Controlling skin irritations and allergens23 February 2021
Richard Neale of LTC Worldwide has antidotes for the perennial problem of controlling skin irritations and allergens, whether laundry products or tiny amounts of food product left in food production textiles that could cause anaphylactic shock and even death
Skin irritations have long been an occasional but annoying problem for launderers, with many puzzled investigations often leading to inconclusive results. The whole question of irritation has become much more serious with the steady increase in allergenic reactions which some users experience, even when exposed to very tiny amounts of a substance to which they are sensitive. Occasionally the reaction is so serious that the anaphylactic shock experienced by the user leads to death before palliative treatment can be given by medical professionals. This means that some customers, especially those in the food industry, now require justified assurance from the garment launderer that the clean garments being regularly supplied offer only a negligibly low risk. This month we address the general problem of skin irritation which can affect every launderer, together with the more specific and serious risk which must be handled by those supplying food industry garments.
What are the main causes of skin irritation?
When a user experiences a genuine case of skin irritation linked to a workwear garment or a hotel towel or pillowcase, resulting in a rash, reddening of the skin or blistering, there are several possible causes which could be linked to inadequate laundering.
How is skin irritation avoided?
Elimination of sodium hypochlorite (chlorine bleach) from laundry processes is reducing the incidence of skin rashes caused by excessive bleaching or inadequate rinsing of the bleach. The residual risk can be minimised by automatic dosing and removal of any manual additions. If all else fails, then an antichlor can be added in the final rinse to neutralise any remaining risk.
Launderers minimise water consumption by tuning the rinse dips down to the permissible minimum (making good savings in water and effluent charges), but this must be done in the correct way. This means checking the alkalinity of the final rinse going to drain to ensure that this does go above the allowable maximum (which is 0.04 gram/litre above the alkalinity of the incoming soft water supply). The best antichlors (see previous paragraph) such as those based on sodium metabisulphite, will also neutralise residual alkali from the detergent and lower the risk of this giving rise to wearer irritation. If the wash process uses an acid addition in the final rinse, such as peracetic acid, the dosage must be carefully controlled so as to keep the acidity in the final bath close to neutral (in the range pH6.5 to pH 7.0 for example). The detergent system suppliers should be well able to assist with this.
Cross-contamination with fine particles from other work (such as fire-damaged textiles) is less common, but if it does occur it is usually down to an error in classification. Textiles with soot on them should never be mixed with one-night hotel sheets for example. Fire-damaged work needs extra alkali and non-ionic components to deal with smoke tars and a much higher level of suspending agent to wrap around the soot particles and carry these safely to drain. Even with these precautions, a hotel pillowcase could still smell smoky, if washed in the wrong load. It only takes a few particles to irritate the olfactory system in the human nose!
Reacting to reports of skin irritation
Skin irritations are not going to go away. If anything, they seem to be occurring more frequently and when they do appear, they rarely affect just one person. They might start with the outbreak of a rash on just one sensitive worker, but it is surprising how many other colleagues then notice red patches appearing on their necks, wrists or ankles! Their shift supervisor will probably have no hesitation in blaming the laundry and demanding instant action! It therefore pays the laundry to be ready to conduct a rapid investigation on-site, on the overalls being worn by the affected wearers.
The best way of detecting residues of sodium hypochlorite is by smell. It is not called ‘chlorine bleach’ for nothing! Rub the fabric in the suspect area of the garment together to warm it up and then sniff it briefly. If you can detect the characteristic chlorine odour, the problem is being caused by poor removal of bleach in the rinse. This method will also pick up soot residues from cross-contamination and the vinegary smell of peracetic acid from incorrect neutralisation in the final rinse.
Alkali residues from detergent overdosing or poor rinsing can be detected by moistening the area with de-ionised water and holding a piece of red litmus paper against it. If it turns from red to blue, then the cause could well be residual alkali.
These checks can be done quickly on-site by a member of the customer service team (with appropriate training).
If both of these checks prove negative, then the cause is either something much less usual (which will need laboratory testing of the garment fabric) or the rash has nothing to do with the laundry.
What is an allergen?
An allergen is a component, usually of a foodstuff, to which a small percentage of human beings are peculiarly sensitive. The sensitivity varies from a mild rash affecting the skin right through interruption of different body functions and in extreme cases, severe anaphylactic shock which, if not treated promptly, can cause death. As a result, most food manufacturers now go to significant lengths to avoid contamination of garments with allergens from those foods that do contain them.
A list of typical known allergens is given in the table. Launderers offering a contract laundering service (or garment rental) to food industry customers now find that in most cases they are required to provide justified guarantees, to these customers, that the risk of an reaction occurring (in a consumer) to any one of these allergens, is reduced to a negligibly low level. This is a big ask, because the ‘negligibly low level’ required is usually at or near the lower limit of detectability of the allergen on the surface of the work wear garment that has been decontaminated. The maximum allowable levels are generally measured in parts per million.
