Regulation Differences: Devices and Chemicals
Regulation Differences between Devices and Chemical Disinfectants
≥ 99.9% kill rate achieved if the following are adhered to: (E-Mist lab research available here)
•Customer selected/provided, water soluble, EPA-registered disinfectant. NOTE: By law, all applicable label instructions on EPA-registered products must be followed and the user assumes liability from any injuries resulting from off-label use.
•Appropriate EPA-registered disinfectant selected
•Integration as protocol: E-Mist Infection Control System AND SanoTech 360™ Certified Process use and training.
Average Droplet Sizes: One micrometer equals 1/25,400 inch (0.001 mm)
•Fogging Device Average Droplet Size: 20 microns
•Misting Device Average Droplet Size: 7-40 microns
•Human Hair: 70 microns
•E-Mist Electrostatic Application Device Average Droplet Size (Dv50): 85.69 microns
NOTE: E-Mist Electrostatic Systems are used to apply user-provided EPA-registered water soluble disinfectants. The E-Mist Electrostatic Systems place a positive ( + ) charge on the droplets as they leave the spray nozzle. The dispersed droplets spread out more evenly and seek out a negative ( – ) or neutrally charged surface. The end result is that your disinfectant is more targeted, provides more uniform coverage with less waste, and like the magnets, attracted to the surface with remarkable force. In fact, chemical droplets will adhere more consistently and more comprehensively to vertical, horizontal and even around most surface areas. Learn More
Regulatory Framework: devices and chemicals
The following is based on the regulatory framework for devices and formulated chemical products that make disinfectant claims for non-critical surfaces in the United States, which may vary from requirements in other countries. Local regulations should always be consulted when evaluating disinfectant claims outside of the U.S.
In the U.S., pesticide products are regulated by the Environmental Protection Agency (EPA) under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), and include antimicrobials like formulated chemical disinfectants that are applied on non-critical surfaces (surfaces that only contact intact skin). Formulated chemical disinfectant substances are approved by the EPA after acceptable data on product performance (effectiveness), toxicological effects, ecological effects, ecological fate and chemistry is submitted for them. EPA-approved disinfectants are granted an EPA Registration Number, which must then appear on the product label. In addition to that, EPA approves a final label with the recommendation of use for these products.
The EPA also regulates devices used to control pests like bacteria – which can include equipment that generates UV light, or water systems that generate ozone – if antimicrobial (sanitizing or disinfecting) claims are being made. However, these devices are not required to be registered at the EPA federal level, as that regulatory approval framework is applied only for formulated chemical substances. Some states do require device registrations, but that process does not involve proof of efficacy.
However, devices are subject to certain labeling requirements, according to FIFRA and those states requiring devices be registered, and one of them is to have an EPA Establishment Number where the device was manufactured. Like formulated chemical disinfectant substances, pesticide devices are required to show that EPA Establishment Number on the label. Users of these devices might misinterpret the EPA Est. No. to mean EPA Registration, and so may be under the impression that they are EPA approved (registered) as sanitizers or disinfectants. More information can be found at http://www.epa.gov/pesticides/factsheets/devices.htm
Pesticide devices that make antimicrobial (bacterial kill) claims, like UV light and water-ozone systems, are not required to be EPA approved because that process is only for formulated chemical disinfectant substances. Therefore, they are not required to present any efficacy proof for the EPA’s review for a final label. The EPA Registration process for chemical disinfectants requires proof of effectiveness be demonstrated to the EPA before approval is granted. Since the EPA does not require proof of effectiveness for devices, manufacturers have the responsibility of evaluating effectiveness. However, manufacturer efficacy data also needs to be reviewed by the end user to determine whether it translates to effectiveness for their specific applications. Devices can have transient and variable effectiveness and the data provided by the device manufacturer should be carefully scrutinized for scientific validity and to determine whether it truly translates to infection risk reduction in the end-users application.
In general, the CDC recommends EPA Registered Disinfectants for non-critical surface disinfection, and only briefly mentions devices in their Guidelines, mainly for applications other than surface disinfection.
CDC Guideline for Disinfection and Sterilization in Healthcare Facilities, 2008 CDC HICPAC Committee EPA DIS/TSS Guidance Documents, Disinfectant Technical Science Section, EPA Office of Pesticide Programs
Environmental Fogging Clarification Statement
CDC and HICPAC have recommendations in both 2003 Guidelines for Environmental Infection Control in Health-Care Facilities and the 2008 Guideline for Disinfection and Sterilization in Healthcare Facilities that state that the CDC does not support disinfectant fogging. Specifically, the 2003 and 2008 Guidelines state:
• 2003: “Do not perform disinfectant fogging for routine purposes in patient-care areas. Category IB”
• 2008: “Do not perform disinfectant fogging in patient-care areas. Category II”
These recommendations refer to the spraying or fogging of chemicals (e.g., formaldehyde, phenol-based agents, or quaternary ammonium compounds) as a way to decontaminate environmental surfaces or disinfect the air in patient rooms. The recommendation against fogging was based on studies in the 1970’s that reported a lack of microbicidal efficacy (e.g., use of quaternary ammonium compounds in mist applications) but also adverse effects on healthcare workers and others in facilities where these methods were utilized. Furthermore, some of these chemicals are not EPA-registered for use in fogging-type applications.
