Patent Publication Number: US-6217835-B1

Title: Sterilization container

Description:
RELATED APPLICATION 
     This application is a continuation-in-part of Ser. No. 09/052,191, filed Mar. 31, 1998, now U.S. Pat. No. 6,048,503. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a sterilization container. It relates more particularly to a container for medical instruments and other articles which are to be sterilized by exposure to steam. 
     Prior to their use, medical and surgical instruments have to be sterilized. This is often done by placing the instruments in a container and inserting the container into an autoclave where the container and its contents are subjected to high temperature steam under pressure. The container is designed to allow steam to enter the container during the sterilization process so that the steam contacts the instruments therein. In some cases, the container is equipped with a valve which opens under the pressure of the steam in the autoclave and which closes following the sterilization process so that the container remains sealed until it is time to use the instruments. Other sterilization containers have permanent vent openings which are covered by a microbial filter. The filter allows steam to enter the container during the sterilization process but has a sufficiently fine structure to prevent the entry of microbes and other contaminants during and after sterilization. The present container is of the latter type. 
     2. Prior Art 
     Conventional sterilization containers which incorporate a microbial filter have several disadvantages. Some do not provide enough open space within the container to allow steam to penetrate, and circulate within, the container. Therefore, the sterilization cycle for such containers is relatively long, particularly if the sterilizer or autoclave does not include a vacuum cycle wherein air is drawn from the container prior to the injection of steam into the container. This problem can be alleviated to some extent by including vent openings in more than one wall of the container. However, this solution requires the placement in the container of a corresponding number of filter sheets which increases cost and the time it takes to assemble the container. Other sterilization containers are made of metal and therefore conduct heat efficiently. However, they are heavy and expensive and the heat-sterilized container cannot be handled until after it is cooled off which effectively increases the length of the sterilization cycle. 
     There do exist sterilization containers made of plastic material. However, those containers are not entirely satisfactory because it has been found that moisture accumulates within the container which moisture tends to wet the filter sheet thereby degrading its effectiveness as a microbial filter. In other such containers, the filter sheet is not sufficiently protected from medical instruments and other components within the container with the result that the sheet is penetrated, again destroying its effectiveness as a filter. 
     Still further, some prior containers of this general type are not designed to facilitate loading the container with medical instruments in a given order before sterilization so that those instruments will remain in the same position during sterilization and subsequent handling so that when it is time to use the instruments, they can be presented to a surgeon in a desired order for a particular procedure. 
     Finally, with prior sterilization containers of this general type, one cannot be assured that a sterilized container has remained unopened such that the instruments in the container are still in a sterile condition when it is time to use the instruments. 
     SUMMARY OF THE INVENTION 
     Accordingly it is an object of the present invention to provide an improved sterilization container. 
     Another object of the invention is to provide a container of this type which enhances the sterilization process so that sterilization can be carried out in a minimum amount of time. 
     A further object of the invention is to provide a sterilization container which prevents the accumulation of moisture within the container. 
     Yet another object of the invention is to provide a sterilization container which maintains instruments placed in the container at set positions within the container. 
     A further object of the invention is to provide a container of this type which promotes the circulation of steam within the container during the sterilization process. 
     Another object of the invention is to provide such a container whose microbial filter is protected against penetration by instruments and other objects within the container. 
     An additional object is to provide a sterilization container with an improved latching mechanism. 
     A further object of the invention is to provide a security lock for a container of this type which signals when the container has been unlatched improperly. 
     Other objects will, in part, be obvious and will, in part, appear hereinafter. The invention accordingly comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the following detailed description, and the scope of the invention will be indicated in the claims. 
     Briefly, our container includes an open top box-like receptacle having a bottom wall formed with an array of vent openings. A filter sheet is positioned in the receptacle so as to overly the bottom wall and the vent openings therein. Also positioned in the receptacle above the filter sheet is a highly thermally conductive plate having a multiplicity of holes therein which are smaller than the vent openings such that the plate permits the passage of steam into the receptacle space above the plate but prevents objects in the receptacle from contacting the fiber sheet. 
     The container also includes one or more instrument-supporting trays positioned in the receptacle above the plate. The trays are formed as grids with relatively large through-holes or openings. Those trays are stacked in the receptacle so that their openings are in register whereby a relatively large amount of open space remains in the receptacle, In addition, the container includes a cover which may be closed over the open top of the receptacle to provide a seal between the two, with portions of the trays contacting the underside of the cover so that when the cover is closed, there can be no appreciable vertical movements of the filter, plate and tray(s) within the container. 