The methods of detection are laboratory based and in order to give justified assurance the laboratory needs to be independently certified as to its competence and the adequacy of its processes (which are generally based on internationally agreed procedures). It is neither practical nor economic to lab check every garment prior to despatch from the laundry. It has been found that an annual check on the decontamination levels being achieved with every potential allergen listed is adequate to validate the wash processes, procedures and equipment used in each laundry. This is backed up by additional monitoring visits by technical staff from food industry users, together with intermediate checks by the laundry on the power of the processes in use, with respect to those wash parameters which have been shown to be critical to allergen removal.
How can allergens be effectively removed?
Most allergens are proteinic in nature, which gives a good guide to methods for effective removal. Proteins are removed using a controlled, low-temperature stage (40C maximum) to first soften the proteins, followed by a main wash, usually at a higher temperature, with plenty of detergency, good mixing and mechanical action. This means using a professionally designed process (with a good emulsifier for fatty, oily proteins) and the correct loading factor. This is turn calls for correctly weighed loads and accurate process selection. If this is done correctly then only a low level of oxidation is needed, because this only has to remove vegetable dye stains. Protein stains will come out with the wash process design described.
How powerful does the wash process need to be?
If the wash process is correctly designed there should be no need for harsh or unduly aggressive chemistry. If the process selected is found to leave residual allergens on the textile, for example, the solution is not to increase the dosage of sodium hypochlorite!
This might well destroy allergens, but it will also degrade any cellulosic fibres (such cotton) in the textiles. The correct approach is to go back through the process design using the guidance given earlier and find out what might be wrong with it. An intelligently designed wash process will give garments which are white and stainfree with no odour at an affordable cost.
The tricky bit is to ensure consistency load to load, so that the customer can be given assurance that not only do you have the right procedures, but these are being used correctly every time, day in day out.
How to give the customer justified assurance with regard to allergen removal
Once the correct processes and procedures have been identified and implemented, you will need a laboratory check on the adequacy with respect to allergen removal.
The ideal time to do this is when you have work going through which you know to be contaminated with food industry soiling and staining, so that you can remove a random sample of a wrapped, processed garment for analysis.
Some might regard allergens as a major problem for the contract launderer or for the rental operator. Others see it as an opportunity, because removal of allergens simply requires disciplined application of professional laundering skills. This is why it is unwise for a food processor to undertake in-house laundering unless they are prepared to acquire the necessary craft skills needed for effective removal of allergenic proteins – skills which are second nature to the competent laundering professional, used to handling modern food industry workwear.
Trade Secrets: Treading Water
High Street businesses around the world are coping with localised restrictions and cleaners face ongoing uncertainty in the months ahead as the future path of the pandemic and Governmental response cannot be predicted. Despite the promise of innoculations rolling out in the spring and summer, national or local lockdowns may again be imposed in an effort to reduce the spread of the virus and if struggling cleaners are to survive they will have to reduce operating costs to the bare minimum.
I have previously discussed some measures cleaners can consider to diversify and support their turnover, now a close look at the costs of production might produce some very worthwhile savings enabling them to tread water and survive.
While some businesses closed during lockdowns, many introduced limited opening hours. The second and third waves of the pandemic may result in an even greater loss of footfall this winter, so a close look at footfall over the week with a view to reducing opening days and hours could result in significant savings. Plan well ahead and inform customers to avoid any unnecessary inconvenience. For some businesses with large orders, home delivery on a closed day may help support turnover from regular customers. Even opening one day a week is likely to go a long way towards retaining your customer base.
Drycleaning machines generally use a similar amount of solvent and energy to clean a part-load as is required to clean a full load, so think about service times. Way back in the 1950s service times were up to a week; extending service times allow you to build up larger loads of, say, silks and whites thus reducing the number of loads you need to clean.
Drycleaning machines are heavy on energy, much more so than wetcleaning machines, and tumble dryers and finishing equipment are also heavily dependent on electricity or gas and therefore every effort needs to be made to reduce costs in these two areas.
Take a long hard look at the distribution of your incoming work over the past four weeks The objective being to reduce the number of days you operate and the number of cleaning cycles to the absolute minimum. I know of cleaners who during lockdown were only operating their cleaning equipment twice in a month and then increasing to once a week when things began to improve.
If the solvent is in good condition, and only a lightly soiled medium or light load has to be cleaned, a good cost reduction is possible if a ‘no pump to still’ programme with filtration is used and the still is not turned on. However, it is always better to wait until several loads can be cleaned using a range of programmes and don’t start up the finishing equipment until you actually need to use it. If possible, ensure all your loads have been cleaned and spotted so that finishing equipment can remain in constant use for the shortest time.
Finally, don’t forget the lights: if they are not needed turn them off.
Roger Cawood FGCL