Science in the box

Personal hygiene blossomed around 1915. This was not caused by a single phenomenon. Multiple parameters played a role, such as improved housing and nutrition conditions as well as improved sanitation and personal hygiene. The proportion of urban homes served by "safe" water distribution systems increased. Soap manufacturing jumped dramatically, bathrooms and laundries were constructed and people were encouraged to wash frequently, both their bodies and their clothes. Washing and rinsing brought the concentrations of microorganisms below a dangerous level. Boil washes and use of improved detergents revolutionized laundering. Since then, most societies have witnessed a long history of continuous hygiene improvements.

Today, personal home hygiene has been dramatically improved and the effects are impressive: life expectancy has increased nearly 40% while infant mortality rates show a 60% decline from 1950 to 1995. Good hygiene habits and improved laundry and cleaning products have, in part, been behind this trend in healthy living.

The Age of Personal Hygiene
An analysis of historical data by Professor V. W. Greene, University of Minnesota in the United States, suggests that the dramatic decrease in global infant mortality, from 179 per 1,000 in 1850 to 50 per 1,000 in 1940, can be attributed to a temporal association between disease incidence and personal hygiene status. Analysis of a common factor - cleanliness level as reflected by soap utilization - remains a consistent health determiner.

An analysis of data from 120 countries indicates that there is an inverse relationship between infant mortality rates in different countries and the respective per-capita soap consumption—an excellent index of personal hygiene status. While these are not simple cause-and-effect related phenomena, this correlation indicates how personal hygiene changes have been an important contributor to improvements of human health and life expectancy during the last century.
The Age of Disinfectants
Together with soap, the recent use of disinfectants in the home has had an important effect on us. The rationale for combining disinfectants with cleaners was to help achieve and maintain hygienic living conditions. Disinfectants though are no longer an aggressive "bomb". While the classical harsh hospital grade disinfectants (such as phenols) may have a low human and environmental safety profile, disinfectants meant for household use are less aggressive as the microbial load is lower than that of a hospital.
Related Scientific Publication
Greene, V.W. Personal Hygiene and Life Expectancy Improvements Since 1850: Historic and Epidemiologic Associations. American Journal of Infection Control. 29 (4), p. 203, 2001.

What Are Antibacterial Cleaning Products? Antibacterial, or antimicrobial, cleaners are specially formulated with antibacterial actives to control bacterial growth on surfaces. The controlling action may be bacteriostatic (inhibition of bacterial growth) or bactericidal (killing the bacteria). Based on proprietary surfactant technology, P&G antibacterial dishwashing products are specifically designed to be effective against bacteria.

The Uses of Antibacterials

Antibacterial products have generated some controversy. Some groups argue that one should not try to make the home a sterile environment, and we agree with this.

However, antimicrobials were not created with the purpose of making an environment sterile. Rather, they were formulated for consumers who want to have an antimicrobial product on hand for certain jobs, such as washing hands in the kitchen or bathroom, or for cleaning kitchens, bathrooms, doorknobs and other areas where the risk of microbial contamination is higher.

People who take care of the ill or elderly or infants in day-care centres may use antimicrobial cleaners more often, because they know from experience that they have to be more careful about keeping microbial contamination under control.

The Care of Kitchen Sponges and Dish Cloths

Unless sponges and dishcloths are replaced, laundered or disinfected regularly, they provide a breeding ground for microbes that make a home in their pores. These microbes use food residues for their growth. Within a week of use, the sponge may contain billions of bacteria, as evidenced by its smell and feel. If we use such a sponge for wiping surfaces, we are spreading bacteria. If the sponge is contaminated with pathogenic bacteria, spreading them makes it easier for other people to pick up the contamination and possibly become ill.

P&G’s Fairy Antibacterial Action dishwashing detergents have been developed to maintain sponge quality from a microbiological standpoint. After washing up, rinse the sponge under running tap water and squirt a small amount of undiluted detergent onto the sponge. The product in the sponge inhibits bacterial growth and prolongs the life of the sponge.

To test the efficacy of surface cleaning and dishwashing products in the kitchen, Procter & Gamble had equipped an experimental kitchen experimental kitchen in the early 2000s in collaboration with Institut Pasteur in Paris, France. In this kitchen, consumer habits were reproduced under controlled conditions, allowing us to study them and better identify bacterial hotspots.

Testing and Evaluating Antibacterial Efficacy

Because bacteria are invisible to the naked eye, the controlling action of antibacterial products is imperceptible to consumers. P&G takes the responsibility of bacteria control very seriously. Our researchers make sure that our products have the expected efficacy against microbes and that they will meet efficacy requirements in the countries where they are sold.

