Contact rig

Abstract

A contact rig 1 comprises a body 2 providing a target surface 4, a column 8 extending in a first axis, a first arm 9 and a head element 20; the head element 20 supports a contact element (24, figure 3

Description

Technical Field of the Invention The invention is concerned with a contact rig for undertaking experimental research in the field of contact hazards and evaluation of potential mitigation strategies, in particular under laboratory experimental conditions requiring high levels of biosafety and operation within the constraints of biosafety engineering controls or additional mitigations for toxic chemical handling. In related aspects, the invention is concerned with an associated system, use and methods. Background to the Invention An aspect of hazard assessment research is the determination of the contact hazard to humans posed by an agent present on a surface. The associated risk will often be influenced by many relevant parameters including: the type of agent (e.g. hazardous, or potentially hazardous, biological, chemical, radiological or explosive material); the amount of agent present; the length of time that the agent has been present on the surface; the type of surface (e.g. porous, non-porous); environmental conditions (e.g. temperature, exposure to UV light); the amount of contact by an individual; and the protection afforded by personal protective equipment. Understanding the contact hazard associated with an agent can inform on further experimental research that seeks to identify ways of mitigating against the risk posed by the agent. An important example of hazard assessment relates to research undertaken as part of the global effort during the COVID-19 pandemic. For example, studies have sought to determine the contact hazard to humans posed by the associated agent, SARS-CoV-2, deposited on a surface. Understanding such risks has enabled subsequent studies investigating the efficacy of potential disinfectant practises against SARS-CoV-2 or surrogate virus strains. Such studies have highlighted that the use of disinfectant wipes is highly beneficial as part of a cleaning and disinfection regimen against SARS-CoV-2 on non-porous surfaces. However, Commercial-Off-The-Shelf (COTS) wipes are typically not directly assessed. Instead, the active components of COTS wipes are either assessed in a liquid suspension test, or the components are impregnated onto a single standardised cloth. This is a key factor for considering how such results are to be interpreted, as the instructions for use of COTS disinfectant wipes vary between different manufacturers and, crucially, their use will vary between different operators. Real-world use of disinfectant wipes against viruses is a complex activity to assess experimentally. Such research would benefit enormously from a recognised National or International Standard on which to base studies and, currently, no such Standard exists. A number of European Standards have been employed by different wipe manufacturers attempting to make assessments of disinfectant wipes. These tests typically only provide an indication of efficacy, as either the test is not currently applicable to viruses (‘BSEN 16615:2015. Quantitative test method for the evaluation of bactericidal and yeasticidal activity on non-porous surfaces with mechanical action employing wipes in the medical area (4-field test)’), the test is a liquid suspension test (‘BSEN 14476:2013+A2:2019. Quantitative suspension test for the evaluation of virucidal activity of disinfectants intended for use in the medical area’) or is an application only test (‘BSEN 16777:2018. Quantitative non-porous surface test without mechanical action for the evaluation of virucidal activity of chemical disinfectants used in the medical area’). American Standard ASTM E2967-15 (‘American Society for Testing and Materials: ASTM E2967-15. Standard test method for assessing the ability of prewetted towelettes to remove or transfer bacterial contamination on hard, non-porous surfaces using the Wiperator. ASTM International’) makes use of a bespoke mechanical device, known as the Wiperator, to determine the efficacy of disinfectant wipes. However, this ASTM test is arguably not well suited to experimental research in high level biosafety cabinets due to its electrical operating means, which may impair downstream decontamination practices, and the compact nature of the device, which may present handling and manipulation complications for an operator wearing gauntlets. It is therefore an object of the invention to provide an experimental test system suitable for use in high containment conditions to enable the assessment of the potential contact hazard and transfer potential posed by an agent on a surface, along with the empirical evaluation of mitigation approaches that include evaluating the disinfecting properties of COTS disinfectant wipes in a ‘real-world’ use scenario. Summary of the Invention According to a first aspect, the invention provides a contact rig for a biosafety cabinet, the contact rig comprising: a. a body providing, or capable of accommodating, a target surface; b. a column extending in a first axis substantially perpendicular to the body, the column supporting a first arm extending at a first region away from the column in a second axis; c. a head element, attached to a second region of the first arm, the head element configured in use to support a contact element; wherein the column and / or first arm is rotatable at least partially around the first axis, and in use the contact element is movable relative to the body, such that the contact element can be arranged in: i. a first orientation, wherein the contact element is not aligned with the target surface; and ii. a second orientation, wherein the contact element abuts the target surface, wherein a support element extends substantially perpendicular to the body to stabilise the first arm. It is to be understood that the term ‘target surface’ includes but is not limited to an area of the body that can be associated with the contact element in the second orientation, or a separate element e.g. a coupon, disk or microscope slide that can be placed / secured on the body and provides a surface that can be associated with the contact element in the second orientation. Moreover, it is to be understood that when performing contact experiments, an agent may be placed on the target surface and / or on the contact element, depending on the nature of the experiment e.g.: assessing transfer from the target surface to the contact element; assessing transfer from the contact element to the target surface; assessing performance of a contact element, soaked in a disinfectant, in disinfecting an agent present on the target surface. It is to be understood that the column can be located on or adjacent to the body, in a manner that enables