Soap suds and savings

Washrooms can account for a significant percentage of water use in offices. But, say Ann Durrant and Alexandra McKay, companies can reduce their impact on this natural resource and save money by switching from lotion to foam soaps and changing their employees handwashing technique

Many organisations are striving to reduce their environmental impact and in the process save money by using less energy and natural resources. Water is one such natural resource, which is becoming increasingly scarce as the global population grows.

Independent research studies conducted in the UK in 2009 have shown that water consumption during hand washing can be reduced by between 16% and 45% by simply using foam soaps rather than traditional liquid/lotion soaps. For every 100 people employed, this equates to a potential annual reduction in water usage of as much as 56,000 litres. Importantly, the research shows that handwashing with foam soaps rather than lotion soaps can be achieved with no loss of cleansing efficacy or inconvenience to the user.

Water consumption and the potential savings is an important issue that is set to increase in focus in the future. Water reduction targets are being set by governments and businesses alike. The UK Government, in an attempt to lead by example, has set a target to reduce water use by 25% on its office and non-office estate by 2020 compared with 2004/2005 levels. While China has set itself a target to reduce water consumption per unit GDP by 60% by the year 2020.

Water scarcity is a real and growing issue. Only 2% of the world’s water is fresh water and most of that is frozen in glaciers or deep underground. This leavzes only a very small percentage available for human use and consumption. Increasing population, consumption and changes in climate are all putting pressure on these stocks. By 2025 the UN expects that 1.8B people will be living in water scarce countries or regions. This is not just an issue that affects the developing world. Nine European countries can be considered water-stressed, including Cyprus, Bulgaria, Belgium, Spain, Malta, Macedonia, Italy, UK and Germany, as well as parts of the US and Australia. Basically, water is a finite resource that we need to conserve.

While organisations may be using recycled paper and energy efficient light bulbs, they may overlook how the washroom contributes to their environmental impact. But for many office-based businesses, the washroom can be where a large proportion of their water is used.

Washrooms account for around 65% of water use in the average office which, without a canteen, uses 25 litres per full time employee per day. There are many ways to save water in washrooms; hippos in toilet cisterns, fixing leaking taps, fitting spray nozzles. These small changes can save a lot of water and money. For example, a dripping tap can waste 5,000 litres of water a year and cost around £400.

One other opportunity that needs to be considered is the choice of soap.

Significant savings
Deb Group commissioned independent research to understand whether using foam soap for handwashing affected people’s hand wash behaviour and water use. Wall-mounted, nonaerosol foam hand wash systems were invented by Deb in the mid-1990s. In simple terms, the integrated pump in the cartridge takes a special formula liquid soap and mixes it with air to increase its volume by ten times and provide an instant lather for hand washing.

Researchers asked 150 people to place their hands in compost to simulate a moderate level of dirt and then wash their hands, once with a traditional liquid/lotion soap and once with foam soap. Participants were free to use their handwashing method of choice and to control the tap, and hence water flow rate, as necessary. The product tested first was rotated to avoid order effects and all the participants used liquid/lotion or foam soaps on a day–to-day basis.

When testing the lotion soap, participants used an average of 1,758ml water with the tap on for 21.8 seconds. For foam soap, this reduced to 1,475ml water with the tap on for 19.7 seconds. This amounted to a 16% water saving. If we presume people wash their hands three times a day at work, an office of 100 people currently using lotion soap would save nearly 20,000 litres of water a year by changing to foam soap.

The research also looked at the different methods people used to wash their hands. There were three main methods used during the test, adopted by around 85% of respondents. The remaining 15% used another four alternative methods, which included pre-wetting hands, and filling the sink with water. Most people, completely spontaneously, used the same handwashing method with both products. This shows that the reduction in water use is directly related to the product format rather than the handwashing method used.

In addition to measuring water usage, participants were asked to describe their experience. Foam and lotion soap were both rated highly, with a marginal preference for foam - 86% said that the foam soap was about right based on the amount of lather and the length of time it took to rinse off compared to 84% for lotion soap.

