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Title:
SELF-DISINFECTING WATER TRAP
Document Type and Number:
WIPO Patent Application WO/2019/197137
Kind Code:
A1
Abstract:
The present invention relates to a self-disinfecting water trap for use in a washbasin having a drain comprising a housing having a top part and a bottom part defining an interior space adapted for maintaining trapped water.

Inventors:
TERKELSEN, Jørn (Sandbjergvej 11, 2970 Hørsholm, 2970, DK)
Application Number:
EP2019/057214
Publication Date:
October 17, 2019
Filing Date:
March 22, 2019
Export Citation:
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Assignee:
DOLPHIN CARE APS (Sandbjergvej 11, 2970 Hørsholm, 2970, DK)
International Classes:
E03C1/126; E03C1/28
Domestic Patent References:
WO2011032543A22011-03-24
WO2007019615A12007-02-22
WO2011092544A12011-08-04
Foreign References:
EP2561893A12013-02-27
DE19813544A11999-10-07
US20040177439A12004-09-16
DE4224445A11994-01-27
DE29807712U11999-04-01
Other References:
None
Attorney, Agent or Firm:
LBKPATENT APS (Cobis Ole Maaløes Vej 3, 2200 Copenhagen, 2200, DK)
Download PDF:
Claims:
We claim:

1. A self-disinfecting water trap for use in a washbasin having a drain comprising a housing having a top part and a bottom part defining an interior space adapted for maintaining trapped water, wherein

(i) the top part has a first opening configured to engage in a liquid tight manner with the drain of the washbasin, optionally via a hollow inlet pipe, and a second opening configured to engage in a liquid tight manner with a hollow outlet pipe for discharging waste water;

(ii) the bottom part is adapted to receive and maintain an UVC light source in a liquid tight manner, wherein the UVC light source when in operation radiate the trapped water and the total interior space.

2. The self-disinfecting water trap of claim 1 wherein the UVC light source is adapted to

radiate all the trapped water and all of the interior space.

3. The self-disinfecting water trap of claim 1 or 2 comprising the hollow inlet pipe having a first end and an opposite second end both of which are open, wherein the first end extends into the interior space of the housing and is adapted to extend below the second opening of the top part, and the second end is configured to engage in a liquid tight manner with the drain of the washbasin.

4. The self-disinfecting water trap of any one of claims 1-3 comprising the hollow outlet pipe having a first end and an opposite second end both of which are open, wherein the first end extends into the second opening of the top part and the second end is adapted to discharge waste water.

5. The self-disinfecting water trap of any one of claims 1-4 comprising the UVC light source.

6. The self-disinfecting water trap of claim 5 wherein the UVC light source is adapted to

provide UVC light at 254 nm.

7. The self-disinfecting water trap of claim 6 wherein the UVC light source is one UVC lamp providing UVC light at 254 nm.

8. The self-disinfecting water trap of claim 7 wherein the UVC lamp is located centrally in the bottom part of the housing.

9. The self-disinfecting water trap of any one of claims 1-8 wherein the bottom part is adapted to receive the UVC light source through one opening configured to receive the UVC light source and maintain it in a liquid tight manner.

10. The self-disinfecting water trap of any one of claims 1-8 wherein the bottom part is adapted to receive the UVC light source through two opposite openings both configured to receive the UVC light source and maintain it in a liquid tight manner.

11. The self-disinfecting water trap of any one of claims 5-10 wherein the UVC light source is coated with a nanocover not absorbed by the UVC light.

12. The self-disinfecting water trap of any one of claims 1-11 wherein all parts of the water trap are made of metal, such as an alloy, e.g. brass, optionally chrome plated.

13. The self-disinfecting water trap of any one of claims 1-12 wherein all inner parts of the water trap are smooth to reduce formation of bio-films.

14. The self-disinfecting water trap of any one of claims 5-13 wherein all inner parts of the water trap are radiated by the UVC light source.

15. The self-disinfecting water trap of any one of claims 1-14 wherein the housing is

substantially cylinder shaped.

16. The self-disinfecting water trap of any one of claims 1-15 wherein the top and bottom parts are detachable and connectable in a liquid tight manner.

17. The self-disinfecting water trap of any one of claims 1-16 wherein the bottom part

comprises a detachable lid or plug connected in a liquid tight manner adapted to remove the trapped water.

18. A method of disinfecting water from a washbasin having a drain comprising providing the self-disinfecting water trap of any one of claims 1-17 and connecting the water trap to the drain of the washbasin and adapting the outlet pipe for discharging waste water.