the contact element to be arranged in either the first or second orientation. It is to be understood that the phrase ‘contact element is capable of moving relative to the body’ can incorporate a number of envisaged situations as understood by the skilled person including a) the first arm being able to move in a pivoting manner such that the second region (and thus the contact element) can be arranged at a different vertical height relative to the body; b) the head element being able to independently move such that the head element (and the associated contact element) can be arranged at a different vertical height relative to the body; and / or c) the contact element being able to independently move such that the contact element can be arranged at a different vertical height relative to the body. The contact rig of the invention provides a number of key advantages that in particular relate to undertaking hazard assessment research. The contact rig is an easy-to-manipulate device which negates the requirement for complex operation and / or detailed training for an operator. The mechanical manner via which the contact rig is operated lends well to standardised laboratory approaches which is a clear benefit, for example when comparing the contact risks associated with certain agents of interest or risk mitigation approaches. For example, the contact rig can standardise the contact pressure applied by a contact element to a target surface, as well as the mechanical movement during the application of contact pressure. The contact rig is highly adaptable in terms of the types of contact experiments, via the provision of a ‘contact event’ or series of ‘contact events’ when the contact element is arranged in the second orientation, that can be undertaken e.g.: placing an agent onto a target surface of choice and applying a contact element (e.g. a COTS disinfectant wipe) onto the target surface to assess the level of agent inactivation; applying an agent onto a contact element to understand the level of agent transmission from the contact element onto a target surface. A wide range of agents are envisaged to be suitable for testing with the contact rig e.g. any biological, chemical, radiological or explosive material that can be deposited and assayed. Given the relatively lightweight, compact and yet ergonomically friendly nature of the contact rig, this apparatus is highly suited to experimental work in high level biosafety cabinets, in particular wherein an operator would be wearing heavy gauntlets which may impact on their dexterity. For example, the design of the contact rig offers easy access to the target area while ensuring the moveable elements are easily manipulated by an operator. Moreover, given that the contact rig can be made from purely mechanical parts, this ensures that the contact rig is amenable to decontamination activities such as fumigation i.e. when operated in a high level biosafety cabinet in the hazard assessment testing of a highly toxic / infectious agent(s). Thus, the contact rig can be applied to laboratory containment work ranging from no-to-low containment level bench work against surrogate materials, to high level containment research involving highly hazardous agents under stringent handling conditions and reduced space requirements. Indeed, application of the contact rig of the invention has enabled the assessment of a panel of COTS disinfectant wipes against SARS-CoV-2, thus offering clear real-world benefits in terms of evaluating mitigation approaches to the current global pandemic. Preferably, the second region of the first arm extrudes outwardly through the head element. This feature provides the advantage of a cantilever that can be easily accessed by an operator, in particular to enable the manipulation of the contact element between the first orientation and the second orientation. The first arm acting as a cantilever may enable the reproducible application of a known force, for example a force of 1-15 Newtons being applied by the contact element onto the target surface. Alternative arrangements for manoeuvring the contact element are however envisaged. For example, the contact rig may comprise a motorised element (i.e. an electric motor) that enables the movement of the contact element between the first and second orientation, in particular when applying a reproducible force by the contact element onto the target surface. The motorised element may enable a) the first arm being able to move in a pivoting manner such that the second region (and thus the contact element) can be arranged at a different vertical height relative to the body; b) the head element being able to independently move such that the head element (and the associated contact element) can be arranged at a different vertical height relative to the body; and / or c) the contact element being able to independently move such that the contact element can be arranged at a different vertical height relative to the body. Preferably, the column is supports a second arm extending at a first region away from the column in a plane substantially parallel to the first arm, the second arm connecting at a second region to the head element. This feature provides the advantage of strengthening the connection between the column and the head element. Moreover, this feature enables the first arm, second arm, column and head element to be configured as a parallelogram. As a result, the contact element is able to contact a target surface, when arranged in the second orientation, without any variation in contact angle regardless of the dimensions of elements of the contact rig e.g. the height of the target surface, column etc. The contact rig further comprises a support element extending substantially perpendicular to the body to stabilise the first arm. This feature provides the 28 03 24 advantage of holding or maintaining the first arm in a secure (i.e. non-moving) position which is particularly desired when the contact events involve a toxic / infectious agent and the operator wishes to avoid unexpected movement of the first arm. The support element may enable the contact element being steadily arranged in the first orientation, for example as an intermediary position between individual contact events, and / or in the second orientation when careful manipulation is required to arrange the contact element in the second orientation, for example to standardise the amount of pressure applied by the contact element. Preferably, the support element is a plate located between the column and the target area, the plate having an upper region with a plurality of grooves that enable the first arm to be stabilised in: i. a first orientation, wherein the contact element is not aligned with the target surface; and ii. a second orientation, wherein the contact element abuts the target surface. This feature provides the