The current demand for some types of PPE as a result of the ongoing Covid-19 crisis is unprecedented. This demand is global and the fact is pressure on maintaining supply to all the places it is needed or wanted is inevitable. Current demand far outstrips supply and increasing capacity in response cannot happen overnight. There is unfortunately no avoiding a time lag between the increased demand and the manufacturing capacity response, during which time there are likely to be shortages. And PPE other than that used as part of the Covid-19 response will be affected because the base materials and components used are also used in other types of PPE. As a result, we are receiving many questions regarding the possibility of re-using disposable garments.
Under normal circumstances the simple answer to the question posed in the title of this blog is “never”. These garments are designed to be single use; they should be used once then disposed of appropriately. However, what if the situation is this: the choice is either re-use a coverall or not use protection at all simply because circumstances beyond anyone’s control mean that there are no replacement coveralls to use. Ideally in this case the job should simply be postponed. But obviously in some cases this is not feasible – in the care of suffering patients for example.
So is it reasonable then to re-use garments? Under what circumstances? And if garments are re-used what measures can be taken to minimise risk? This blog considers some of the answers to these questions.
A Word of Caution
Disposable or “single use” garments – whether coveralls, gowns or aprons – are so named for a reason; they are designed to be used once, removed and then disposed of.
There are a number of reasons for this, not least that single use is always safer than re-use; using a new garment every time ensures it will protect as it should. Re-use however is will always increase risk and under normal circumstances we would never suggest it and advise that if the correct PPE is not available the work should be postponed until it is.
However, current circumstances are far from normal; the suggestions in this blog are premised on the assumptions that firstly, the job MUST be done – not doing it is not an option - and secondly, that the user is in a position where the choices are either re-use PPE or not use PPE at all. In this case clearly, whilst re-using is higher risk than using new, it is also lower risk than not using anything (though not always - it depends on circumstances). In which case the question then becomes "what action can be taken to minimise the additional risk of re-using your protective clothing?"
However, this blog is not intended to advocate the re-use of disposable safety clothing but only to provide advice in situations where users have no other alternative.
It is worth pointing out that in PPE the principle of this challenge - that is, of minimising risk is not new. The wearing of any PPE is not about removing risk. It’s a dangerous world and in most cases it is not realistically possible to completely remove all risk. The purpose of PPE rather is to reduce or minimise risk. In general terms the decision to re-use protective garments will inevitably result in the opposite and increase the risk, so under normal circumstances we would strongly advise against it. However, in the current circumstances the reality is that the job must be done and sometimes no suits are available to replace the used one. So clearly re-using it, whilst undertaking a risk assessment to analyse that new risk level and the hazards associated with it, and taking action to mitigate it constitutes the best, or even the only way forward. And the first stage of such a risk assessment is to understand the hazard, the risk and the problem.
Understanding the problem
As a major global manufacturer of protective clothing used mostly to protect against hazardous chemicals we are commonly asked “Can we re-use this garment?" Usually the question is motivated by a desire to use fewer garments and reduce cost.
However, given the reasons this question is currently being asked more frequently than usual is not related to cost and connected especially to clothing for protection against the Covid-19 virus, it is worthwhile clarifying an important distinction; that between protection against hazardous chemicals and against infectious agents such as viruses and bacteria.
The nature of chemicals means they may enter inside a protective garment as a result of either of two different processes:
PENETRATION: through any holes or gaps in the fabric structure or the garment or ensemble (seam holes, zip teeth or tape, joins between garment and other PPE and so on) or,
PERMEATION: through the fabric itself – even if that fabric is a “solid” barrier; whereas penetration will only occur if there are holes or gaps for a chemical to pass through, permeation is a molecular level process that will always occur. It’s just a question of when and how quickly.
The difference between permeation and penetration is explained in the video below.
As a result, a key problem with re-using clothing to protect against chemicals is that the chemical may permeate into the fabric during first use so that the breakthrough time if further contamination occurs during re-use may be much lower than initially so a wearer is less protected than they think.
Bacteria and viruses however are highly unlikely to permeate through a barrier fabric. Such infectious agents will only enter the garment via the process of penetration – by passing through holes or gaps in the fabric structure or garment. (Penetration of different forms of contaminated agent through a fabric structure is addressed by the four tests within the EN 14126 standard – dealt with in previous blogs such as here or here). So unlike in the situation with chemicals, contamination by pathogens such as the virus responsible for Covid-19 will remain on the surface of the garment fabric.