19. Use of the self-disinfecting water trap of any one of claims 1-18, for reducing

microorganisms in the drain of the washbasin and in the water-trap.

20. A washbasin system having a washbasin and a drain comprising (a) a self-disinfecting water trap of any one of claims 1-18, and (b) the drain is adapted to be in liquid tight connection with the hollow inlet pipe, wherein the inlet pipe is made of a metal and has an inner surface which is smooth and which is adapted to be exposed to the UVC light from the water trap.

21. The washbasin of claim 20 wherein the drain comprises a strainer element integrated in the washbasin and adapted to receive a plug for containing water in the washbasin, wherein the strainer element has multiple openings for water to get through.

22. The washbasin of claim 21 wherein the multiple openings of the strainer are adapted to remove water efficiently from the washbasin and to reduce light from the UVC light source with at least 30%, such as at least 50%.

Description:
SELF-DISINFECTING WATER TRAP

FIELD OF THE INVENTION

The present invention relates to a self-disinfecting water trap for use in a washbasin, for instance in a hospital facility. Furthermore, the present invention is concerned with a method of disinfecting water from a washbasin, such a washbasin in a hospital facility. The present invention also relates to use of such self-disinfecting water trap. Furthermore, a washbasin system is described and claimed.

BACKGROUND OF THE INVENTION

Drains and in particular water traps in washbasins are some of the most contaminated areas in the household, and in particular in hospitals. Such water traps are seen as a serious source of contamination and in particular in hospitals is transmitting multidrug-resistant bacteria to patients.

SUMMARY OF THE INVENTION

The present inventors have realized that there is a need for improving the environment around washbasins and sinks at hospital facilities, and in particular, in hospital rooms and toilets used by patients, personnel and visitors/relatives at hospitals. Similar needs, without limitation, are present when it comes to ordinary households and public areas with wash facilities.

The present invention concerns a self-disinfecting water trap for use in a washbasin having a drain comprising a housing having a top part and a bottom part defining an interior space adapted for maintaining trapped water, wherein (i) the top part has a first opening configured to engage in a liquid tight manner with the drain of the washbasin, optionally via a hollow inlet pipe, and a second opening configured to engage in a liquid tight manner with a hollow outlet pipe for discharging waste water;

(ii) the bottom part is adapted to receive and maintain an UVC light source in a liquid tight manner, wherein the UVC light source when in operation radiate the trapped water and the total interior space.

In an embodiment the UVC light source is adapted to radiate all the trapped water and all of the interior space. In a further embodiment the self-disinfecting water trap of the present invention comprises the hollow inlet pipe having a first end and an opposite second end both of which are open, wherein the first end extends into the interior space of the housing and is adapted to extend below the second opening of the top part, and the second end is configured to engage in a liquid tight manner with the drain of the washbasin.

In a still further embodiment the self-disinfecting water trap of the present invention comprises the hollow outlet pipe having a first end and an opposite second end both of which are open, wherein the first end extends into the second opening of the top part and the second end is adapted to discharge waste water. In a further embodiment the self-disinfecting water trap of the present invention comprises the

UVC light source. Preferably, the UVC light source is adapted to provide UVC light at 254 nm.

Due to constraints it is preferred to have one UVC lamp providing UVC light at 254 nm, although 2 or 3 UVC lamps could be present. Preferably, and in order to provide the most effective source of UVC light, the UVC lamp is located centrally in the housing bottom part. In a still further embodiment the bottom part is adapted to receive the UVC light source through one opening configured to receive the UVC light source and maintain it in a liquid tight manner.

In a further embodiment the bottom part is adapted to receive the UVC light source through two opposite openings both configured to receive the UVC light source and maintain it in a liquid tight manner. In a still further embodiment the UVC light source is coated with a nanocover not absorbed by the UVC light.

In a further embodiment all parts of the water trap are made of metal, such as an alloy, e.g. brass, optionally chrome plated.

In a still further embodiment all inner parts (surfaces) of the water trap are smooth to reduce formation of bio-films.

In a further embodiment all inner parts of the water trap are radiated by the UVC light source.

In a still further embodiment the housing is substantially cylinder shaped. In a further embodiment the top and bottom parts are detachable and connectable in a liquid tight manner.

In a still further embodiment the bottom part comprises a detachable lid or plug connected in a liquid tight manner adapted to remove the trapped water. In a further aspect the present invention relates to a method of disinfecting water from a washbasin having a drain comprising providing the self-disinfecting water trap of the present invention and any one of the above embodiments and connecting the water trap to the drain of the washbasin and adapting the outlet pipe for discharging waste water.