advantage of a support element offering a plurality of secure positions for the first arm. The grooves may be of the same depth or different depths. For example, the support element provides a first groove in its upper region, enabling the securing of the first arm such that in use the contact element is aligned with the target surface. The first groove may be substantially central relative to the upper region of the support element. The support element also provides in its upper region an at least second groove, adjacent to the first groove, enabling the contact element to be position in an offset manner relative to the target surface. The first groove may be deeper, relative to the at least second groove, to allow the contact element to be arranged in the second orientation, or positioned closer to the target surface when held securely e.g. prior to any further manipulation that might be required to arrange the contact element in the second orientation. Preferably, the first groove allows the first arm to drop far enough that contact can be made without restraint. It is envisaged that one, or a plurality of, weight(s) may be applied to the contact rig (i.e. to the first arm, second arm and / or head element) to adjust the pressure of the contact element when lowered onto the target surface e.g. by manually lifting the first arm from the first orientation and a) moving it sidewise until the first arm is aligned with the first groove in the support plate, and b) lowering the support element until it is sitting on the target surface. Adjustment of the size and position of the weight(s) on the associated part(s) of the contact rig allows for control of the applied pressure of the contact element and thus the pressure applied to the target surface. Preferably, the head element comprises a puck for mounting a contact element. This feature provides the advantage of a convenient surface which a contact element, for example a material item such as a COTS disinfectant wipe, can be arranged against to provide a smooth contact surface. The puck enables the contact rig to be easily and rapidly adapted to test different contact elements in a highly reproducible manner. In particular, a material item such as a COTS disinfectant wipe can be conveniently and tightly secured to the puck via an elastic element such as an O-ring. Alternatively, the head element comprises an artificial digit. This feature provides a human-like appendage for undertaking a contact experiment wherein an operator wishes to assess the contact risk of an agent to an individual e.g. wherein the agent is located on the target surface and / or the artificial digit to understand the potential for agent transmission as a result of contact between the target surface and the artificial digit. It is to be understood that the artificial digit can act as a contact element. The artificial digit may be a representation of a thumb or finger, or example a forefinger or middle finger. In addition, another material may be applied to the artificial digit, for example material used to form a nitrile laboratory glove, such that the effectiveness of contact mitigation, or the risk of agent transmission, via such material can be assessed. Preferably, the contact rig comprises means for moving the contact element and / or the target surface while the contact element remains in the second orientation. This feature offers the advantage of assessing a further parameter of contact experiments such as a rubbing or wiping motion, rather than just merely assessing the effect of downward pressure during a contact event. Preferably, the means for moving the contact element and / or the target surface comprises a rotary element. This feature provides the advantage of enabling a specific form of circular wiping motion being performed by the contact element and / or target surface of the contact rig e.g. circular wiping motion being performed by the contact element. Preferably, the rotary element comprises a rotary handle in communication with the contact element and / or the target surface. This features provides a mechanical means for performing the rotatory action of the contact element and / or the target surface, which negates the need for electric power and may be more amenable to high biosafety decontamination practices. Alternatively, the rotary element comprises a motorised element such as an electric motor. This feature provides the advantage of a standardisable element to ensure highly repeatable contact testing being performed by the contact rig. It is envisaged that the motorised element associated with the rotary element is in addition to any motorised element that enables the movement of the contact element between the first and second orientation. However, alternative arrangement are envisaged e.g. a motorised element may enable the contact element to independently move such that the contact element can be arranged at a different vertical height relative to the body and, additionally, the rotation of the rotary element such that the contact element moves (i.e. rotates) while the contact element remains in the second orientation. Preferably, the means for moving the contact element and / or the target surface comprises a slideable connection or element. This feature provides the advantage of enabling a specific form of lateral wiping motion (i.e. a back and forth manner across the target surface) being performed by the contact element of the contact rig. The slideable connection or element may be associated with the first arm, the head element, contact element and / or body of the contact rig. For example, the body of the contact rig comprises an element capable of laterally displacing the target surface, in particular at a known rate and for a known distance. For example, if the target surface is a separate element that can be accommodated on the body, there may be provided an element, such as an arm or bar, which can abut the target surface and enable a force to laterally displace the target surface. This arrangement enables the lateral wiping motion afforded by the contact element when arranged in the second orientation relative to the target surface. The force provided by the means for laterally displacing the target surface may be provided by the operator or a motorised element. Preferably, the contact rig comprises means for ensuring reproducible placement of an agent on the target surface. The feature enables further standardisation of the performance of contact experiments, in this case with respect to placement of an agent on the target surface, for example a desired number of spots in a desired arrangement. Preferably, the means for ensuring reproducible placement of an agent on the target surface is a sighting tool comprising a substantially transparent element connected to the contact rig via a positioning means. The sighting tool