Home hygiene: how clean should a home be?

Cleaning, vacuum cleaning, washing: home hygiene can help prevent potential health problems like infectious diseases.

That is because dirt is not simply dirt. Stains and house dust are often composed of organic material like food residue, small plant parts, human excretions, hair or dandruff. This provides a good breeding ground for mites, bacteria and yeasts and molds. A thin layer with microorganisms that are invisible to the naked eye quickly forms on frequently used objects like door handles and toilet seats.

Many microorganisms are harmless. But there can also be disease-causing pathogens among them that cause infectious diseases. Pathogens can get into a home via sick people, pets or pests such as mice and insects, for example. Domestic dust mites can also be a problem. While they are harmless, their droppings trigger allergies in some people.

Pathogens may also be found in foodstuffs. Bacteria like campylobacter and salmonella, or viruses such as noroviruses are often responsible for gastrointestinal diseases and food poisoning. It is therefore important to pay considerable attention to cleanliness and hygiene in the kitchen and when handling food. 
 
However, a completely “germ-free” environment in a home is neither possible or necessary. Water and normal household detergents or washing powders are usually sufficient to thoroughly clean the living space and textiles. Disinfectants should not be used on a regular basis, as they may be harmful to health and to the environment.

In private homes, microorganisms can be found in particular on surfaces, textiles and frequently used objects.

As a general rule, these are:

• Surfaces: among other things, work surfaces in the kitchen, basins, toilet seats, flush buttons, showers and floors
• Textiles: for example underwear, towels and bed linen, as well as cleaning rags
• Objects: such as handles, dishes and kitchen utensils
• Regular and thorough cleaning of the home with standard cleaning agents is sufficient to remove dirt and more than 90% of microorganisms from surfaces. It is advisable to more frequently clean locations on which microorganisms multiply rapidly. In particular, these are toilets, bathrooms and kitchens. Disease-causing pathogens might otherwise be easily spread to other areas via the hands.

In general, the following applies with cleaning:

• Common household detergents are sufficient. Antibacterial detergents or floor cloths have no health benefits.
• Cleaning the kitchen, bathroom and toilet with separate rags is recommended.
• It is best to dry rags in a well-ventilated location, because bacteria can multiply especially well in a damp environment. Furthermore, they should be changed often and washed at not less than 60 degrees.

Household detergents with antimicrobial effects?

A wide range of detergents advertise antimicrobial effects against bacteria, viruses and fungi. That can be recognized by indications like “pesticide”, “anti-bacterial”, “bactericidal”, “virucidal effect” or “removes 99.9% of all bacteria”.

However, a completely germ-free home is neither necessary nor sensible as a general rule. Most microorganisms in private homes are harmless and even beneficial to the human immune system.

For various reasons, products with antimicrobial effect are not recommended for homes. On one hand, disinfectant detergents can be an environmental burden and hazardous to health. On the other, the disinfectant effect of such household detergents cannot always be proven. Even if they are used as instructed, the concentrations and effective durations of such products are often not enough to completely remove microorganisms. When detergents with this kind of reduced effect are used regularly, or disinfectants used improperly, microorganisms may become impervious to the active ingredients.

The Federal Environmental Agency provides more information about home hygiene, when disinfectants are necessary and which agents are suitable.

More information about necessary and eco-friendly detergents is available from the consumer advice centers.

Necessary disinfection

Disinfectants should not routinely be used at home. Only in some cases, for instance when people with certain diseases or a severely weakened immune system are living in a household, can disinfection of surfaces and objects along with the hands be useful. When using disinfectants, follow the instructions on the packaging.

Many infections can already be prevented by thorough hand hygiene with water and soap. Hand sanitizer products should only be used under certain circumstances, for example if recommended by a doctor or if thorough hand-washing is not possible while traveling.

The following should be heeded when disinfecting the hands: apply an adequate amount of disinfectant to fully moisten the hands and wrists. Rub thoroughly for at least 30 seconds in the palms, backs of the hands, wrists and fingertips as well as between the fingers and knuckles. Ideally, rings, bracelets, wristbands or watches should be removed.

To ensure that a particular agent really has a disinfectant effect, the list of disinfectants at the Association of Applied Hygiene (VAH) is worth a look. This lists all agents that satisfy the requirements for hospitals.

Heat, moisture and food residue provide good conditions in a kitchen for bacteria and fungi to multiply rapidly. Depending on the species, microorganisms can survive from a few hours to several days on surfaces and objects. To prevent pathogens from spreading further via hands or food, all surfaces and objects should be kept clean. Dish detergents and simple household detergents are adequate for that.

Surfaces

• Make sure to wipe work surfaces, door or cupboard handles, sinks and cooker hoods regularly with as much warm water as possible and detergents, then dry them well.
• Paper towels are best suited to wiping up food residue.