In a still further aspect the present invention relates to use of the self-disinfecting water trap of the present invention and any one of the above embodiments, for reducing microorganisms in the drain of the washbasin and in the water-trap.

In a further aspect the present invention relates to a washbasin system having a washbasin and a drain comprising (a) a self-disinfecting water trap of the present invention and any one of the above embodiments, and (b) the drain is adapted to be in liquid tight connection with the hollow inlet pipe, wherein the inlet pipe is made of a metal, such as an alloy, and has an inner surface which is smooth and which is adapted to be exposed to the UVC light from the water trap.

In an embodiment the drain comprises a strainer element integrated in the washbasin and adapted to receive a plug for containing water in the washbasin, wherein the strainer element has multiple openings for water to get through. In a further embodiment the multiple openings of the strainer are adapted to remove water efficiently from the washbasin and to reduce light from the UVC light source with at least 30%, such as at least 50%.

Further objects and advantages of the present invention will appear from the following description, and claims. DESCRIPTION OF THE INVENTION

A study of the efficacy of ultraviolet-C (UVC) light to decontaminate water traps has been carried out in a hospital facility. This closed study shows a very clear and effective decontamination of water traps and the reduction in bacterial counts was very effective. Also, the study showed that removal of the water trap of the present invention led to quick contamination. This invention is concerned with a water trap device which is self-disinfecting and can be used in sanitarian facilities. The water trap device of the present invention efficiently removes microorganisms including bacteria due to a specific construction of the water trap in combination with the location of the UVC light source in the water trap. UVC light decontamination of water traps may be a feasible adjunctive for prevention of spread of multi-resistant water bacteria from washbasins to

immunocompromised patients.

The present invention provides these advantages with the described solution.

The present invention concerns a self-disinfecting water trap for use in a washbasin having a drain. Such as washbasin is found in domestic homes, as well as in public areas, such as rest rooms/toilets, but also in hospitals where contamination would have a great impact to all areas of the hospital.

The water trap of the present invention comprises a housing having a top part and a bottom part defining an interior space adapted for maintaining trapped water, and the top and bottom part may be in two part form or may be seen as one housing, wherein the top and bottom merely indicates which half of the housing reference is made to.

The top part has a first opening configured to engage in a liquid tight manner with the drain of the washbasin. It is clear to the skilled person that in order to make such a connection liquid tight the use of for instance a threaded connection, would be an option, although other solutions are possible. Sometimes the distance from the location of the water trap top opening and the drain of the washbasin will require a connection pipe which have a length depending on such distance. The connection pipe is a hollow inlet pipe, made of a metal, such as an alloy.

The top part also has a second opening configured to engage in a liquid tight manner with a hollow outlet pipe for discharging waste water, and typically such second opening is located in the side of the top part so as to easily connect such opening to another pipe that will lead waste water to a different location, such as a sewer.

The bottom part is adapted to receive and maintain an UVC light source in a liquid tight manner, wherein the UVC light source when in operation radiate the trapped water and the total interior space. The UVC light source is adapted to radiate all the trapped water and all of the interior space. The UVC light source is located in a defined space extending into the bottom part so that the UVC light when maintained radiates all of the interior space of the water trap including any hollow inlet pipe. Typically, the UVC light source when implemented and in use extends form an inner wall of the bottom part to the opposite inner wall of the bottom part. Preferably, the UVC light source is adapted to provide UVC light at 254 nm, since experiments have shown that outside this wavelength effectivity is reduced considerably. Due to constraints it is preferred to have one UVC lamp providing UVC light at 254 nm, although 2 or 3 UVC lamps could be present. Preferably, and in order to provide the most effective source of UVC light, the UVC lamp is located centrally in the housing bottom part. Thus, the UVC lamp is located centrally and extends across the whole distance from one inner wall to the opposite inner wall. The bottom part may be adapted to receive the UVC light source through one opening configured to receive the UVC light source and maintain it in a liquid tight manner, however, to make the water trap more user friendly and easier to adapt to different situations and locations of washbasins the bottom part is adapted to receive the UVC light source through two opposite openings both configured to receive the UVC light source and maintain it in a liquid tight manner. The UVC lamp is covered by a glass also known as a sleeve protecting the UVC source, and to further protect the glass a nanocover is applied, preferably to the full surface area of the glass.