therefore provides: i) a substantially transparent element that can be marked by an operator e.g. in a non-permanent manner such as by a dry-wipe marker pen, enabling the operator to align the marking(s) on the substantially transparent element with the target surface such that the operator, looking through the substantially transparent element at the target surface, can place an agent on the target surface based on the marking(s); and ii) a positioning means that connects, or enables the connection of, the substantially transparent element to the contact rig such that the marking(s) provided on the substantially transparent element can be aligned with the target surface. The sighting tool may further comprise a pre-marked coupon, disk or slide that acts as a sighting standard e.g. to enable marking of the substantially transparent element. While the substantially transparent element is envisaged to be connected or connectable to the contact rig via the positioning means, it is to be understood that this does not have to be a directly connected or connectable to the contact rig i.e. as a result of association with an intermediate element that in the least enables alignment of the substantially transparent element with the target surface. The substantially transparent element and / or the positioning means may be further altered or arranged to account for an operator working at a particular height / angle relative to the target surface. Preferably, the positioning means comprises an arm connecting the substantially transparent element to the body, the arm rotatable relative to the body. The feature provides the advantage of enabling an operator to easily manoeuvre the substantially transparent element relative to the target surface, such that the operator can look through the substantially transparent element at the target surface and determine where to place an agent based on the marking(s) on the substantially transparent element. It is to be understood that the arm may be directly or indirectly (e.g. via an intermediate part such as a stand) attached to the substantially transparent element. According to the second aspect, the invention provides a contact system comprising: a. the contact rig according to the first aspect, wherein the head element comprises a puck for mounting a contact element; and b. a material item to mount the puck as the contact element. According to a third aspect, the invention provides for use of a contact rig according to the first aspect or a contact system according to the second aspect. According to a fourth aspect, the invention provides a method of performing a contact experiment comprising the steps of: a. attaching a contact element to a puck; b. attaching the puck to the contact rig of the first aspect or the second aspect; c. applying an agent to the target surface and / or the contact element; and d. arranging the contact element such that it abuts the target surface. Preferably, the method further comprises the step of moving the contact element and / or target surface while the contact element abuts the target surface. Preferably, the agent is applied to the target surface by: marking the sighting tool according to the first aspect; aligning the marking with the target surface; and applying the agent to the target surface in accordance with the marking. According to a fifth aspect, the invention provides a method of performing a contact experiment comprising the steps of: a. attaching an artificial digit as a contact element to the contact rig of the first aspect; b. applying an agent to the target surface and / or the contact element; and c. arranging the artificial digit such that it abuts the target surface. Preferably, the method further comprises the step of moving the contact element and / or target surface while the contact element abuts the target surface. In addition, another material may be applied to the artificial digit, for example material used to form a nitrile laboratory glove, such that the effectiveness of contact mitigation, or the risk of agent transmission via such material, can be assessed (i.e. the material acts as the surface of the contact element). Preferably, the agent is applied to the target surface by: marking the sighting tool according to the first aspect; aligning the marking with the target surface; and applying the agent to the target surface in accordance with the marking. Any feature in one aspect of the invention may be applied to any other aspects of the invention, in any appropriate combination. In particular, contact rig aspects may be applied to the system, use and method aspects and vice versa. The invention extends to a contact rig, contact system, use or methods substantially as herein described, with reference to the accompanying drawings. In all aspects, the invention may comprise, consist essentially of, or consist of any feature or combination of features. Brief Description of the Drawings The invention will now be described, purely by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a schematic representation from a front view of a contact rig according to one preferred embodiment of the invention; Figure 2 shows a schematic representation from a front view of a support element of a contact rig according to the embodiment of Figure 1; Figure 3 shows a schematic representation from a side view of a head element of a contact rig according to the embodiment of Figure 1; Figure 4, shows a schematic representation from an alternative side view of a head element of a contact rig according to the embodiment of Figure 1; Figure 5 shows a schematic representation from a side view of a sighting tool of a contact rig according to the embodiment of Figure 1; Figure 6 shows a schematic representation from a front view of a contact rig according to the embodiment of Figure 1; Figure 7 shows a schematic representation from a plan view of a contact rig according to the embodiment of Figure 1; Figure 8 shows a sequence for loading a disinfectant wipe onto a puck of a contact rig according to the embodiment of Figure 1; Figure 9 shows a schematic representation of the use of a system according to one preferred embodiment of the invention; and Figure 10 shows recovery of viable SARS-CoV-2 from stainless steel coupons, used in the contact rig according to one preferred embodiment of the invention, when treated for 5 minutes with active or inactive disinfectant wipes. The drawings are for illustrative purposes only and are not to scale. Detailed Description The contact rig of the invention has been applied to determine the efficacy of a range of in-use commercial off-the-shelf (COTS) disinfectant wipes against SARS-CoV-2 on a representative non-porous surface under a single set of experimental conditions. Any changes to the experimental parameters, such as contact time, contact pressure, rotations / pattern of