It is believed that less water is required for rinsing because foam soap spreads more easily on the hands than lotion soap. While structurants are needed to thicken lotion soaps, the handfeel of foam is given by bubbles of air which could influence spreadability.

To confirm and quantify this effect, Deb conducted a simple experiment to compare the spreadability of foam soap with lotion soap. 1.4ml of each product was placed at the centre of a glass plate marked with a series of concentric rings. A second glass plate was then placed on top of the first to exert consistent pressure and cause the products to spread. The area covered was calculated as a function of time. The foam soap was shown to be eight times more spreadable than the lotion soap and to spread much more rapidly.

Energy Savings
The reduction in water use provided by hand washing with foam soap will also inevitably lead to energy savings. People do not tend to wash their hands in cold water, and heating water consumes energy. So, reducing the amount of water used will reduce the amount of water that needs to be heated. In fact, saving one litre of hot water saves approximately 13g of CO2. For our model office of 100 people washing their hands three times a day, using foam soap compared to lotion soap could save 254 kg CO2 a year or 1,027kWh.

The water savings reported above were produced spontaneously driven by product format. Further research was conducted to determine if greater reductions could be made through changing the hand washing method. Participants were asked to use Deb’s recommended hand wash method for foam soaps: dispense the foam lather direct on to dry hands and turning the tap on only when they wished to rinse the lather off. This method is enabled by the fact that foam soap is dispensed as an instant lather, without the need for additional water, and exploits the greater spreadability of the foam soap lather on dry hands.

This revised method reduced water usage to 951ml with the tap on for 13.5 seconds – 45% less than participants’ chosen handwashing method with lotion soap. It is worth noting that just over 20% of participants were already using this recommended method and 69% said it was as, or more, effective than their usual method.

If we once again assume people wash their hands three times a day at work, our model office of 100 people using this alternative hand washing method would save 56,000 litres of water a year compared to liquid handwash, or 36,000 litres each year compared to foam handwash using their usual method. In terms of heating the water this would save 724 kg CO2 or 2929kWh a year compared with lotion handwash.

Deb’s foam pump dispenses soap in 0.7ml measures compared with 1.0-1.2ml usually associated with lotion hand wash pumps. The significant reduction in the amount of foam soap dispensed is because the product volume is increased with air. It is Deb’s belief that 0.7ml of foam soap at a ratio of 1:10 with air is the optimum combination to be effective when compared to using traditional lotion soap. However, Deb wished to scientifically prove if this was the case.

Independent research carried out on behalf of Deb Group, compared the effectiveness of Deb Gentle Wash Lotion Soap – a lotion soap used in NHS hospitals – with Deb Rose Foam Wash – a typical example of Deb’s range of foam wash products – using the test method and requirement set out in BS EN1499:1997 Chemical disinfectants and antiseptics – Hygienic handwash.

Researchers asked participants to put their clean hands in a broth contaminated with E. coli K12, wash their hands with one of the soaps for 30 seconds and then rinse for 15 seconds. The number of test organisms was assessed before and after the hand wash products were used. The conclusion was that no significant difference was recorded between 0.7ml of the foam hand wash and 1.1ml of the lotion hand wash – confirming that equivalent efficacy from foam is delivered using 36% less product per hand wash.

In conclusion
Hand washing using foam soap offers a number of benefits compared with lotion soaps. People spontaneously use significantly less water when washing their hands with foam soap compared to lotion soap. This is achieved because foam soap is dispensed as an instant lather and is immediately more spreadable than lotion soaps which need water adding to create lather.

Water savings can be increased further by using Deb’s recommended foam soap hand washing technique – dispense, lather, tap on, rinse. The big question arising from this is how the behaviour change can be achieved and, in particular, how can the hand washing industry foster this change. This challenge is heightened by the fact that the hand washing method used by an individual is very much a sub-conscious activity.



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