     Preferably, the container is provided with at least one latch which can latch the cover in its closed position and a safety lock releasably attached to the receptacle and cover for preventing each latch from being unlatched without providing a visual indication that such unlatching has occurred. Thus, medical personnel can take an already sterilized container off the shelf and, by observing the safety lock, determine that the container has been opened after sterilization such that the contents of the container are no longer in a sterile condition. 
     Further as will be described, the interior components of the container are designed to promote efficient and thorough circulation of steam within the container during sterilization and to facilitate proper presentation of instruments that were sterilized in the container when it is time to use those instruments. Specifically, during sterilization, the thermally conductive plate functions as a heat source which re-vaporizes condensate dropping into the plate from the trays and instruments thereon thereby enhancing the sterilization process and preventing the condensate from wetting the filter sheet. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which: 
     FIG. 1 is a perspective view from above of a sterilization container incorporating the invention shown in its closed condition; 
     FIG. 2 is a perspective view from below thereof; 
     FIG. 3 is an exploded perspective view showing the interior components of the open container in greater detail; 
     FIG. 4 is a sectional view taken along line  4 — 4  of FIG. 1; 
     FIG. 5 is a fragmentary sectional view on a larger scale showing a portion of the assembled container in greater detail; 
     FIG. 6 is a view similar to FIG. 1 showing another container embodiment; 
     FIGS. 6A and 6B are sectional views showing the operation of the latch mechanism on the FIG. 6 container, and 
     FIG. 7 is a plan view of a lock for the FIG. 1 container. 
    
    
     DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     Referring to FIGS. 1 and 2 of the drawings, our container comprises a housing indicated generally at  10  made of a rugged, impact resistant, medical grade; transparent plastic material. The housing is composed of a generally rectangular receptacle  12  having a bottom wall  12   a,  a front wall  12   b,  a rear wall  12   c  and a pair of mirror-image end walls  12   d  all extending up from the bottom wall  12   a  to form an open top box-like structure. As beset seen in FIG. 2, an array of vent openings  16 , each being about ⅗in. in diameter, is provided in bottom wall  12   a,  these openings being distributed in columns and rows over substantially the entire area of the bottom wall. Also, pairs of front and rear legs  18  extend down from the bottom wall adjacent opposite ends of receptacle  12 , each pair of legs being connected by a depending rib  22  which is specially curved as will be described in more detail later. 
     Housing  10  is provided with a rectilinear cover  24  which is shaped and arranged to close the open top of receptacle  12 . Cover  24  includes a top wall  24   a,  a front wall  24   b,  a rear wall  24   c  and a pair of mirror image end walls  24   d.  As best seen in FIG. 1, the cover is preferably transparent so that one can see into the housing and its top wall  24   a  is provided with an array of dimples  26  arranged in columns and rows over the area of top wall  24   a.    
     Cover  24  is hinged to receptacle  12  by hinges  28  at the rear walls  12   c,    24   c  of those members so that the cover can be swung between a closed position shown in FIGS. 1 and 2 wherein the cover completely closes the open top of receptacle  12  and an open position shown in FIG. 3 wherein the cover is swung rearwardly so as to expose the interior of receptacle  12 . 
     As best seen in FIGS. 2 and 4, each hinge  28  includes a pivot extending from the rear wall  12   c  of receptacle  12  comprised of a pair of laterally spaced-apart ears  32  which are connected by an axle  34  and a hook  36  formed integrally with the cover rear wall  24   c  and arranged to hook around axle  34  as shown in FIG.  4 . Each hinge  28  is designed so that its hook  36  can be engaged or disengaged from the corresponding axle  34  only when the cover  24  is swung open more than 180° to the position shown in phantom in FIG.  4 . This arrangement assures that the cover  24  will remain attached to receptacle  12  under normal operating conditions for the container, e.g., as when closed or placed open on a horizontal surface for example, but still allows easy assembly and replacement of the cover. 
     As shown in FIG. 4, the upper edge or lip of receptacle  12  is somewhat rounded and the lower edge of cover  24  is grooved to receive an O-ring  38  which extends all around the cover. Thus, when the cover is in its closed position shown in FIG. 4, the O-ring provides a fluid-tight seal at the boundary between the cover and the receptacle  12 . 
