Specifically, how are products that use silver, Triclosan and silane additives different from solid copper surfaces?
Q: Specifically, how are products that use silver, Triclosan and silane additives different from solid copper surfaces?
A: These additives, used to coat metal surfaces or as ingredients in molded plastics, do not have EPA public health registration and cannot match the ability of CuVerro® surfaces to kill 99.9% harmful bacteria within 2 hours of exposrure, and continue to kill bacteria after repeated contamination.1
In the place of EPA registration, these additive and coatings technologies are listed under EPA’s Treated Article Exemption, which means that the antimicrobial agent (e.g. silver, Triclosan, silane) can only claim to protect the treated product itself from non-specific bacteria, mold or mildew that cause odor and degradation of the treated article. So while a doorknob with silver coating might protect the doorknob itself from degrading from mold or mildew, it cannot claim to protect people touching the doorknob against disease-causing bacteria.
Under this exemption agreement, the EPA does not permit product manufacturers of articles treated with antimicrobials to make claims that their surfaces kill harmful organisms, nor to protect people against disease-causing bacteria.
Products listed with a treated article exemption typically:
- Can not claim to kill microorganisms, but only inhibit growth.
- Are based on leaching technologies in that the antimicrobial agent needs to migrate out from the polymeric surface, and in conditions of moisture or high humidity to be effective.
- Cannot guarantee lifetime durability. Treated products will lose effectiveness over time, especially when rubbed away or scratched.
- Have not been show to be effecitive in normal indoor environments. Rather than being tested under EPA’s GPL tests protocols, treated articles have used the Japanese Industrial Standard for fabric testing (JIS Z2801). Instead of simulating typical healthcare environments for touch surfaces, JIS Z2801 replicates “sock and underwear” conditions (~98oF and ~95% Relative Humidity). Hopefully hospital patients would never be subjected to those conditions.
- And JIS Z2801 only shows efficacy in inhibiting growth after a 24-hour period. In comparison, CuVerro® alloys are effective in killing 99.9% of bacteria within 2 hours of exposure, and typically show 7- to 10-log reductions in bacteria.
For additional informaiton about products listed under the EPA’s "Treated Article Exemption" please visit: http://www.epa.gov/pesticides/factsheets/treatart.htm