Preferably, the UVC light source is coated with a nanocover not absorbed by the UVC light. The nanocover is used for reducing calcium deposits on the outer part of the glass defining the UVC lamp. The nanocover shuns the water and avoids binding of water to the glass surface. Thus, the calcium cannot bind to the nanocover and consequently no calcium is formed, which ensure a continued effective UVC light in the water trap. The pure glass surface without nanocover may in areas with hard water experience the formation of calcium carbonate on the glass leading to a less effective UVC radiation during extended use.

Typically, the nanocover may be made of a mixture of carbon hydrogens and silicum dioxide. Si02 is chemically bound to the glass surface. The nanocover is applied by spray although dipping and other ways of application are contemplated. The nanocover coating is applied to the sleeve glass to create an even distribution on the glass which coating is relatively thin, typically the UVC lamp is protected with a 20,5 mm closed/domed quartz sleeve which protects against air and water flow, breakage, leakage, temperature fluctuations, and environmental hazards. The UVC light form the lamp has a wavelength of 254 nm, and since the nanocover do not absorb at this wavelength it will not influence the effectivity of the UVC lamp. The optional hollow inlet pipe for use in top part first opening is made of a metal and is possible to adjust during installation under a washbasin. In order to function optimally, the first end of the hollow inlet pipe should extend into the interior space of the housing in such a way that the first end extends below the second opening of the top part, to avoid complications during use, and proper functioning of the water trap.

The second opening of the top part typically is equipped with an outlet pipe protruding from the opening to a point where the waste water can be discharged. Such second pipe may be made of any material such as plastic or metal, but when the water trap of the present invention is manufactured in metal it will be preferred to also make the inlet pipes for the top part of metal. As used herein the term“metal” means any metal as such or metal mixtures, such as alloys, typically brass is used. Optionally the metal, such as brass is then chrome plated.

The formation of bio-films may contribute to contamination in the inner space of the housing and the different parts, such as hollow inlet pipes extending from first and second openings in the top part, and it is therefore preferred to make all inner parts (surfaces) of the water trap smooth to reduce formation of bio-films.

Typically, the housing is substantially cylinder shaped. The top and bottom parts of the housing may be detachable and connectable in a liquid tight manner, or the bottom part may comprise a detachable lid or plug connected in a liquid tight manner adapted to remove the trapped water. Such lid or plug is placed at the lowest part of the bottom part, to make removal of trapped water easy and user friendly.

In a further aspect the present invention relates to a method of disinfecting water from a washbasin having a drain comprising providing the self-disinfecting water trap of the present invention and any one of the above embodiments and connecting the water trap to the drain of the washbasin and adapting the outlet pipe for discharging waste water. It is to be understood that each of the above embodiments described in connection with the self-disinfecting water trap of the present invention are also intended to be embodiments in respect of method of disinfecting water of the present invention.

In a still further aspect the present invention relates to use of the self-disinfecting water trap of the present invention and any one of the above embodiments, for reducing microorganisms in the drain of the washbasin and in the water-trap. It is to be understood that each of the above embodiments described in connection with the self-disinfecting water trap of the present invention are also intended to be embodiments in respect of the use of the self-disinfecting water trap of the present invention. In a further aspect the present invention relates to a washbasin system having a washbasin and a drain comprising (a) a self-disinfecting water trap of the present invention and any one of the above embodiments, and (b) the drain is adapted to be in liquid tight connection with the hollow inlet pipe, wherein the inlet pipe is made of a metal, such as an alloy, and has an inner surface which is smooth and which is adapted to be exposed to the UVC light from the water trap. It is to be understood that each of the above embodiments described in connection with the self-disinfecting water trap of the present invention are also intended to be embodiments in respect of the washbasin system of the present invention.

The drain typically has a strainer element integrated in the washbasin and adapted to receive a plug for containing water in the washbasin, wherein the strainer element has multiple openings for water to get through. The openings in the strainer should be sufficient to remove water from the washbasin during use and at the same time such openings should also reduce light from the UVC light source with at least 30%, such as at least 40%, at least 50%, or at least 60%.

The invention will now be described more fully with reference to the appended drawings illustrating typical embodiments of the water trap of the present invention.

These drawings are by no means limiting the scope of the present invention and are only intended to guide the skilled person for better understanding of the present invention.

