Status quo of disinfection:
Safety for users and the environment
The most important foundation of medicine is the high standard of hygiene, the central importance of which becomes particularly apparent in times of pandemics and with the increasing development of microbial resistance. In the healthcare sector, infection prevention serves to ensure patient safety and protect employees, while in companies it serves to ensure product and consumer safety. Hygiene plans adapted to the respective institution are legally binding in Austria and Germany and require the use of effective disinfectants. Considering the large number of institutions in the health care sector and extending this to the manufacturing food industry and pharmaceutical companies, correspondingly high quantities of disinfectants are indispensable for or before certain work steps.
At first glance, chemical disinfection and environmental protection seem to be two diametrically opposed areas. Substances that specifically eliminate microorganisms for the protection of humans can also kill environmentally relevant microbes of various kinds via wastewater. In addition, some disinfectants contain molecules, such as environmentally stable aldehydes or quaternary ammonium compounds (quats), which accumulate in the environment and, depending on their concentration, can have long-term toxic effects on aquatic organisms.
Focus on hand disinfection
Hand washing is often assumed to be the more skin-friendly version and disinfectants the more "aggressive" measure of hand hygiene. However, during the pandemic in particular, it was shown that excessive hand washing with soap damages the skin barrier and thus promotes the development of irritative-toxic hand eczema. Consequently, hand disinfection is preferable to frequent washing. Unlike surface disinfection, however, skin-compatible active ingredients must be used, as only these are tolerated by the user on a correspondingly regular basis. A central element of infection prevention is the widespread availability of hand disinfectants which guarantee comprehensive protection against infection while at the same time ensuring a high level of environmental compatibility.
Products containing sodium hypochlorite (NaOCl) are advertised as "particularly gentle, biological and natural". However, this active ingredient is highly toxic and chemically reactive. It is a surface disinfectant. It is not approved for hand disinfection in most countries.
Chemically pure alcohols - propanol or ethanol - in high concentrations, on the other hand, exhibit broad efficacy against bacteria, fungi and, in some cases, viruses by immediately and irreversibly denaturing and thus destroying the proteins of the microorganisms.
The alcohols are very well tolerated on intact skin and show three main advantages: they act very quickly, dry within 15-30 seconds without leaving residues, and show no harmful or irritating residues for humans or the environment. The development of resistance to propanol or ethanol can be ruled out.
Skin degreasing is prevented by skin care additives such as dexpanthenol and vitamin E. They are harmless to the skin. They are harmless to the environment, whereas glycerin is produced in an energy-intensive petrochemical process, i.e. is petroleum-based.
In particular, the benefits of ingredients declared as "remanent active ingredients" (e.g. chlorhexidine, triclosan, mecetronium ethyl sulfate, orthophenylphenol), i.e. active ingredients remaining on the skin, must be critically questioned.
For chlorhexidine, for example, bacterial resistance formation, induction of cross-resistance to reserve antibiotics as well as skin irritations and anaphylaxis have been described. In addition, the molecule remains stable in wastewater. Triclosan can also cause contact allergies and is highly toxic to aquatic organisms. In 2016, it was therefore banned in the U.S. as an environmental and health hazard in rinse-off hand and body cleansing products.
The Commission for Hospital Hygiene and Infection Prevention (KRINKO) therefore advises against: "Preparations with added antimicrobial remanent active ingredients are not recommended, as their addition does not improve efficacy but increases the risk of side effects."
Focus surface disinfection
For the disinfection of surfaces and instruments in particular, numerous parameters such as material compatibility, the required exposure time and/or the required spectrum of activity must be taken into account.
Internationally, there is a trend towards biodegradable cleaning agents, such as the use of enzymes. Furthermore, disinfectant wipes made of sustainable materials, which until now have often been made of PET (polyethylene terephthalate) or PP (polypropylene), are increasingly being offered. For the professional sector, surface disinfection products based on peracetic acid (PAA) - which decomposes into oxygen, water and vinegar after use - or active oxygen are increasingly being developed. They have a particularly high performance spectrum (virucidal, sporicidal), are well compatible with many materials and leave no long-lasting toxic residues.
A valuable sustainable addition would be the prompt switch to upcyclable or recyclable disinfectant containers for hand and surface disinfection and their return by the manufacturers.
Transparent presentation (in German and English) of the hazard potentials of commercially available disinfectants. Enables the selection of a disinfectant that poses the least risk to staff, patients and the environment.
For routine disinfection measures in the field of human medicine.
Robert Koch Institute (RKI), Germany
List of tested and approved disinfectants and disinfection procedures for officially ordered disinfection in the human area.
For routine disinfection measures in the human medical field.
Tested in accordance with the EU Biocide Regulation, efficacy proven by expert opinion. The listed biocidal products cover the human sector, veterinary sector and food production.
Listing of active substances tested and approved in accordance with the requirements of the Biocides Regulation.
© OÄ Dr. med. univ. Mahitab Khalifa-Paruch, Vienna, 11/2021