Disinfectants are often tested against one or more international standard to show that they are effective. The UK and Europe use standards described in the EN system and products that meet them are required to carry details on their packaging and in their documentation. Testing is carried out by independent and accredited laboratories under strict conditions. This provides assurance that a product has been verified to meet any particular standard.
There are in fact many EN standards covering a wide range of industries and applications, including cleaning and hygiene. Separate standards cover a product's ability to kill viruses, bacteria, spores, fungi, and other pathogens. Tests are completed in ?laboratory conditions? with products tested at specific concentrations, temperatures, and clean and dirty conditions, against reference pathogens.
Each standard requires a disinfectant to remove a predetermined amount of a specific pathogen ? or class of pathogen - within a certain time. This level of disinfection is typically given as a reduction in the number of pathogens expressed as a logarithmic number. Most disinfection standards require log 4 (equal to 99.99% or 10000-fold) or log 5 (99.999%, 100000-fold) reduction. By comparison, retail or consumer products are rarely tested to these exacting standards and in any case will generally claim lower (eg 99.9 or 99.99%) reduction rates.
It is not unusual for a professional product to meet more than one standard. However, manufacturers can only claim a product meets a particular standard if it has been tested. Just because a product meets one standard does not mean it will (or can) meet any others.
One of the most important standards related to the Covid-19 pandemic is EN14476. This specifies a test method and the minimum requirements for virucidal activity of chemical disinfectants and antiseptics. It applies to products that are used in medical applications including hand rubs, handwashes, instrument disinfection by immersion, surface disinfection by wiping, spraying, flooding or other means, and textile disinfection.
EN14476 is important at the moment because it includes a specific test against enveloped viruses (in the form of the vaccinia virus). This is the same type of virus as SARS-CoV-2 that causes Covid-19. Enveloped viruses are generally easy to kill so disinfectants which meet the requirements of EN14476 (specifically the ?fully virucidal? or ?virucidal against enveloped viruses? tests) should be effective against SARS-Cov-2.
In practice, EN14476 covers a fairly broad range of potential products and applications. Because of this each product has to be tested against the standard for the applications for which it is intended. These sub-tests have specific criteria but they are always based on the core EN14476 standard. This is why when manufacturers state their product meets the standard, they will usually include details of the specific sub-tests that the product has passed.
EN14476 stipulates that a product must deliver a ?log 4? reduction in the amount of virus. This is the same as a 10,000-fold or 99.99% reduction and must be achieved within specific timeframes, depending on the type of product being tested. This is generally known as the contact time: the length of time ? in seconds or minutes - the disinfectant must remain wet to achieve the required level of disinfection. Hand rubs, for example, must work within at least 30 seconds but no longer than two minutes, reflecting the need for speed and convenience with hand hygiene. Surface disinfectants must meet the standard in less than five or sixty minutes, depending on the specific test criteria. Manufacturers can claim their products work faster as long as they can provide evidence.
It is important to understand that all disinfectants permitted in healthcare will meet the standards they have been verified against as long as they are used correctly. The main challenge facing cleaning teams is that liquids dry out. This will depend on many factors. Warmer room or surface temperatures, lower air humidity, and lower atmospheric pressure all encourage any given product to dry faster. Formulations containing alcohol and some other less common active ingredients usually dry faster than those that do not. Many disinfectants dry out in three or four minutes in typical settings when applied using conventional techniques.
In these situations, it can be difficult to keep a surface wet for the minimum contact time. Often the only practical answer is to reapply the product so that the surface remains wet. Another option might be to apply more product in the first place so that it takes longer to dry. These options are rarely practical and can be time-consuming and costly because more product is needed to meet the required outcome. An ideal disinfectant will therefore have a contact time that is shorter than its drying time.
Diversey products that meet EN14476 include the Soft Care Des E, Soft Care Med H5, and SURE Instant Hand Sanitizer hand rubs. Surface disinfectants in the Oxivir range and laundry products in the Clax range also meet the standard under their relevant test conditions. In fact, most of Diversey's hand and surface disinfectants meet the standard for virucidal protection when used correctly.
Each is available in a range of formats to promote the flexibility and convenience that will encourage proper and frequent use. Suppliers should be able to show evidence their products meet relevant disinfection standards and provide additional supporting documentation such as user guides and wall charts that encourage frequent and proper use.