Figure 1 illustrates a water trap (10) of the present invention having a top part (14) and a bottom part (16) and an interior space (not shown). The top and bottom parts constitute the housing (12). The top part (14) has a first opening (18) and a second opening (22) wherein the first opening (18) is defined by a connection element (20) which can engage with a drain of a washbasin or a connection pipe, such as a hollow inner tube (not shown), extending from the washbasin. The second opening (22) is extended by a pipe connection (24) which is equipped with a threaded inner part (26) for engaging in a liquid tight manner with an extension pipe (not shown) for leading waste water to a sewer. In the bottom part two pipe extensions (30, 34) are located opposite each other which first pipe extension (30) has an opening (28) adapted for receiving a UVC lamp. On the opposite side the other pipe extension (34) has a similar opening (not shown) adapted for receiving a UVC lamp. Thus, in this embodiment the UVC lamp may be inserted and mounted from both openings in the pipe extensions (30, 34). The small connection (32, 36) is an outlet for earth connection during use.

Figure 2 illustrates a similar water trap (40) as in figure 1 seen from the side where the second opening (44) in the top part (42) is seen. The corresponding top (42) and bottom part (46) are the same as in figure 1 (14 and 16). The top (52) of the top part (42) is located opposite the bottom (54) of the bottom part (46). In the bottom part two pipe extensions (48, 50) are located opposite each other which pipe extensions (48, 50) have openings (not shown) adapted for receiving a UVC lamp, as also described in figure 1. The small connections (56, 58) is an outlet for earth connection during use.

Figure 3 illustrates the same water trap (40) as in figure 2, and seen as the cross-section along line A-A. The top (52) has a threaded part for engaging with the drain optionally via a hollow inner pipe (not shown). The top part (42) has the extension pipe (62) with the second opening (44) and the interior space (66) is illustrated. The part (60) indicates the opening in the bottom part (46) where the UVC lamp is introduced for use during operation of the water trap, also shown in figure 2 at extension pipes (48, 50).

Figure 4 illustrates the same water trap (40) as in figure 2 and seen as the cross-section along line B-B, seen from top part to bottom part. The cylindrical interior space (66) is indicated and the bottom part (46) surrounds said inner space (66) and the openings (68, 70) in the extension pipes (48, 50) are located centrally and opposite each other. The openings are adapted to receive a UVC lamp and to maintain the UVC lamp in a liquid tight manner. The small connections (56, 58) is an outlet for earth connection during use.

Figure 5 illustrates a different shape of an embodiment of the water trap (80) having a top part (84) and a bottom part (96) and an interior space (not shown). The top and bottom parts constitute the housing (92). The top part (84) has a first opening (82) and a second opening (86) wherein the first opening (82) is defined by a connection element which can engage with a drain of a washbasin or a connection pipe extending from the washbasin. The second opening (86) is extended by a pipe connection (86) which is equipped with a threaded inner part (not shown) for engaging in a liquid tight manner with an extension pipe (not shown) for leading waste water to a sewer. In the bottom part (96) one pipe extension (94) can be seen from the end of insertion of the UVC lamp, and this one pipe extension (94) has an opening (94) adapted for receiving a UVC lamp. Thus, in this embodiment the UVC lamp may be inserted and mounted from only one opening. The top part (84) and bottom part (96) are illustrated spaced apart, in that an inner tube/pipe (88) can be seen at the assembly between top part (84) and the engaging part (90) of the bottom part (96) for securing a liquid tight housing during use. The small connection (98) is an outlet for earth connection during use.

Figure 6 illustrates the same water trap (80) as in figure 5 and seen as the cross-section along line C-C. Here the hollow inner tube or pipe (88) can be seen as extending form the top opening (102) of the top part (84) and to a location (104) below the second opening of the top part (not shown). The interior space is illustrated as (100) and in the bottom part (96) the UVC lamp (94) is shown as maintained in the bottom part (96) of the housing (92). The opposite end (104) of the opening having the inserted UVC lamp (94) extends from the side of the bottom part to house and secure and maintain the UVC lamp during use.

Figure 7 illustrates the same water trap (80) as in figure 5 and seen as the cross-section along line D-D. As can be seen the UVC lamp (94) is located centrally and extends from both sides of the bottom part of the housing securing a full UVC exposure of the interior space (100) as well as trapped water and parts of the water trap or water trap system facing the inside of the housing (92).

Figure 8 illustrates a strainer element (110) having a top part (112) and an opposite bottom part (114), wherein the bottom part is an opening for being engaged with the water trap, and the top part (112) contains several small openings (122, 124, 126) for the water from the washbasin to get out and into the water trap. The top part has an edge part (120) which is circumferential (not shown) and is adapted to fit into a drain of a washbasin. The inner space (118) defines a hollow space for water to run through when the washbasin is in use, and the strainer (110) is delimited by a wall (116) defining the tube extension from the top part and into the water trap (not shown).