     As best seen in FIGS. 1 and 4, cover  24  may be releasably locked in its closed position by a pair of laterally spaced-apart, collinear, mirror-image latches  42  on the front of housing  10  near the opposite ends thereof. Each latch  42  comprises an actuator  44  slidably mounted to the front wall  24   b  of cover  24 . When an actuator  44  is slid toward the corresponding end of housing  10 , it engages under a ramp-like detent  46  (FIG. 3) projecting from the front wall  12   b  of receptacle  12  thereby wedging the O-ring  38  against the rim of receptacle  12 , creating a seal all around the housing. On the other hand, when the two actuators  44  are moved toward one another, they disengage from their respective detents  46  allowing the cover  24  to be swung open to the position shown in FIG.  3 . 
     Referring to FIG. 1, after our sterilization container and its contents have been sterilized, it is essential to know that housing  10  has not been opened up to the time the instruments therein are to be used. Therefore, the present housing includes a safety lock shown generally at  62  removably positioned between the latch actuators  44 . The safety lock is basically an elongated, rigid plastic strip  64  having tables  64   a  extending from its opposite ends. The length of strip  64  substantially is the same as the distance between actuators  44  when those actuators are in their latching positions. 
     When the strip  64  is placed between the actuators, the tables  64   a  snap into place under the adjacent actuators thereby securing the strip to the housing  10  so that the actuators  44  cannot be moved to their unlatching positions. The ends of strip  64  are flush with latch actuators  44  and the surface of the strip is nested against the front of housing  10  and is smooth except for a pair of finger holes  66  present near the opposite ends of the strip. Absent these holds  66 , it would be very difficult to remove strip  64  without using a special tool. 
     In accordance with the invention, when a safety lock  62  is installed on housing  10 , a patch  68  of paper or other tearable material is adhered to the rear of strip  64  so as to cover the holes  66 . Resultantly, once the strip is snapped into place between the latch actuators  44 , the strip cannot be removed using one&#39;s fingers without punching a hole in at least one of the patches  68 . Therefore, when it is time to use the instruments in the sterilization container, the fact that the patches  68  are intact is a good indication that the container has not been opened previously and that its contents are still sterile. 
     Referring again to FIGS. 1 and 2, housing  10  is designed so that it can be positioned stabily in a stack of similar housings. For this, the legs  18  of receptacle  12  and the dimples  26  on cover  24  are positioned relatively so that when two housings  10  are located one over the other, the legs  18  of the upper container are aligned with selected ones of the dimples  26  of the underlying container. Preferably, legs  18  have beveled ends  18   a  which are arranged to seat snugly in those dimples. Also, ribs  22  are bowed and curved to conform to the three dimensional curvature of the cover top wall  24   a,  all to maintain the vertical alignment of the housings. 
     Refer now to FIGS. 3 and 4, our sterilization container also has an assembly inside housing  10  which includes a rectangular microbial filter sheet  72  which is shaped and arranged to cover the bottom wall  12   a  of receptacle  12  including all of the vent openings  16  therein. Preferably, the receptacle bottom wall  12   a  is provided with an array of raised pads or standoffs  74  interleaved between the vent openings  16  therein in order to space sheet  72  above openings  16  so that steam can flow through substantially the entire area of sheet  72  rather than through only the portions of the sheet directly opposite openings  16 . This assures that steam will flow into the housing  10  in a minimum amount of time. 
     Positioned above sheet  72  is a rectangular metal plate  76  formed with a multiplicity of through-holes  78  distributed in columns and rows over the entire area of the plate. Also, extending around the perimeter of the plate is a frame  82  which may be of rubber or other resilient material molded onto the edge margin of the plate. As best seen in FIG. 5, the frame  82  is formed with a depending, outwardly flaring, fin-like skirt  82   a.  When plate  76  is positioned in receptacle  12  as shown in FIGS. 4 and 5, the skirt  82   a  presses against the edge margin of filter sheet  72  and against the bottom wall  12   a  of section  12  providing a seal between frame  82  and bottom wall  12   a.  Frame  82  also spaces the plate  76  slightly above the filter sheet  72  as shown. 
     The holes  78  in the plate  76  should be small enough, e.g., {fraction (1/16)} in., so that instruments falling onto the plate will not poke through the holes  78  and puncture the filter sheet  72 . Their size and distribution should be such that the holes occupy 40-50% of the total area of the plate. 
     Referring to FIGS. 3 and 4, positioned above metal plate  76  is a lower tray shown generally at  92 . Tray  92  consists of a rigid rectangular grid  94 , molded of a suitable medical grade plastic material. Grid  94  is formed with columns and rows of relatively large, e.g., 1 in. 2 , square openings or through-holes  96  which are distributed over the entire area of the grid. For reasons to be described later, the walls of each opening  96  are tapered so that the opening is larger at the top of grid  94  than at the bottom thereof. 