movement, virus isolate and suspension fluid, coupon material, environmental conditions, as well as use of multi-ply wipes, may alter disinfectant efficacy. Methods Cells SARS-CoV-2 Victoria-1 was quantified by TCIDso assay and qualitatively assayed by serial passage in flasks using Vero C1008 cells. Disinfectant wipes A limited panel of disinfectant wipes were selected (these have been anonymised for indication purposes only). Preparation of disinfectant wipes for experiments A single wipe was mounted onto a contact rig puck (hereafter referred to as a “puck”; see ‘The Contact Rig’ section) and immediately placed into a clik-lok sealable box lined with 5 layers of the same disinfectant wipe (to ensure the face of the puck holding the wipe did not dry out). All wipes were used experimentally within 10-30 minutes. Inactive wipes were also prepared by repeated washing steps. The inactive washed wipes were then carefully removed and mounted onto a puck, and immediately placed into a clik-lok box layered with tissue wetted with sterile distilled water (to ensure the face of the puck holding the wipe did not dry out). The Contact Rig A bespoke apparatus termed the contact rig has been designed and engineered for contact hazard assessment and use in high containment facilities. The contact rig has been designed to enable assessment to be made relating to the physical contact of either an artificial digit or a material item, particularly with respect to the latter in assessing the performance of COTS disinfectant wipes. The newly developed contact rig can standardise: i) the placement of virus and wipe; ii) the contact pressure applied; and iii) the mechanical movement during the application of contact pressure. The contact rig is predominantly made from 304 and 316 grade stainless steel, Delrin®, Bakelite®, Nylon® and brass. As such the rig is inherently capable of withstanding decontamination process of fumigation, and sterilisation by autoclaving. The contact rig operates without motorised parts, a significant safety consideration when working in high containment, enabling its use in e.g. laboratory containment systems such as a standard size Class 3 microbiological safety cabinet. Figure 1 shows contact rig (1) as a manually operated device, measuring approximately 37 cm (W) x 50 cm (D) x 37 cm (H). Contact rig (1) comprises a body (2) held above the ground by four legs (3a-d; only legs 3a and 3b shown in Figure 1). Body (2) provides a surface for housing (4), in the form of a petri dish base, housing (4) held in place by screws (5a, 5b). Housing (4) contains a stainless steel coupon (6a), acting as a target surface upon which an agent (either in liquid form or the agent contained in a liquid) can be deposited via a pipette. Upstanding from body (2) is a support element (7) (described in more detail in Figure 2 and the accompanying description). Located behind the support element (7), as viewed from the front of the contact rig (1), is a rear column (8) arranged on a base (not shown; see Figure 9a) such that rear column (8) is capable of rotating relative to body (2). Associated with rear column (8) is a first arm (9) and a second arm (10), which extrude from rear column (8) from one respective end region of first arm (9) and second arm (10), such that rear column (8) is effectively a rear arm support column. First arm (9) and second arm (10) can be moved in an arc either left to right or right to left on account of rear column (8) being capable of rotation. Rear column (8) is attached to body (2) by clamping the flat base (not shown) of rear column (8) to the surface of body (2) using a bolt (not shown) fitted into rear column (8) from below the body (2). The bolt was originally fitted with a heavy spring between the head of the bolt and the underside of the body (2) to prevent wobble and enable smooth rotation of the first arm (9) and second arm (10) from side to side. This spring arrangement has been replaced with a pair of bearings (not shown) fitted above and below the body (2) which allow arms (9, 10) to rotate freely at 360° but not to move otherwise. This movement allows arms (9, 10) to be lifted (as described below) and rotated to either be placed at rest in a convenient position or moved and lowered down to facilitate a contact test on a stainless steel coupon (6a). Rear column (8) is fitted with a pair of removable blocks (11a, 11b) (shown in Figure 9A) to allow some course height adjustment of first arm (9) and second arm (10). This allows the arrangement of contact rig (1) to be optimised when arms (9, 10) are horizontal and contact is made between a contact element and stainless steel coupon (6a). The weight of the first arm (9) in particular ensures the same contact pressure is applied to the stainless steel test coupon (6a) each time of use of the contact rig (1). A fixed contact pressure of 2.6 kPa was selected as it is within the range of the British Standard used to assess efficacy of disinfectant wipes against bacteria and yeast (BSEN 16615:2015, commonly referred to as the “4-field test). At the opposing end region of first arm (9) and second arm (10) is a head element (20) (described in more detail in Figure 3 and the accompanying description). A sighting tool (30) (described in more detail in Figure 4 and the accompanying description) is associated with body (2) and enables the operator to standardise the placement of an agent onto e.g. stainless steel coupon (6a). Figure 2 shows support element (7) upstanding from body (2), support element (7) having minor grooves (8a-d) and a major groove (8e). Minor grooves (8a-b) enable the first arm (9) to be secured in a manner such that the head element (20) (not shown) is not aligned with stainless steel coupon (6a) (not shown). In Figure 2, the first arm (9) is positioned in minor groove (8a), securing the first arm (9) in such a rest position with fine adjustment using the slotted bolts (not shown) holding the rest. Once securely in the selected rest position, the head element (20) (not shown) can then be loaded or unloaded with either a puck (24) (not shown) for disinfectant wipes, or an artificial finger. Securing the first arm (9) in the major groove (8e) enables a contact element (not shown), associated with head element (20) (not shown), to be aligned with the stainless steel coupon (6a) (not shown) in a manner that ensures no significant lateral movement takes place when the head element (20) and puck (24) moves down onto the stainless steel coupon (6a) (not shown). Figure 3 and Figure 4 shows the head element (20) of contact rig (1), comprising a main auxiliary unit formed from two parts, front column (21) and back plate (22) comprising flanges (22a, 22b). Front column (21) is capable of holding an artificial digit (not shown) via a screwed connection (not shown) at the base of front column (21). As shown, back plate (22) is capable of holding a wipes mechanism comprising brass collar (23a), rotary hex chuck (23b) with locking ring (23c). Rotary hex chuck (23b) / locking ring (23c) is a COTS part (item number DeWalt 60mm Bit Holder (screwfix-975GX)). Rotary hex chuck (23b) is steel coated and considered to be disposable and easily replaced in situ. It is anticipated that hex chuck (23b) will be able to withstand a considerable number of decontamination cycles by fumigation and sterilisation by autoclaving. Attached to the bottom of rotary hex chuck (23b) is a detachable puck (24), to be sterilised prior to use and is capable of being clicked on or off the rotary hex chuck (23b). Puck (24) is made from Delrin® and silicone foam rubber and considered to be disposable. Puck (24) is autoclavable for re-use; care must be taken to inspect puck (24) for structural integrity before re-use. Puck (24) provides the surface to which a disinfectant wipe can be attached. Puck (24) is attached to the hex chuck (23b) via a hex pin (24a; see Figure 9A) on puck (24). Brass collar (23a) is show extending through flanges (22a and 22b) of back plate (22). Back plate (22) is held in place onto the side of the front column (21) by four plastic screws (25a-d). A small grub screw (25e), located above flange (22a), secures hex chuck (23b) inside brass collar (23a). The tightness of grub screw (25e) should be checked after carrying out any decontamination process or autoclave cycle. Moving the head element (20) (via e.g. rear column (8)) enables easy placement or removal of the puck (24). At the top of brass collar (23a) is a rotary handle (26), connected via bar (27), which an operator can turn to enable puck (24) to make 360° rotations. This action can be applied when a disinfectant wipe is attached to the puck (24) and subsequently contacting the target surface provided by the stainless steel coupon (6a) (not shown). The rear column (8), first arm (9), second arm (10) and head element (20) are configured as a parallelogram with four corner bearings (not shown) which rotate in the plane of the parallelogram. The bearings are fitted where first arm (9) and second arm (10) pass through slots (28a, 28b) in front column (21) and slots (28c, 28d) (see Figure 7) in rear column (8). First arm (9) is held in place in slot (28a) via bolt (29a). Second arm (10) is held in place in slot (28b) via bolt (29b). Corresponding bolts (not shown) are associated with slots (28c, 28d) in rear column (8). Slots (28a-d)) which house the first arm (9) and second arm (10) are long enough to allow for the vertical swing of arms (9, 10). The bearings allow the head element (20) to be raised or lowered while being restrained from any movement that is non vertical. Therefore the puck (24) or finger will touch down on the stainless steel coupon (6a) without any variation in contact angle, regardless of the height of the coupon (6a) or target surface, or height of the equipment fitted to head element (20). Figure 5 shows the sighting tool (30) of contact rig (1) comprising rotatable arm (31) connected to the body (2) via bolt (32). At the other end of rotatable arm (31) is a stand (33), capable of engaging the surface upon where the contact rig (1) is placed. At the top of stand (33) is arm (34) and adjustable arm knuckle (35) which provides a connection to a transparent element (36), in the form of a petri dish lid. Adjustable arm knuckle (35) allows the correct angular alignment of transparent element (36) to the user. Figure 6 and Figure 7 shows the contact rig (1) with the sighting tool (30) configured such that the transparent element (36) is in alignment with the target surface provided by the stainless steel coupon (6a, 6b), when the contact rig (1) is positioned directly in front of an operator. As shown in Figure 7, the transparent element (36) can be marked in pen ink by an operator, as shown by lines (36a, 36b), against a premade template coupon (6b) to provide a template to enable the accurate placement of e.g. 5 x 1 pL droplets of agent on the stainless steel coupon (6a) (not shown), as well as ensuring the agent is not placed too close to the edge of the stainless steel coupon (6a). This placement is operator specific as it depends if the operator is sitting / standing at a microbiology safety cabinet and the height of the operator. The sighting tool (30) therefore enables the placement of an agent on a target surface in an easy and consistent manner when performing contact assessment experiments. With reference to Figure 6 and 7 in use, transparent element (36) (which can be easily replaced by slotting in a new one) is angled in such a way that when rotatable arm (31) is positioned to be in front of the target surface i.e. stainless steel coupon (6a), an operator can mark the transparent element (36) with the reference shape of the stainless steel coupon (6a) and where the placement of agent needs to be. This is achieved using a template coupon (6b) with markings on it, and must be performed by the operator to ensure sufficient visual accuracy. The sighting tool (30) will be prepared first and then swung back out of the way (as shown in Figure 1) to enable the first arm (9) with attached puck (24), to move into position when ready. Figure 8 (A-K) shows the sequence for loading a disinfectant wipe onto puck (24). Puck (24) is loaded with a silicone foam rubber base (not shown) and then placed upside down in a stand (40). A wipe (50) is placed over the upturned puck and the O-ring mounting tool (41) is placed onto it The O-ring mounting tool (41) has had a stretched silicone foam O-ring (42) already fitted onto it with the tight end toward the puck (24). Once in place, the foam O-ring (42) can be ‘flipped’ down onto the body of the puck (24) clamping the wipe (50) tightly against the base. Adjustment may be need to ensure a tight and crease-free fit is achieved. Once loaded on the puck (24), the wipe (50) can be trimmed or tidied with an elastic band as necessary. Puck (24) is carefully handled when mounting a disinfectant wipe (50) to ensure the mounted wipe (50) is crease-free and is not touched by the operator. With reference to Figures 7 and 9A-D, a schematic representation of use of the contact system is shown. Prior to use, the contact rig (1) should be checked for looseness and correct positioning, the first arm (9) and rotatable sighting tool arm (31) (not shown) adjusted for the user and the transparent element (36) marked as required using a pen. As shown in Figures 9A-B, when the first arm (9) is positioned in minor groove (8a) of the support element (7), the hex chuck (23b) is operated by moving locking ring (23c) down toward the puck (24), acting to open the hex chuck (23b) and enabling the hex pin (24a) on the puck (24) to be pushed into the hex chuck (23b). Releasing the locking ring (23c) acts to lock the hex chuck (23b) into position. As shown in Figures 9C-D, once the contact rig (1) is loaded and ready, an operator manually moves first arm (9) into the major groove (8e) in the support element (7). Using first arm (9) as a lever therefore enables puck (24) to be manually lifted by an operator in a long vertical arc while maintaining parallelism with the body (2) of the contact rig (1). Once the first arm (9) is secured in major groove (8e), the first arm (9) can be lowered until puck (24) comes into contact with the silicone steel coupon (6a). The rotary handle (26) can then be rotated 360°, or as required, to enable contact wiping of the stainless steel coupon (6a) by wipe (50). After the contact experiment is performed, the first arm (9) can then be lifted and returned to the original resting position e.g. in minor groove (8a) so that the puck (24) can be unloaded from the hex chuck (23b) and the disinfectant wipe (50) discarded. Disinfectant wipe assay All experiments were performed on a non-porous surface made of stainless steel (6 cm2 coupons cleaned by way of submersion and agitation in 70% ethanol for 5 minutes followed by four washes in sterile distilled water). In triplicate, 5 x 1 pL volume droplets of virus were inoculated onto the stainless steel surface (held within the sterile petri-dish) using the sighting tool (see ‘The Contact Rig’ section), and the wipe, mounted on the puck, was placed directly in contact with the coupon before rotating the wipe clockwise-anticlockwise a total of 5 x 360° rotations. The wipe remained in contact with the coupon for a total of 5 minutes (inclusive of time to perform rotations) before samples were recovered from the stainless steel coupon into 10 mL tissue culture medium (TCM) and mixed three times by pipetting. Samples were then washed using a centrifugal concentrator (Millipore Amicon® ultra-15 centrifugal unit). Results Disinfectant wipe assay using the Contact Rig The disinfectant wipes (WN1 and WN2) were prepared in a Class 2 microbiological safety cabinet and transferred directly to the high containment laboratory for assessment. Working stocks of SARS-CoV-2 were inoculated onto stainless steel coupons and immediately treated with active or inactive disinfectant wipes (Class 3 MSC conditions). The coupon surface was subjected to a total of 5 minutes contact time with the disinfectant wipe, inclusive of 5 full rotations on the puck face. Where a disinfectant wipe was not used (positive control; virus only), the virus was recovered into 10 mL TCM after 5 minutes, processed as described for test samples and enumerated. The active candidate disinfectant wipes demonstrated a mean reduction in viral titre of >4 Logw TCIDso / mL (Figure 10. Virus only-no wipe (triangles). *** A statistically significant difference was observed (p <0.001). LLOQ; lower limit of quantification (10 TCIDso / ml). ‘Virus’: positive control). No viable virus was detected from samples treated with wipe WN1 (quantitatively by TCIDso assay and qualitatively by serial passage in flasks). Of the three active WN2 replicates, 1 / 3 was positive but not quantifiable in the TCIDso assay (below the LLOQ), and subsequently scored positive for CPE by serial passage in flasks (indicating <10 TCIDso / ml was present in at least 1 / 3 of these samples). The use of an inactive wipe produced varying results, likely to be linked to the type of materials used by the manufacturer in the particular wipe matrix. Conclusions The use of disinfectant wipes is vast and commonplace, and whilst many manufacturers have claims about virucidal activity either against SARS-CoV-2 itself or other enveloped viruses, there is in fact no standard test available for the relevant COTS real-world testing of disinfectant wipes against viruses. Use of the bespoke contact rig has enabled empirical assessments of a limited panel of COTS disinfectant wipes in a manner more fitting of Teal-world” use than the Standard suspension test or alternative liquid disinfection assay. Further, the Standard 4-field test employs surrogate microorganisms to enable the testing to be conducted without the need for high containment facilities which are restrictive environments, requiring specialised and highly skilled operators. The sample data herein provides strong evidence that COTS disinfectant wipes are effective at disinfecting a stainless steel surface inoculated with SARS-CoV-2 (liquid inoculum only) when used for a contact time of at least 5 minutes. WN1 was, at the time of testing, the only product to have been previously empirically assessed against SARS-CoV-2, with a virucudal claim based on BSEN 14476:2013+A2:2019 - a suspension test used to evaluate efficacy of liquid disinfectants. This compares with the data herein whereby the active components from WN1 performed well in a liquid disinfection assay and reduced the viral load to undetectable levels when exposed to an active WN1. It will be understood that the present invention has been described above purely by way of example, and modification of detail can be made within the scope of the invention. For example, with respect to Figure 1, while the contact rig (1) is a manually operated device and contains no driven parts, the standardisation of e.g. the contact or the wiping motion may be augmented by the incorporation of motorisation. For example, a modification may be made to the contact rig (1) wherein arm (9) is placed into the top of major groove (8e) and sits on a horizontal bar attached to a vertically positioned electric linear actuator. Upon application of electrical potential to the linear actuator, the horizontal bar lowers the arm (9) down the major groove (8e) until puck (24) or an artificial digit is resting on the stainless steel coupon (6a). This movement controls the contact velocity. The velocity can be adjusted by modifying the applied voltage to the actuator. The arm (9) can be recovered to the high position by reversing the electrical potential to the linear actuator and then moving the arm (9) manually to a rest position (e.g. in minor groove (8a) to restart the process with another stainless steel coupon (6a). A long levered switch may allow potential reversal while wearing gauntlets etc. Each feature disclosed in the description, and (where appropriate) the claims and drawings may be provided independently or in any appropriate combination. Moreover, the invention has been described with specific reference to a contact 5 rig, in particular a contact rig for performing contact hazard assessment such as the assessment of COTS disinfectant wipes. It will be understood that this is not intended to be limiting and the invention may be used more generally. For example, the invention may be used in other fields requiring the application of contact and / or pressure. Additional applications of the invention will occur to the 10 skilled person. 28 03 24