Infective agents – and this appears to be the case with the current virus SARS-CoV-2 (this is the name of the virus – Covid-19 is the term for the disease it causes) – can and will adhere to surfaces and remain active for some time. So the challenge with re-using garments to protect against them is that the outer surface may have become contaminated during the first or previous use. The questions then become "can that contamination be removed or de-activated (i.e. killed)?", and "what measures can be taken during the process of doffing a used garment, processing it and donning it later in order to minimise the risk of spreading the contamination either to the wearer, colleagues or to other surfaces where it might do so?"
How long can SARS-CoV-2 survive on surfaces?
Like so many issues relating to this virus an absolute answer (at the time of writing) is not yet known. However, previous tests on other, similar Coronaviruses indicate the survival period may vary from a couple of hours to several days, depending on factors such as the type of surface and ambient temperature. One study identified a maximum survival time of 9 days but that is probably extreme and unlikely in most circumstances. The best available information suggests survival may be between a few hours and 3 days. In terms of this discussion, survival is therefore quite likely between first and second use of protective clothing.
When is it acceptable to re-use single use coveralls, gowns and chemical suits?
The two important questions are:-
• Is the garment damaged?
Clearly if a garment is damaged it will not protect as designed and should not be re-used. Only undamaged garments with functioning components such as any zip fastening should be re-used.
Can a damaged garment be repaired?
Under normal circumstances we would say no, but, on the basis that pathogens can only enter the suit through penetration and not permeation and that contamination remains on the surface, in extremis small tears or abrasions might be sealed with a good quality, hi-adhesive gaffa or barrier tape, ensuring it is carefully applied with no creases. We would stress that this will not entirely remove the risk associated with damaged protective clothing and normally we would say this is absolutely not an option – partly because there is no practical way of knowing if the integrity of the garment is unaffected, and it may be difficult if not impossible where damage occurs on seams or on areas more difficult to access. But to stress the point again, this blog is based on the premise that there is no alternative to re-use because no new clothing is available, in which case taping up small tears and re-using the garment is probably lower risk than not using any protection at all.
Unfortunately, major damage and tears cannot realistically be repaired.
• Is the garment contaminated?
Again, if the garment is undamaged and uncontaminated then there is no reason why it should not be re-used in any case. If it is contaminated then the possibility of re-use must be ideally avoided and if not avoided, very carefully considered.
The problem in the case of protection against infective agents is that it is likely to be impossible to know whether the garment is contaminated or not. Thus part of an assessment of the possibility of re-use might be to address the question "how likely is it that the garment is contaminated?"
For example, if the garment has been used by front line medical staff in the care of known infected patients then it is highly likely that contamination has occurred – in fact it is reasonable to assume so, in which case re-use of garments should be an absolute last resort and additional measures to mitigate the risk of cross contamination must be all the more stringent.
On the other hand if the garment has been used as part of a cleaning process of surfaces in a room or environment where suspected cases have or may have been present – such as the image here of the worker disinfecting the interior of a bus – then the likelihood of contamination is much lower, the risk less and the suitability of re-use, with precautions, more acceptable.
Once again, this type of analysis cannot remove risk – but can help towards a greater understanding of it, reducing it and thus minimising the probability of cross contamination.
Can contamination be removed from a garment before re-use?
We have received several questions regarding the possibility of decontaminating or sterilising contaminated garments in preparation for re-use.
Whilst we cannot advise on specific types of sterilisation and whether they will kill the virus – although evidence suggests most standard sterilisation/disinfection processes should kill it – (but of course, check with the supplier – we are not experts in this area), the challenge is not killing or removing the virus, it is doing so without damaging the garment and being certain that all traces of the virus have been removed. In particular the latter, knowing whether the process has removed all traces of contamination before re-using, is the key problem. Since there is no easy solution to this it is sensible to assume that all of it has NOT been removed and some residual contamination may remain.
Cleaning & Washing
Note that "cleaning" is a distinct process from "disinfection". Cleaning involves the removal of dirt or other non-hazardous soiling. Disinfection involves a process to actively kill any pathogen contaminating the outer garment surface. Cleaning can be done by simple brushing of any dry soiling and washing with warm water and a mild detergent.
However, disposable garments are not designed to be subjected to any type of automatic washing (or drying) and any such process is likely to damage the garment.
However, these garments are commonly “decontaminated” after use and before doffing and disposal by use of a decontamination shower. If thorough this can be effective at removing contamination and may be a useful process in any case to reduce the possibility of the wearer contaminating themselves before or during doffing (see below).