     Tray  92  also includes a pair of inverted, U-shaped handles  98  which extend up from grid  94  at the opposite ends thereof. The handles may be secured to grid  94  by suitable fasteners (not shown). Alternatively, the arms of each handle may be molded as tubes integral with grid  94  with the bridging portion of each handle being formed as a separate member with down-turned ends which may be press fit into the ends of those molded tubes. Also extending up from grid  94  is a plurality, herein four, posts  102 . Posts  102  are arranged in pairs at opposite ends of grid  94  inboard handles  98 . The end segment of each post  102  has a reduced diameter thereby forming a shoulder  102   a  more or less midway up along the post. Shoulders  98   a  are also provided on the arms of handles  98 . The shoulders  98   a  and  102   a  collectively define a plane spaced above and parallel to grid  94 . 
     Still referring to FIG. 3, the final component of the container is an upper tray shown generally at  110 . Tray  110  comprises a rectangular, molded plastic grid  112  which is similar to grid  94  except that it is slightly shorter than grid  94 . Like grid  94 , it is provided with an array of large square openings  114  with tapered sidewalls. The front and rear edges of grid  112  are provided with laterally spaced-apart notches  116  which, when grid  112  is positioned directly over plate  94 , are aligned with posts  102  so that tray  110  can be set down on tray  92  such that grid  112  is supported on the shoulders  98   a  and  102   a  of tray  92 . 
     The upper tray  110  also includes a pair of handles  118  similar to handles  98  on tray  92 . In this case, however, the handles are mounted at the front and rear edges of grid  112 . 
     To assemble the illustrated container, an appropriately dimensioned filter sheet  72  is set into receptacle  12  so as to cover the bottom wall  12   a.  As noted previously, the filter is spaced slightly above the bottom wall by the pads  74  so that substantially the entire undersurface of the filter is accessible through the vent openings  16  in the bottom wall  12   a.  Then, the perforate metal plate  76  is set into receptacle  12  so that its frame  82 , or more particularly the frame skirt  82   a,  contacts and presses down on the edge margin of the filter sheet as shown in FIG.  5 . As seen there, the plate  76  is spaced slightly above the filter  72 . Then, the lower tray  92  is placed in receptacle  12 , the edge margin of that tray resting on frame  82 . Finally, the upper tray  110  is placed in position on the shoulders  98   a  and  102   a  of tray  92 . As noted previously, grid  112  is shorter than tray  92  so that it fits between the handles  98  of the latter tray. In this position, the two trays are spaced parallel one above the other with their openings  96  and  114  being in vertical alignment so that there is a considerable amount of open space in the receptacle  12 . 
     It is important to note that the heights of the posts  102  and the tray handles  98  and  118  are such that when cover  24  is closed as shown in FIG. 4, those posts and handles extend all the way up to the underside of the cover  24 . That fact coupled with the previously mentioned resilient skirt  82   a  on the plate frame  82  ensures that the components of the container inside housing  12  have essentially no vertical play when the cover  24  is closed. 
     In order to fix the positions of medical instruments on trays  92  and  110 , part or all of the grates of either or both trays may be covered by a finger mat  122 , a fragment of which is shown on tray  110  in FIG.  3 . Preferably, the mat has openings  123  which register with the openings in the underlying grate. Finger mats are well known from U.S. Pat. No. 5,540,901, for example. The mat may have fingers of various heights so the mat can hold instruments of various sizes. For example, the fingers may be shorter near the edges of the mat. 
     The positions of the medical instruments can also be fixed by means of brackets or fixtures which are arranged to plug into one or more of the openings  96  and  114  in either or both of trays  92  and  110 . For example, FIG. 3 illustrates two such fixtures adapted to be plugged into tray  92 . One fixture consists of a post  124  having a base  126  with a pair of spaced-apart depending legs  126   a.  The spacing of the outer walls of the two legs corresponds the dimensions of the openings  96  and  114  in trays  92  and  110  so that the base  26  can be plugged into any one of those openings. As noted previously, the walls of those openings are tapered so that if the post is pressed down into an opening, the legs  126   a  of its base are squeezed together thereby resiliently retaining the post to the tray. 