Dishes and cutlery

• Clean dishes, cutlery and kitchen utensils with as much warm water and washing-up liquid as possible or in a dishwasher at a minimum of 60 degrees. 
• If washing by hand, do this as soon after the meal as possible, because germs can breed very rapidly at room temperature.

Cleaning utensils

• For dishes, work surfaces and floors, separate cleaning cloths should be used.
• Spreading out cloths, hand and dish towels for drying is recommended, as is regularly washing them at a minimum temperature of 60 degrees.
• Plastic dishwashing brushes should be cleaned regularly in the dishwasher and replaced every now and then.
• For hygienic reasons, dish sponges are not so suitable. If they are nonetheless used, it is important to replace them regularly.

Waste

• Empty waste bins often and wash them out at least once a week with warm water and detergent.
• Waste disposal bags with an anti-bacterial effect are not necessary from a hygienic standpoint.

Refrigerator

• The correct maximum temperature for a refrigerator is 7 degrees, but under 5 degrees is better. The ideal temperature of a freezer is -18 degrees.
• Cool air can circulate better if the refrigerator is not packed full.
• It is advisable to clean the refrigerator several times a year, and to defrost freezers occasionally if these do not have an automatic defroster. Information about this is available in the manufacturer’s specifications.

Generally ensure good food hygiene and cleanliness in the kitchen. Regular handwashing is also important.

Bathroom hygiene is especially important. A great number of microorganisms are present in feces, some of which can cause illness. After a bowel movement, these pathogens can be easily spread via tiny stool residues. Furthermore, microorganisms breed well in a warm and humid climate.

Along with general recommendations for cleaning, the following should be observed in a bathroom:

• Use a separate sponge or cloth for cleaning the toilet.
• Also regularly wipe down door handles, light switches and other surfaces that are touched with the hands.
• After a bath or shower, ventilate well to let moisture out.
• Use multi-layered toilet paper so that the hands make as little contact as possible with stool residues.
• After a bowel movement, wash hands thoroughly with soap for at least 20 seconds.

The Federal Center for Health Education (Bundeszentrale für gesundheitliche Aufklärung – BZgA) provides more information about toilet hygiene on the website infektionsschutz.de (in German).

Dirt on clothing and textiles is not just dirt. Grime, stains and odors are less harmful than human excretions, which can contain germs. Germs are found predominantly in underwear, socks, bed linen and towels. But not every garment contains germs that need to be removed by washing.

How well pathogens are removed depends on the washing temperature, among other things:

• 30 °C wash: This temperature is especially suitable for cleaning slightly dirty outer garments like pants, T-shirts and sweaters, because these are rarely contaminated with excretions.
• 60 °C wash: At this temperature, most pathogens from underwear, towels, bed linen, cleaning rags and dishtowels are removed.
• 90 °C wash and disinfection: Wash cycles at these temperatures or with additional disinfections usually only make sense with severely infectious diseases like gastrointestinal and yeast fungus diseases or if the household includes people with immune deficiency. A hygienic rinse is not advisable for regular use. The physician in charge will advise if a disinfection is necessary.

The washing powder and washing program used play a role. Colored washing powder or heavy duty liquid detergent do not have any germicidal effect since they do not contain any bleaching agents. Heavy duty detergents containing bleach, in powder form and as a tab, kill bacteria at temperatures as low as 30 degrees. But they also make the colors of textiles less intense.

Under certain conditions, germs can breed in washing machines, for example if clothes heavily contaminated with human excretions are washed in a short cycle at 30 degrees and without bleach.

The consumer advice center (“Verbraucherzentrale”) provides more information about choosing washing powders.

House dust forms quickly on seldom-used surfaces such as skirting boards, shelves and television sets. It can adversely affect health for various reasons.

On one hand it contains mites that cause symptoms for people with a dust allergy. On the other, toxic substances may accumulate in house dust. They come for instance from automobile exhaust, paints, dyes and impregnation materials, or furniture and carpets. Some of these substances can cause cancer. If the dust is breathed in over a long period of time and in high amounts, this may be harmful to health.

The best remedy for removing dust from a home is 
ventilation: more dust leaves the home than enters it this way. Moisture and other chemical substances are also removed from a home this way and the risk of molds forming is reduced.

Regular dusting and vacuum cleaning moreover helps. Damp cloths or special anti-dust cloths are suitable for dusting since they bind dust well. For vacuum cleaning, devices with an additional filter such as a HEPA filter are suitable. This prevents some of the vacuumed dust getting back into the ambient air.

The German Skin and Allergy Aid Association (Deutsche Haut- und Allergiehilfe e.V.) provides further information about how dust and allergens can be reduced in a home and recommendations about suitable products and devices.