Considerations regarding the use of chlorine in infection control within general medical services
Environmental sanitation is just one of several methods recommended for reducing the transmission of germs among patients and medical staff. Cleaning and disinfection, along with other infection control measures, such as hand hygiene and isolation precautions, are important ways to help stop the spread of pathogens and control infections in medical facilities. This article primarily focuses on infection prevention and control practices in areas where chlorine-based solutions are mainly used for disinfection, but are not standardized and may vary significantly in terms of solution concentration.
Description of chlorine use as a disinfectant
Chlorine solutions (Cl2, NaOCL, Ca[OCl]2, ClO) have been widely used as disinfectants and antiseptics since the 19th century. Studies have recently been published on the past use of these compounds for environmental and healthcare infection control in the context of preventing the spread of the Ebola virus. Chlorine solutions are oxidative chemicals and have broad-spectrum activity against a wide variety of microorganisms, from viruses to protozoa.
During Ebola epidemics, 0.5% chlorine solutions (this would generally be equivalent to a 1:10 dilution of household bleach) were used for environmental surface disinfection, while a 0.05% solution was used for hand hygiene. Non-governmental organizations routinely provided hospitals and drinking water supply programs with sodium dichloroisocyanurate (NaDCC) for use in preparing disinfectant solutions, as well as other chlorine-based products for use in the disinfection process. There have also been some projects in Africa that involved the electrolytic creation of sodium hypochlorite from brine solutions (primarily for disinfecting drinking water, e.g., CDC Safe Water, UNICEF Safe Water).
Chlorine solutions (sodium hypochlorite) are produced in different concentrations in different parts of the world, and the strength of the solution can vary between 2% and 12% NaOCl. Because there is such great variation in the concentration of products available in some countries, it is strongly recommended that the concentration of the chlorine product be evaluated before use. KLINTENSIV® KlinoChlor Tabs – effervescent chlorine tablets
Validation of chlorinated products
If there is doubt about a product, it is recommended to determine the chlorine concentration through chemical analysis (e.g., DPD [N,N-diethyl-p-phenylenediamine] color-change test kits, amperometric titration for residual chlorine, commercially available test strips, or analytical sticks). Reagent-grade water will also be needed to make 1:100 and 1:1000 dilutions of the prepared solution to perform the tests.
Considerations regarding chlorine use
There are no published studies that have tested the efficacy of chlorine-based products against ebolaviruses. However, chlorine solutions are known to be effective against a wide range of viruses.
The wet contact time is the period during which a surface being disinfected must remain wet with the disinfectant. The wet contact time for chlorine varies between 2 minutes and 10 minutes, depending on the microbe/virus. For wet contact times longer than 10 minutes, it may be necessary to reapply a chlorine solution or another acceptable disinfectant. When treating surfaces potentially contaminated with ebolaviruses and other bloodborne pathogens, a 10-minute wet contact time with a 0.5% to 0.6% chlorine solution should be allowed.
Chlorine solutions and other disinfectants are inactivated by the presence of organic matter (blood, other proteinaceous matter, dirt), heavy metal ions, low temperature, or ultraviolet irradiation. Both the WHO and CDC recommend cleaning with detergent and water before applying the disinfectant. This will help prevent the inactivation of the disinfectant by organic matter. KLINTENSIV® – Concentrated disinfectant detergent
Chlorine solutions should not be used for routine hand hygiene, as they will eventually damage the skin. Soap and water or alcohol-based hand rubs are preferred. Hand sanitizer solutions offer multiple benefits compared to the use of water and soap in terms of skin tolerance, treatment adherence, and, especially when combined with the use of gloves, overall effectiveness against a wide variety of healthcare pathogens. However, if hands become visibly soiled, use soap and water, not sanitizer solutions.
Strong or weak chlorine solutions can be prepared from several different types of available products. To be effective in infection control, solutions with a concentration containing either 0.5%-0.6% (5000-6000 ppm) or 0.05-0.06% (500-600 ppm) of available chlorine are required, depending on the intended use. Household bleach is different from either Ca(OCl)2 (e.g., HTH, chlorinated lime) or locally prepared "bleach" products commonly found in supermarkets. It is very important to understand which product is being used to make a solution, because the amount of dilution required for a product to be effective varies.
Other important considerations
Chlorine-based solutions must be prepared daily, as they are light-sensitive.
Most chlorine-based products require the removal of organic soil before use, specifically cleaning before disinfection. CLOR2KLIN® – Chlorine-based disinfectant, effervescent tablets
The disinfection step requires a wet contact time (the amount of time the disinfectant must remain on the surface to be effective).
The smell of chlorine does not necessarily indicate an appropriate concentration of the solution, as the odor can be detected even at extremely low concentrations.
Attention! Chlorine solutions are corrosive and can pit metal and damage skin.
Preparing chlorine-based solutions for infection control
When preparing chlorine-based solutions, keep in mind that there is no simple dilution that can be used to reach the optimal working concentration. How much dilution is required depends on the type of product available. The following guidelines can be used when preparing chlorine solutions.
Before use, consult the safety data sheet of the specific product used and check the section for the appropriate personal protective equipment to avoid chlorine exposure.
Prepare a 0.05% chlorine solution (approximately 500 ppm) by adding one tablespoon of HTH granules to 20 liters of clean water and mix for 10 seconds.
Prepare a 0.5% hypochlorite solution (5,250 ppm) by adding 10 full tablespoons of HTH granules to 20 liters of clean water. After mixing, wait 30 minutes to allow all the Ca(OCl)2 granules to dissolve.
As an alternative, the following methods can be used to prepare chlorine solutions from either sodium hypochlorite (liquid) or calcium hypochlorite.
Alternatives for chlorine-based solutions
As can easily be observed, the use of chlorine is not the most user-friendly method of disinfection. Effective and faster alternatives can be successfully used in hospitals. These include:
- Hydrogen peroxide-based disinfectants: DESOGEN® AERO
- Alcohol peroxide-based disinfectants: GLUTANOL® RTU for surfaces and instruments
- High-level concentrated disinfectant: GLUTACIDE®
- KLINTENSIV® concentrated disinfectant detergent