Disinfecting or sterilising
Most standard sterilisation procedures known to kill viruses and bacteria on surfaces should kill SARS-CoV-2 and can be used on most disposable clothing type fabrics without damaging them with the exception of autoclave (most disposable protective clothing is made from polypropylene and/or polyethylene or other similar polymers so will be damaged by extreme heat – the fabric will soften and melt between 110 – 130oC. To be effective an autoclave must operate at a minimum of 121oC).
We have also received questions regarding the efficacy of spraying garments with alcohol, chlorine or disinfectants in order to kill any active contamination. This process may be effective provided the medium used is effective at killing the virus. Alcohol for example will only work in concentrations greater than 70%. If using such a method the critical points to consider are:-
- That the process of spraying effectively covers the whole garment. An established procedure can help to ensure this and mitigate against the possibility of missing some areas.
- That the disinfectant used is not in itself overly harmful and creates an even greater risk for the wearer – so chlorine, as has been suggested, may not be a good choice.
- That the operator conducting the spraying is properly protected - both from any existing contamination and from the disinfectant used. (This of course may be a problem – the reason this is being done is because of a shortage of PPE – so the person doing the spraying could be using up vital supplies and defeating the object of the exercise!)
- That the disinfectant does not in any way corrode or damage the integrity of the garment fabric or construction.
This last point – that the disinfecting chemical does not damage the garment is obviously critical as clearly if the garment is damaged it will then not protect during re-use – there is little point in a cleaning process to enable re-use if that process destroys the garment.
The use of bleach-based disinfectants
Some users have asked about using bleach as a disinfectant. Most bleaches are based either on chlorine or peroxide – neither of which – especially in the dilute form used for disinfecting purposes - should have an adverse effect on the polymers used in these types of garments (generally polypropylene and/or polyethylene).
However, whatever disinfectant is chosen we would advise checking its acceptability with the garment manufacturer before use. For this the specific chemical in the bleach rather than the brand is required. Safety data sheets should be available from the bleach manufacturer giving specific details. If no information about the chemical, bleach or disinfectant regarding its effect on the garment fabric is available then we would advise conducting a simple test on the garment fabric before use to confirm there are no obvious, adverse effects.
Useful information on general disinfecting principles and methods can be found on the cdc website here and here, and a list of products approved for use against the SARS CoV-2 virus can be found on the US Environmental protection Agency here, and from the European Community ECHA site here.
A further consideration – given that such disinfectants could be harmful – may be to ensure that all traces are removed by rinsing and drying before a garment is re-used.
The challenge is being certain that all traces of the virus have been removed. The reality is there is no easy way of knowing this. For this reason risk can be reduced by ensuring a procedure is established with an ordered, step-by-step method for the cleaning and disinfecting to ensure all parts of the clothing are treated. Pay particular attention to areas of the suit that are more likely to suffer contamination (sleeves / cuffs / front of torso etc). Procedures for donning re-used suits should also assume that residual contamination may remain and be adjust accordingly (see below).
Inspection following cleaning / disinfection
Once a cleaning or disinfection procedure has been undertaken, the garment should be rinsed and dried – ideally by hanging which is less likely to cause damage. Before approving for re-use a thorough inspection should be conducted to ensure the garment remains un-damaged and functional. This should involve:
- Assume some residual contamination may remain on the garment so handle it appropriately (i.e. wear protective gloves)
- Lay the garment on a smooth, flat surface.
- Inspect all areas of the suit, front and back, for abrasion, damages or tears
- Ensure zips and any other components are fully functional
- Examine the seams to ensure they remain intact
- Where sleeves, cuffs or hood feature elastic ensure it remains flexible and fully attached to enable effective joining with other PPE such as masks
- In general ensure the garment remains undamaged. Damaged garments will not protect and should not be used.
Consider the Garment Design
Garments not designed to be re-used may feature elements that do not easily facilitate it so additional measures may need to be taken.
For example, commonly garments designed for single use will feature a strip of double sided tape on the zip cover to enable sealing of the zip. In re-use the adhesion may not be effective in which case additional taping, using a good quality barrier tape to seal down the zip flap may be appropriate.
The importance of donning and doffing
Donning and doffing of protective clothing is always a critical process. An incorrectly donned garment (such as the one above of the image of the worker cleaning the bus interior, where the zip is left partially open) will not protect properly. Meanwhile doffing is perhaps the most dangerous time of all – especially in the case of infectious agent protection. Unseen contamination on the outside of a garment can easily be touched by the wearer or helper.