Figure 9 illustrates the strainer element (110) of figure 8, seen from the top part. As illustrated in this embodiment the top part contains seven small openings (122, 124, 126, 130, 132, 134, 136) for the water from the washbasin to get out and into the water trap. The top part has an edge part

(120) which is circumferential and the circumferential inner lines (128) illustrates a small recess for leading water into the small openings (122, 124, 126, 130, 132, 134, 136).

All references, including publications, patent applications and patents, cited herein are hereby incorporated by reference to the same extent as if each reference was individually and specifically indicated to be incorporated by reference and was set forth in its entirety herein.

All headings and sub-headings are used herein for convenience only and should not be construed as limiting the invention in any way. Any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Recitation of ranges of values herein are merely intended to serve as a short method of referring individually to each separate value falling within the range, unless other- wise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. Unless otherwise stated, all exact values provided herein are representative of corresponding approximate values ( e.g ., all exact exemplary values provided with respect to a particular factor or measurement can be considered to also provide a corresponding approximate measurement, modified by "about", where appropriate).

All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.

The terms“a” and“an” and“the” and similar referents as used in the context of de-scribing the invention are to be construed to insert both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Thus,“a” and“an” and“the” may mean at least one, or one or more.

The use of any and all examples, or exemplary language (e.g.,“such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise indicated. No language in the specification should be construed as indicating any element is essential to the practice of the invention unless as much is explicitly stated.

Throughout the description when“selected from” or“selected from the group consisting of’ is used it also means all possible combinations of the stated terms, as well as each individual term.

The citation and incorporation of patent documents herein is done for convenience only and does not reflect any view of the validity, patentability and/or enforceability of such patent documents.

The description herein of any aspect or embodiment of the invention using terms such as “comprising”,“having”,“including” or“containing” with reference to an element or elements is intended to provide support for a similar aspect or embodiment of the invention that“consists of’, “consists essentially of’, or“substantially comprises” that particular element or elements, unless otherwise stated or clearly contradicted by context (e.g., a composition described herein as comprising a particular element should be understood as also describing a composition consisting of that element, unless otherwise stated or clearly contradicted by context).

The features disclosed in the foregoing description may, both separately and in any combination thereof, be material for realizing the invention in diverse forms thereof

EXPERIMENTALS

A newly developed UV-C decontamination device for washbasin water traps (see Figures 1-9) was mounted on four separate washbasins (HygLab, 211, 103 A and 200B). Experimental design:

In two washbasins UV-C light was active while two washbasins were used as controls without UV- C exposure (part 1). After eight weeks, the experiment was swapped, and the initial UV-C active washbasins were used as controls and the initial control washbasins were exposed to UV-C light (part 2), see Table 1.

Table 1

UV-C Active HygLab, 211 103A, 200B

_

Hyglab means a washbasin in the hygiene laboratory, and 211, 103 A and 200B are specific washbasins in different toilets in the hospital facility.

Collection and identification of samples:

Swabs were taken weekly from the top and the bottom of the washbasin tailpipes and grown on blood agar- and lactose agar plates. Bacteria were quantified semi-quantitatively.

Water was collected from the water traps weekly and serial lO-fold dilutions were made in order to determine total bacterial counts (CFU/mL).

Bacterial colonies were identified by MALDI-TOF MS technique Bacterial counts (CFU/mL):

A marked reduction in bacterial counts was observed within the first week in the UV-C active water traps compared with the control washbasins in both part 1 and 2 of the experiment. Bacterial counts were reduced by a factor 105 - 106 in the UV-C active water traps in part 2 of the experiment (See table 2).

Overall a marked difference in bacterial counts was observed between water traps exposed to UV-C light and control water traps throughout the experimental period.

Within the first two weeks of part 2 of the experiment the bacterial counts in the new control water traps markedly increased to a level similar to the control water traps in part 1 of the experiment (see table 2).

Table 2

Species identified:

UV-C decontamination reduced the total number of different bacteria identified in water traps exposed to UV-C light (UV-C active=5; controls=9).

After exposure to UV-C light was interrupted the total number of species identified increased. Under UV-C light exposure Pseudomonas aeruginosa and Gram negative intestinal commensals disappeared while Stenotrophomonas maltophilia was markedly