In short, P&G researchers formulate products to meet high standards by first using stringent screening assays in the laboratory. Next, the selected formulations are subject to more stringent laboratory-based tests, as recommended by the European Normalization Commission [Comité Européen de Normalisation, CEN]. Products are then subjected to more realistic in-use tests, to confirm product efficacy against microbes and to guarantee effectiveness under real-life conditions.

The type of efficacy test depends on the claim made on the product. In general, P&G follows the European guidelines for evaluating the efficacy of antimicrobial products. This involves testing the product in the laboratory, using microbes in suspension, to assess their intrinsic biocidal potential. If a satisfactory test result is obtained in the laboratory, the product is subjected to a more stringent test, using microbes that are added to and then dried onto the appropriate carrier surface(s).

Today consumers have shifted, and continue to shift, to doing their laundry at wash temperatures of 40˚C and below. This is due to increasing garment care label instructions for cold water washing and because of consumer care to avoid mixed/dark coloured items dye fading. More and more consumers also seek to reduce energy and monetary costs and are willing to make an effort towards more sustainable washing habits.

There has been a question raised if this recent trend in washing at cooler temperatures could lead to increased bacterial risks remaining on laundry after the wash. No health effects have been observed with these consumer habits. In Spain and Japan, for example, where people have been doing their laundry with unheated cold water for decades, there has been no reported increase of public health issues.

While cleaning garments at 40°C and below contributes to soil removal through mechanical action and surfactant aid, it does not provide total removal of bacteria. Under normal circumstances (i.e. no extreme soiling and no health issues) this will not create any health issues.

Most bacteria are indeed normal inhabitants of the human skin and guts and are harmless or even beneficial for humans. Only a small number are detrimental to health - these are called pathogenic. But washing at low temperature or below is safe for most of your normal loads. That is why the Center for Disease Control in the USA recommends regular washing cycles for normal laundry.

However there are certain high risk groups or situations where washing at cooler temperatures may not be sufficient. To investigate this further, In addition, P&G has consulted with public health experts to assess any risks from recent cleaning trends. It was concluded that in most domestic situations, there is no significant risk. In situations with specific vulnerable populations, they could be added reassurance by either washing at higher temperatures or using an anti-bacterial laundry additive. This is explained in the next section with tips for hygienic laundry.

Today many consumers have shifted, and continue to shift, to wash temperatures of 40˚C and below for many loads. No negative health effects have been observed with these consumer habits and washing normal everyday garments at low temperatures will remove germs, give good cleaning results and save energy.

In normal, low-risk household situations Some clothing items may have higher levels of bacteria. This is the case of heavily soiled garments like underwear and dish cloths. Fabrics containing bodily fluids or those in contact with pets may also require deeper cleaning. In such cases, washing at higher temperatures (60°C) and using laundry powder or tablet products with an oxygen bleach is advisable. Alternatively, one can ensure their laundry bacteria are removed while still washing at cooler temperatures by using an effective laundry additive like Ariel Stain Remover. This is important when the care label requires washing at lower temperature.

In high-risk, vulnerable situations
When someone in the home or within the professional workplace is ill or more vulnerable to infection, like the elderly, babies (whose immune system does not develop until a few months after birth), pregnant women or immuno-compromised people, it is important to use products and procedures that fully protect against bacteria. This is also the case of health professional uniforms that need to be washed at home.

Steps to be taken include:

• Segregating laundry – e.g., not washing items with high levels of bacteria with items used by people with impaired immunity.
• Using a laundry bleach-containing detergent and wash at a higher temperature (60°C).
Or
• Using an effective specialist laundry additive product following its usage instructions designed to remove bacteria at lower temperature when washing at 30°C or lower temperatures.

Intuitively, when dealing with highly soiled loads that require additional disinfection, consumers usually tend to increase the wash cycle temperature to achieve the best results.

But by heating the water, up to 80% of the electricity for the machine wash is used. Energy consumption and CO2 emissions can be decreased by lowering the wash temperature. For example:

• decreasing from 40°C to 30°C, can save up to 30% of electricity; and
• decreasing from 30°C to 15°C, can save up to 50% of electricity

But consumers do not need to compromise their laundry performance by switching to lower wash temperatures, even for highly soiled loads. That is why P&G focused on developing an effective laundry additive, Ariel Stain Remover, to complement the detergents formulation whenever deep cleaning action is sought, allowing to reach the desired laundry experience while still washing at 30°C.