required to cool the heat conductive container to a temperature less than about 90°C. and wherein the process further includes regulating the amount of time required to cool the heat conductive container to a temperature less than about 90°C.

36. The process of claim 28 wherein the heat conductive container is contained in a barrel of an oven assembly and wherein the barrel has a cover for covering the barrel and wherein the oven assembly further includes a safety interlock system which prevents application of heat to the heat conductive container if the cover is not on the barrel of the oven assembly and wherein the process further includes placing the barrel. cover on the barrel of the oven assembly so that-heat can be applied to the heat conductive container.

37. A process for preparing hazardous medical waste including plastic material and non-plastic material for sterile disposal comprising: providing a heat conductive container adapted to contain the hazardous medical waste to be prepared for sterile disposal therein; placing the hazardous medical waste into the heat conductive container; and, applying heat to the heat conductive container in an amount sufficient to melt the plastic material contained in the waste and cause the plastic material to mix with the non-plastic material in a mass and render the mass sterile.

AMENDED CLAIMS

[received by the International Bureau on 21 May 1993 ⁽21.05.93⁾ ; original claims 28, 34 and 36 amended; new claims 38-41 added; other claims unchanged (5 pages) ]

25. The apparatus of claim 24 wherein the predetermined maximum safe temperature is about 360°F.

26. The apparatus of claim 11 wherein the oven assembly is thermally insulated.

28. A process for preparing hazardous medical waste for sterile disposal comprising: providing a heat conductive container adapted to contain the hazardous medical waste to be prepared for sterile disposal therein; placing the hazardous medical waste into the heat conductive container; applying heat to the heat conductive container s o that the heat conductive container achieves a temperature of between about 340° and 360°F for a first predetermined period of time sufficient to sterilize and render unusable all hazardous medical waste; allowing the heat conductive container to cool for a second predetermined period of time sufficient to allow the waste to become stable; and, directing a fan, at the heat conductive container containing the stable waste to accelerate the cooling and yield sterile waste.

29. The process of claim 28 wherein the heat conductive container has an opening so that the hazardous medical waste can be placed therein and a lid which can be positioned on the container to close the opening and wherein the process further includes placing the hazardous medical waste syringe into the heat conductive container through the opening and positioning the lid on the container to close the opening.

30. The process of claim 29 therein the container further includes means for sealing the lid to the container and wherein the process further includes sealing the lid to the container using the sealing means .

34. The process of claim 28 wherein the heat conductive container containing the hazardous medical waste is placed in an oven assembly and wherein the oven assembly includes means for maintaining the temperature of the oven assembly at a preset temperature and means for regulating the amount of time during which heat is applied and wherein the process further includes maintaining the temperature of the oven assembly at the preset temperature and regulating the amount of time during which the preset temperature is maintained.

36. The process of claim 28 wherein the heat conductive container is placed in an oven assembly and wherein the oven assembly has a cover and wherein the oven assembly further includes a safety interlock system which prevents application of heat to the heat conductive container if the cover is not on the oven assembly and wherein the process further includes placing the cover on the oven assembly so that heat can be applied to the heat conductive container.

37. A process for preparing hazardous medical waste including plastic material and non-plastic material for sterile disposal comprising: providing a heat conductive container adapted to contain the hazardous medical waste to be prepared for sterile disposal therein; placing the hazardous medical waste into the heat conductive container; and, applying heat to the heat conductive container in an amount sufficient to melt the plastic material contained in the waste and cause the plastic material to ix with the non-plastic material in a mass and render the mass sterile.

38. The process of c l aim 37 wherein the process further includes the step of fitting a l id on the heat conductive container containing the hazardous medical waste prior to applying heat to the container.

39. The proces s of cl aim 37 wherein the process is carried out at normal pressure.

40. The proces s of cl aim 38 wherein the process is carried out at normal pressure.

41. A process of preparing hazardous medical waste including plastic and non-plastic material for sterile disposal consisting essentially of : providing a heat conductive container adapted to contain the hazardous medical waste to be prepared for sterile disposal therein; placing the hazardous medical waste into the heat conductive container; and, applying heat to the heat conductive container in an amount sufficient to mel t the plastic material contained in the waste and cause the plastic material to ix with the non-plastic material in a mass and render the mass sterile.