Counting On Contact Times

Disinfectants are widely used in healthcare and other settings to kill the microorganisms and pathogens that can cause infections and illnesses. The length of time a particular disinfectant must remain on a surface to do its job effectively is usually known as the contact time but is sometimes called the dwell or kill time.

Contact time is important because different types and concentration of disinfectant will work at different speeds for each pathogen. And some pathogens are harder to kill than others. C.diff spores, for example, generally take longer to kill than the viruses that cause colds, Norovirus or the flu when using the same disinfectant at the same concentration. In practice contact times can be as low as 30 seconds or as high as ten minutes or even longer depending on specific product, pathogen and setting.

A disinfectant must generally remain wet so that its active ingredients can stay in contact with the surface being treated long enough to do their job. If the liquid dries too quickly the disinfectant will become inactive and ineffective. When this happens, some pathogens survive on the surface and remain a potential source of contamination and infection. Further applications are required to maintain the “wetness” for the right amount of time. That is expensive, inefficient and wasteful, especially in settings where the people responsible for disinfection tasks have lots of other things to get on with.

It follows that the best disinfectants are those with contact times shorter than the time they take to dry because these only need one application. Alcohol-based disinfectants are often very effective but they do tend to dry quicker than water-based formulations. Sometimes they dry faster than the contact time which means repeat applications are necessary.

Water-based products (including those containing hypochlorite or hydrogen peroxide) are more likely to remain wet for the right contact time after just one application. But if the contact time is too long these too can dry before they can disinfect properly. Adding larger amounts of liquid in the first place is not usually practical but is also wasteful and inefficient. Disinfectants that work quickly and only need one application are also less likely to be misused or result in non-compliance than products that need repeat applications.

Disinfectants certified for use in healthcare and food settings will generally have passed one or more recognised industry standard “EN” test. They will also have labels and documentation that includes details of their contact times. Reputable suppliers will offer a choice of products and be able to recommend the right one for any given application. They will also be able to supply proper evidence and statutory documentation to support their claims and offer user guides and other training aids to promote compliance and simplicity in use.

Sustainable Hand Hygiene

Although food safety will be a priority, businesses serving food face many other regulatory and market-driven pressures, not least to adopt processes that are more sustainable. Choosing the right kitchen hygiene products can contribute to both areas.

Food safety is always critical. The majority of food-related illnesses are caused by bacteria. According to the Food Standards Agency, campylobacter causes the most cases – over 250,000 a year – of food poisoning in the UK with E.coli and salmonella also affecting large numbers. Each of these causes unnecessary suffering as well as disruption and loss of reputation to any business whose staff or customers become ill. Listeria monocytogenes causes the most food poisoning deaths although the numbers are very small. Around 40% of all food poisoning outbreaks are the result of poor hand hygiene and cross contamination.

The average person’s hands can carry more than 3000 different types of bacteria and about 100,000 can live on each square centimetre of skin. Many of these are completely harmless but just a few of the wrong type can quickly lead to illness. One bacterium can multiply to over four million in eight hours, so it is clear that keeping hands clean is critical to preventing the spread of infections.

We have known this for a long time and all learn as children to wash our hands before eating and after going to the toilet. Despite this it seems many people continue to ignore this most basic act of personal hygiene.

Hand hygiene products for food service need to be effective yet gentle because they will be used frequently during the day. Modern formulations incorporate highly effective biocidal ingredients as well as emollients that help preserve the skin’s natural protective barrier and keep hands soft. They should not include perfumes to avoid tainting food. Leading suppliers offer a choice and are able to recommend the best option for any particular setting.

Another key issue facing food service businesses is to make their operations more sustainable by using less water, energy and cleaning products. There are lots of ways of doing this without compromising the quality of the food or the safety of customers and staff. Replacing conventional cleaning warewashing and laundry products with innovative formulations that are effective at lower temperatures can be a simple first step.

A further option is to replace ready-to-use or traditional bulk products with ultra-concentrates. Used with simple and convenient wall-mounted or portable dosing and dilution control equipment, ultra concentrates support sustainability by enabling safe, simple and consistent high-performance cleaning while minimising wastage, packaging and chemical miles. Products available as ultra-concentrates cover all key kitchen hygiene tasks including hand hygiene.

Recently, cleaning product suppliers have devised novel formulations that utilise environmentally-friendly ingredients to provide further choices to customers who want to demonstrate the highest levels of environmental responsibility. These are typically derived from plant-based renewable resources such as by-products originating from sugar beet, maize and other common foodstuffs. When products like these are available in ultra-concentrate formulations they provide an additional sustainability benefit.