Disinfectants and sanitizers are chemicals that reduce, destroy, or inactivate microorganisms including bacteria, fungi, yeast, and viruses. Disinfectant and sanitizing claims are regulated by the EPA in the US, and data demonstrating antiviral activity must be generated to support these claims.

These products play a critical role in the prevention of diseases and can be applied to surfaces by a variety of methods. These application methods can include liquids applied by mopping or soaking, trigger/pump or aerosol spray, or pre-saturated towelettes. These products can be used on hard surfaces as well as soft surfaces, and may also contain residual properties or be used in antimicrobial coatings.

For more than three decades, Element has supported product formulators, manufacturers, and marketers to assess the efficacy of sanitizing and disinfectant products against microorganisms and viruses. Our consultative regulatory and scientific teams are committed to delivering the highest quality data for established methods. We can also develop custom protocols to meet your specific disinfectant/sanitizer testing needs. To explore a partnership with Element, contact us today.

Suspension based testing

ASTM E1052 Standard Practice for Efficacy of Antimicrobial Agents Against Viruses in Suspension - This practice is used primarily as a screening tool to assess efficacy of a product. It may also be used for hand sanitizer type products. In this method, an aliquot of the test substance is inoculated with the test virus and held for the requested exposure time(s). At each predetermined exposure time an aliquot is removed, neutralized by serial dilution, and assayed for viral infectivity by an assay method specific for the test virus. Appropriate virus, test substance cytotoxicity, and neutralization controls are run concurrently. The percent and log reduction in viral infectivity are calculated as compared to the corresponding virus control. Typically, for a product to be considered as being efficacious, least a 1 log reduction (90.0%) of the virus should be demonstrated. For registration with US EPA against a hard surface, a product must demonstrate a 3 log reduction (99.9%) following a hard surface test method.

Hard surface testing

ASTM E1053 Standard Practice for Efficacy of Virucidal Agents Intended for Inanimate Environmental Surfaces- liquid/spray/towelette - In this method, a glass Petri dish (“carrier”) is inoculated with a representative test virus and the virus is dried onto the carrier. The inoculated carrier is exposed to an aliquot of the use dilution of the test substance (liquid products), or to the amount of spray released under use conditions (spray products) or is wiped per use instructions (pre-saturated towelette). The carrier is held for the requested exposure time at the requested exposure temperature. Following exposure, the contents of the carrier are neutralized and serial dilutions of the neutralized test substance are performed. The dilutions are then assayed for viral infectivity by an assay method specific for the test virus. Appropriate virus, test substance cytotoxicity, and neutralization controls are run concurrently. Typically, most regulatory agencies require at least a 3 log reduction of the virus in order to claim efficacy on a hard surface.

Virucidal Efficacy of a Disinfectant for use on Inanimate Environmental Surfaces - Surrogate Viruses- liquid/spray/towelette - ASTM E1053 standard practice is used for testing, however two replicate carriers are required to be tested for the virus control and test lots. Surrogate viruses accepted by US EPA are:

Virucidal Efficacy Validation of a Disinfectant Used to Clean and Disinfect the Exterior Surface of Blood Glucose Monitoring Devices Utilizing Duck Hepatitis B virus as a Surrogate for Human Hepatitis B Virus - Each material, compromising the exterior of the device, is inoculated with the test virus and the virus is dried. The inoculated materials are wiped with the disinfectant per the Sponsor instructions and held for the exposure time listed on the disinfectant label at the requested exposure temperature. Following exposure, the inoculated materials are individually neutralized and serial dilutions of the neutralized test substance are performed. The dilutions are then assayed for viral infectivity by an assay method specific for the test virus. Appropriate virus, test substance cytotoxicity, neutralization, and negative (cell) controls are run concurrently. The US FDA requires complete inactivation of the virus in all dilutions assayed.