These recommendations do not apply to newer technologies involving fogging for room decontamination (e.g., ozone mists, vaporized hydrogen peroxide) that have become available since the 2003 and 2008 recommendations were made. These newer technologies were assessed by CDC and HICPAC in the 2011 Guideline for the Prevention and Control of Norovirus Gastroenteritis Outbreaks in Healthcare Settings, which makes the recommendation:
“More research is required to clarify the effectiveness and reliability of fogging, UV irradiation, and ozone mists to reduce norovirus environmental contamination. (No recommendation/unresolved issue)”
The 2003 and 2008 recommendations still apply; however, CDC does not yet make a recommendation regarding these newer technologies. This issue will be revisited as additional evidence becomes available.
•Atomization: The process of generating drops is called atomization. The process of atomization begins by forcing liquid through a nozzle. The potential energy of the liquid (measured as liquid pressure for hydraulic nozzles or liquid and air pressure for two-fluid nozzles) along with the geometry of the nozzle causes the liquid to emerge as small ligaments. These ligaments then break up further into very small “pieces”, which are usually called drops, droplets or liquid particles. Each spray provides a range of drop sizes; this range is referred to as a drop size distribution. A simple explanation of this process is the breakup of a liquid as it emerges from an orifice. Various spray nozzles have different shaped orifices and produce various spray patterns such as hollow cone, full cone, flat spray and others. The drop size distribution will be dependent on the nozzle type and will vary significantly from one type to another. Other factors such as the liquid properties, nozzle capacity, spraying pressure and spray angle can affect drop size too. In order to accurately assess and understand drop size data, all of the key variables such as nozzle type, pressure, capacity, liquid properties and spray angle have to be taken into consideration.
•Droplet size: Drop size is a by-product of atomization. Drop diameters are usually expressed in micrometers (microns or µm). One micrometer equals 1/25,400 inch (0.001 mm).
•Volume Median Diameter: Volume Median Diameter (VMD or Dv0.5) in micrometers (microns or µm) for a single nozzle at identical conditions can be determined using either flux or spatial samples.
Factors Affecting Drop Size
Drop size and drop size uniformity will vary based on several factors: characteristics of the solution; the solution viscosity; the spray nozzle design; the flow through the spray nozzle and the air pressure if two fluid nozzles are being used.
•Nozzle type: Typically, full cone nozzles have the largest drop size followed by flat spray and hollow cone nozzles. This trend applies equally to hydraulic and air assisted nozzles, however, air assisted nozzles provide very fine drops that are smaller in size than traditional hydraulic nozzles
•Flow rate: Flow rate has a direct relation to drop size. An increase in flow rate will increase the drop size; similarly a decrease in flow rate will decrease drop size.
•Pressure: Pressure has an inverse relationship effect on drop size. An increase in pressure will reduce the drop size. A reduction in pressure will increase the drop size.
•Spray angle: Spray angle has an inverse relationship effect on drop size. An increase in spray angle will reduce the drop size. A reduction in spray angle will increase the drop size.
•Liquid properties: Viscosity and surface tension increase the amount of energy required to atomize the spray. An increase in any of these properties will typically increase the drop size
•Viscosity: The property of a liquid that presents resistance to flow due to the existence of internal friction within the fluid. An increase in viscosity:
• Decreases flow rate.
• Creates heavy edges.
• Requires a higher minimum pressure to maintain adequate spray angle/coverage.
• Increases capacity.
• Increases drop size.
•Surface tension: The property of a liquid by virtue of which the surface molecules exhibit a strong inward attraction, thus forming an elastic skin which tends to contract to the minimum area. An increase in surface tension:
• Increases the minimum operating pressure.
• Decreases spray angle.
• Increases drop size.
•Specific gravity: A liquid’s density relative to the density of water — typically measured at 60°F (16°C) where its density is 64.4 lb/ft3 (0.9991 g/cm3 ). Higher specific gravity means lower capacity and lower specific gravity allows higher capacity.
Spray Analysis Source: http://teejet.it/media/40081/understanding%20drop%20size.pdf
Notice to Reader
The information, recommendations and other statements contained in this document are based upon tests or experience that E-Mist Innovations, Inc. believes are reliable, but the accuracy or completeness of such information is not guaranteed. Many factors beyond E-Mist’s control and uniquely within the user’s knowledge and control can affect the use and performance of an E-Mist product in a particular application. Given the variety of factors that can affect the use and performance of an E-Mist product, the user is solely responsible for evaluating the E-Mist product and determining whether it is fit for a particular purpose and suitable for user’s method of application.