     FIG. 3 also illustrates a channel-type fixture  132  having pairs of depending legs  132   a  spaced along its length. The channel may be releasably connected to tray  92  (or tray  110 ) by pressing the pairs of legs into adjacent tray openings. Various other instrument-retaining brackets and fixtures may be provided with legs which plug into one or both of trays  92  and  110 . Examples of such fixtures and their uses are disclosed in the above-identified patent and in copending application Ser. No. 08/807,812, filed Feb. 26, 1997, the contents of which are incorporated herein by reference. 
     After the trays  92  and  110  carrying the various instruments to be sterilized are positioned in the receptacle  12 , the cover  24  may be closed and latched by moving the latch actuators  42  laterally toward the ends of the container. This seals the cover to receptacle  12  so that the only fluid entry into housing  10  is through the vent opening  16 . Then, the safety lock  62  with its finger holes  66  covered by patches  68  may be snapped into place between the two actuators  44 . The locked and sealed container may now be placed in a steam autoclave. During autoclaving, steam enters the container through the vent openings  16  in receptacle bottom wall  12   a  and is free to pass through substantially the entire area of filter  72  which, as noted previously, is fine enough to exclude microbes and the like. The steam then flows through the holes  78  in the metal plate  76  and through the large openings in the two trays  92  and  110  and circulates around and over the trays so that the steam is rapidly brought into contact with the instruments reposing on the trays. Due to the aforesaid construction of the two trays, the interior of the closed container is quite open so that steam is free to circulate throughout the interior of the container with the result that the instruments are thoroughly sterilized in a minimum amount of time. 
     If condensation does occur within the container, the resulting condensate is free to drip down onto plate  76  which becomes quite hot during the sterilization process. Resultantly, the plate  76  functions as a heat source which re-evaporates the condensate thus further contributing to the sterilizing of the instruments in the container. In addition, the heated metal plate minimizes the accumulation of moisture at the bottom of receptacle  12  which moisture could wet the filter sheet  72  thus degrading its effectiveness as a microbial filter. In other words, if filter sheet  72  should become overly wet, microbes are more apt to penetrate the filter and the filter itself may become a site for bacterial growth. 
     At the end of the sterilization cycle, the steam is turned off and the container is exposed to atmospheric pressure while remaining in the autoclave. With this, the radiant heat from the walls of the autoclave penetrates the container and evaporates substantially all of the residual moisture in the container. As a result, assuming the container is not opened, the container contents can remain in a sterilized condition on the shelf for as long as six months or more. When it does become time to use the instruments in the container, it is readily apparent from the condition of safety lock  62  whether or not the container has already been opened so that the container contents are not longer sterile. In other words, if one or both of the patches  68  on lock  62  have been penetrated, that is a good indication that someone has removed and then replaced the lock. This raises the possibility that the container cover  24  has been opened so that the container contents are no longer sterile. 
     The sterilization container described herein also serves as a convenient means for presenting the instruments that were sterilized in the container. More particularly, the container can be carried to the operating room, clinic or the like and opened after removing the safety lock  62 . The trays  92  and  110  can then be removed either together or separately from the receptacle  12  and be placed on a suitable support surface adjacent the patient. The various instruments on the trays are in their original positions due to their aforesaid retention by mat  122  or fixtures  124 ,  132  so that they may be presented in the order of use for a particular procedure. After the instruments have been used, they may be placed in the receptacle  12  which may then be closed by cover  24  so that there is no danger of those used instruments causing contamination as they are being brought to a disposal or cleaning site. 
     Refer now to FIG. 6 which illustrates a sterilization container with a slightly different latch and safety lock. This container includes a housing shown generally at  150  composed of a rectangular receptacle  152  having a front wall  152   a  and a cover  154  having a front wall  154   a  hinged to receptacle  152  in the same manner as the housing discussed above in connection with FIG. 1. A single long latch  156  shaped more or less like a razor clam valve is movably connected to the receptacle front wall  152   a  by a pair of identical links  158 . One end of each link  158  is connected by a pivot pin  162  to a pair of ears  164  projecting from the receptacle front wall  152   a.  The other end of each link  158  is connected by a second pivot pin  166  to a pair of bosses  168  extending from the rear or lower edge  156   a  of latch  156  at the interior of the latch. Also, latch  156  is formed with a pair of interior noses  172  located at the front or upper edge  156   b  of latch  156  directly opposite each pair of ears  168 . There is also a rounded notch or recess  174  formed in the latch edge  156   b  to facilitate opening the latch as will be described. 
     Also present on the receptacle front wall  152   a  is a generally rectangular protrusion or boss  176  containing a vertical slot  178  for reasons that will be described later. 