Virucidal Efficacy of a Disinfectant for use on Inanimate Environmental Surfaces- Electrostatic Sprayer Application - A glass Petri dish (“carrier”) is inoculated with a representative test virus and the virus is dried onto the carrier. The inoculated carrier is exposed to the amount of spray released under use conditions (spray products) at minimum and maximum distances. The carrier is held for the requested exposure time at the requested exposure temperature. Following exposure, the contents of the carrier are neutralized and serial dilutions of the neutralized test substance are performed. The dilutions are then assayed for viral infectivity by an assay method specific for the test virus. Appropriate virus, test substance cytotoxicity, and neutralization controls are run concurrently. Generally, most regulatory agencies require at least a 3 log reduction of the virus in order to claim efficacy. EPA testing and regulatory submission information can be found here.

Soft surface testing

Virucidal Efficacy of a Laundry Additive - In this method, a series of fabric swatches are inoculated with the test virus and are dried. The swatches containing the dried test virus are placed inside fabric-wrapped spindles and are treated in a simulated laundry apparatus. Following treatment, the swatches and a sample of the wash water are removed, neutralized and are assayed for viral infectivity by an assay method specific for the test virus. Appropriate virus, test substance cytotoxicity, and neutralization controls are run concurrently. Typically, for efficacy to be demonstrated at least a 3 log reduction must be demonstrated on the treated fabric swatches and in the treated wash water as compared to the virus control.

Virucidal Efficacy of a Disinfectant for Use on Soft Surfaces- liquid or spray products - A fabric (soft) surface (“carrier”) is inoculated with a representative test virus and the virus is dried onto the carrier. The inoculated carrier is exposed to an aliquot of the use dilution of the test substance (liquid products), or to the amount of spray released under use conditions (spray products). The carrier is held for the requested exposure time at the requested exposure temperature. Following exposure, the contents of the carrier are neutralized and serial dilutions of the neutralized test substance are performed. The dilutions are then assayed for viral infectivity by an assay method specific for the test virus. Appropriate virus, test substance cytotoxicity, and neutralization controls are run concurrently. Typically, most regulatory agencies require at least a 3 log reduction of the virus in order to claim efficacy.

Disinfection qualification testing

Disinfection Validation/Qualification Against Viruses (USP 1072) - In this method, the disinfection procedures using target viruses are evaluated using representative surfaces and test substances (disinfectants) that would be encountered in a Sponsor’s facility. This testing is described in the United States Pharmacopeia (USP) Chapter 1072. Minimum log reduction requirements are determined by the Sponsor.

Topical skin products testing 

Virucidal Efficacy of Topical Skin Products Utilizing an Ex-Vivo Skin Model - A skin substrate (“carrier”) is inoculated with a representative test virus and the virus is dried onto the carrier. The inoculated carrier is exposed to an aliquot of the use dilution of the test substance (liquid products), or to the amount of spray released under use conditions (spray products) or is wiped per use instructions (pre-saturated towelette). The carrier is held for the requested exposure time at the requested exposure temperature. Following exposure, the contents of the carrier are neutralized and serial dilutions of the neutralized test substance are performed. The dilutions are then assayed for viral infectivity by an assay method specific for the test virus. Appropriate virus, test substance cytotoxicity, and neutralization controls are run concurrently. Percent and log reductions are calculated based on the virus control.

Alternatively, the test substance may be applied to and dried on the skin substrate (“carrier”) in place of the virus. The carrier is then exposed to an aliquot of test virus and held for the requested exposure time at the requested exposure temperature. Following exposure, the contents of the carrier are neutralized and serial dilutions of the neutralized test substance are performed. The dilutions are then assayed for viral infectivity by an assay method specific for the test virus. Appropriate virus, test substance cytotoxicity, and neutralization controls are run concurrently. Percent and log reductions are calculated based on the virus control.

Our team can work with you to develop custom protocols to meet your disinfectant/sanitizer testing needs.

The Element advantage 

Ensure compliance to regulatory requirements for virucidal efficacy claims for disinfectants and sanitizers with Element’s comprehensive disinfectant and sanitizer efficacy testing services. Partner with Element for testing to established methods, as well as for customized protocols tailored to meet your specific needs. Our team stands by the data we develop, and we will work with you and regulatory agencies to answer any questions that may be asked regarding the testing of your product. We are also prepared to defend the testing and the data developed if the need arises.

For more information about Element’s virucidal disinfectant efficacy testing services, contact us today.

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