They key is to establish a written donning and doffing process based on a risk analysis and to ensure that users are properly trained in this process. There are a number of general “do’s and don’ts” to consider and these will probably need to be reviewed and enhanced if garment re-use is being considered. Below is a list - though definitely not definitive - of donning do's and don'ts and doffing do's and don'ts:
1. It can be worthwhile contacting the manufacturer to ask about any specific issues with garments or the donning and doffing processes that you should be aware of. Consider involving them in writing a donning & doffing process; they are (or should be) the expert on the suits they manufacture and can provide useful insight.
2. Always thoroughly read user instructions provided with garments. Information on limitations of use which might be important ought to be included and in particular some garments only achieve advertised levels of protection under specific circumstances – such as adding additional tape to the zip flap.
3. Always use a “buddy system”. That is, work in pairs; parts of a suit-donning process are best done by a helper – and only that helper can effectively conduct a thorough visual check of the suit once donned to ensure there is no damage and that all fastenings are correctly closed.
4. Ideally work repeatedly in the same pairs. That way users get to know the issues and challenges that their regular “partner” suffers and where they might sometimes make errors.
5. Always sit down and remove shoes or boots to don a disposable coverall. Not doing so is more likely to damage it.
6. The final stage before entering a critical area should always be a thorough visual check by the buddy
1. During doffing the same practices must be followed regardless of single or re-use, though re-use might need some additional measures. The key point is to minimise the possibility of cross contamination on the outside surface of the suit and of damaging the suit in the process.
2. Consider the use of a decontamination shower before doffing. This may help to remove any contamination.
3. NEVER remove protective gloves BEFORE removing protective clothing. Doing so means you are highly likely to touch contamination on the suit. Gloves should always be removed after the suit.
4. The suit should be removed by the partner – who should be wearing suitable PPE – gloves as an absolute minimum.
5. A normal process for single use would be to “peel” the garment from the top, turning it inside out (so that contamination on the outside ends up “inside”).
The above might constitute key parts of a normal donning and doffing procedure for single use. However, if garments are to be re-used revisions and additional measures may need to be considered. For example:-
- Whereas in the case of single use the wearer might add gloves AFTER donning the coverall (depending on the connection type), putting on gloves BEFORE donning (to avoid touching any residual contamination on the garment from previous use might be better
- In a normal single use process it would not be necessary for the “buddy” or partner to wear protective clothing during donning. However given the possibility of contamination remaining from previous use at least wearing gloves would be wise.
- Doffing will normally result in a garment ending up inside out as described above. However, this might make processing for re-use more difficult, so removal without turning the suit inside-out might be preferable
- If a garment is to be single use it can be removed without consideration of damaging it. However, if re-use is known to be required then the process may need to be adjusted to reduce the likelihood of damage occurring.
- Single use garments often feature double-sided tape on the zip cover to enable sealing. Designed to be used once, this might be weak on re-use, so additional taping to the zip flap after donning might be appropriate.
The above is not an exhaustive list. The important point is that donning and doffing is a key part of correctly wearing protective clothing and establishing a written process is important. However, if normally single-use garments are to be re-used, given the possibility of residual contamination from previous use, that process might need to be adjusted or revised with additional measures in order to minimise risk.
Unfortunately, if there is one simple answer to the question “can single-use protective clothing be re-used” that answer is “no”. Our policy at Lakeland is that single-use or disposable garments should not be re-used. It is clear that re-use of any clothing (single or multi-use) that protects against hazards – whether chemical or pathogen – increases risk. Risk of contamination during the processes involved in re-use and the risk that on re-use a garment may have been compromised and will not protect as it should.
However, as the saying goes “needs must when the devil drives”. The fact is, in the current global health crisis demand has outstripped the supply chain’s ability to meet it. And supply will take time to catch up. In these circumstances - if replacement protective garments are simply not available and the task must proceed then re-use may be an unfortunate necessity and a lesser risk than not using any PPE at all. In this case action can be taken and procedures instigated that can at least mitigate that increased risk – though users should be clear that it cannot remove it entirely.
Such a decision must not be made lightly. Any drastic change in normal procedure like this - especially since it will increase risk - must be preceded by a suitable risk assessment conducted by qualified personnel in order to identify the risks involved and ensure that procedures are changed and managed in a way to ensure the increased risk is kept to a minimum.
A flow chart summarising an outline system for re-use processing of of single use garments is shown below.
To read more about the importance of conducting risk assessments, download our e-book "Risk Assessments in Multi-Hazard Environments" here