     The housing cover  154  is formed with two pairs of laterally spaced-apart keepers or detents  182  which project from the cover front wall  154   a  above the pair of ears  164  in receptacle  152 . In addition, a generally rectangular boss  184  with a vertical slot  186  projects from the cover front wall  154   a  between the pairs of keepers  182 . When cover  154  is closed on receptacle  152 , the cover boss  184  is located directly above the receptacle boss  176  so that the slots  178  and  186  are in vertical alignment. 
     Refer now to FIGS. 6A and 6B, in order to latch and lock housing  150 , the cover  154  is swung to its closed position on receptacle  152  as shown in FIG.  6 A and the latch  156  is swung up on links  158  so that the noses  172  at the upper edge  156   b  of the latch engage over keepers  182  projecting from the front wall  154   a  of receptacle  154  as shown in FIG.  6 A. Then, latch  156  is pushed down to the position shown in FIG.  6 B. The lengths of the links  158  is such that when the latch is pressed down as aforesaid, links  158  are swung to an over center position which maintains the latch in a stable latched position as illustrated in FIG.  6 B. 
     In order to release the latch  156 , the user engages the lower edge of the latch at recess  174  with a finger and lifts that lower edge away from receptacle  152 . This swings the links  158  outward to the position shown in FIG. 6A allowing the latch noses  172  to be disengaged from the keepers  182  on the cover by swinging out the upper edge  156   b  of the latch away from cover  154  so that the cover can be opened. 
     As with the FIG. 1 sterilization container, it is sometimes essential to know whether or not housing  150  has been opened after having been sterilized. Therefore, housing  150  includes a safety lock shown generally at  190  in FIG.  7 . The safety lock is basically a generally rectangular tearable paper or plastic strip whose nominal width is slightly less than the widths of slots  178  and  186  in housing  150 . Lock  190  includes a main panel  192  formed with a pair of laterally extending side tabs  194  midway along its length. An area of panel  192  below tables  194  is available to receive printed information and may carry a sterilization indicator  196  which may be a chemically treated spot which changes color when exposed to high temperature steam. Above tabs  194 , the panel  192  is joined at a perforated tear line  198  to a smaller auxiliary panel  202 . Panel  192  also contains a generally U-shaped cut line  204  that defines a tab  206  connected to panel  192  only at the bottom edge margin of that panel. In addition, an adhesive  208  is applied to the front surface of auxiliary panel  202  or the back surface of panel  192  (or both). 
     Safety lock  190  may be installed on housing  150  when the housing is in its partially latched condition shown in FIG.  6 A. For this, the lock panel  202  is inserted down through the vertically aligned slots  178  and  186  behind latch  156  with the adhesive  208  side of the panel facing the housing as shown in phantom in FIG. 6A until tabs  194  engage the top of cover boss  184 . Then, after latch  156  is swung down to its latched position shown in FIG. 6B, the panel  202  is folded up in front of the latch and the free end of panel  192  is folded down over latch over panel  202  so that the two panels are adhered. together by adhesive  208  as shown in FIG.  6 B. The adhesive  208  may be a water soluble adhesive or a contact adhesive which requires a similar adhesive area on the underside of panel  92 , i.e., like some mailing envelopes. 
     When lock  190  encircles latch  156  as shown in FIG. 6B, the latch cannot be swung up to its partially open position shown in FIG. 6A without tearing the lock along the tear line  198  which is located right at the lower edge of the latch as shown in FIG.  6 B. 
     On the other hand, if someone should try to peel the adhered panel  192  from panel  198  in an attempt to defeat the lock, the tab  206  would be torn from the remainder of panel  192  so that it would be readily apparent that the lock has been tampered with and that housing  150  may have been opened so that the interior of the housing and its contents may no longer be in a sterile condition. 
     The housing  150  depicted in FIG. 6 is particularly advantaged in that it has only a single latch which must be manipulated in order to open and latch the housing and its safety lock is a simple inexpensive paper part. Of course, the FIG. 6 housing also has all of the advantages of the one depicted in FIG.  1 . 
     It is apparent from the foregoing that our sterilization container greatly facilitates the sterilizing of medical instruments by enabling the sterilization process to be carried out with maximum speed and efficiency. Yet, the container is for the most part made of a minimum number of plastic parts which can be molded in quantity at relatively low cost. Therefore, the container should find wide acceptance in hospitals and clinics where instruments have to be sterilized on a daily basis. 
     It will thus be seen that the objects set forth, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above description without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall 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 described herein.