Claims

1. An apparatus for assessing the contact hazard posed by an agent and / or evaluation of mitigation approaches against said agent, the apparatus 5 comprising:a. a body providing, or capable of accommodating, a target surface for placement of the agent;b. a column extending in a first axis substantially perpendicular to the body, the column supporting a first arm extending at a first region away from the 10 column in a second axis; andc. a head element, attached to a second region of the first arm, the head element comprising a contact element or providing a surface on which a contact element is mounted;wherein the column and / or first arm is rotatable at least partially around LO 15 the first axis, and in use the contact element is movable relative to the body, and wherein a support element extends substantially perpendicular to the body to stabilise the first arm, the support element provided by a plate located between the column and the target area, the plate having an upper 20 region with a plurality of grooves which can individually secure the firstarm, such that the contact element and the first arm can be respectively arranged and stabilised in:i. a first orientation, wherein the contact element is not aligned with 25 the target surface; andii. a second orientation, wherein the contact element abuts the target surface.

2. An apparatus according to Claim 1, wherein the second region of the first 30 arm extrudes outwardly through the head element.

3. An apparatus according to Claim 1 to Claim 2, wherein the column supports a second arm extending at a first region away from the column in a plane substantially parallel to the first arm, the second arm connecting at a second region to the head element.

4. An apparatus according to any preceding claim, wherein the head element comprises a puck for mounting a contact element.

5. An apparatus according to Claim 1 to Claim 4, wherein the head element 10 comprises an artificial digit.

6. An apparatus according to any preceding claim, wherein the apparatus comprises means for moving the contact element and / or the target surface while the contact element remains in the second orientation.LO 15r\iK M 7. An apparatus according to Claim 6, wherein the means for moving thecontact element and / or the target surface comprises a rotary element.

8. An apparatus according to Claim 7, wherein the rotary element comprises 20 a rotary handle in communication with the contact element and / or the target surface.

9. An apparatus according to Claim 7, wherein the rotary element comprises a motorised element.2510. An apparatus according to Claim 6 to Claim 9, wherein the means for moving the contact element and / or the target surface comprises a slideable connection or element.30 11. An apparatus according to any preceding claim, wherein the apparatuscomprises means for ensuring reproducible placement of an agent on the target surface.

12. An apparatus according to Claim 11, wherein the means for ensuring reproducible placement of an agent on the target surface is a sighting tool comprising a substantially transparent element connected to the apparatus via a positioning means.

513. An apparatus according to Claim 12, wherein the positioning means comprises an arm connecting the substantially transparent element to the body, the arm rotatable relative to the body.10 14. A system comprising:a. the apparatus of Claim 1 to Claim 13; andb. a material item to mount part of the head element as a contact element.

15. A method of performing a contact experiment comprising the steps of:15a. attaching a contact element to part of the head element of the apparatus according to Claim 1 to Claim 13 or the system of Claim 14;b. applying an agent to the target surface and / or the contact element; andc. arranging the contact element such that it abuts the target surface.20 16. A method of performing a contact experiment comprising the steps of:a. attaching an artificial digit as a contact element according to the apparatus of Claim 5 to Claim 13;b. applying an agent to the target surface and / or the contact element; andc. arranging the artificial digit such that it abuts the target surface.2517. A method according to Claim 15 to Claim 16 further comprising the step of moving the contact element and / or target surface while the contact element abuts the target surface.30 18. A method according to Claim 15 to Claim 17, wherein the agent is appliedto the target surface by: marking the sighting tool according to Claim 12 to Claim 13; aligning the marking with the target surface; and applying the agent to the target surface in accordance with the marking.

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