From a BHMA Environmental testing aspect, the following finishes for exterior use are recommended.
Best - 629/630 - Bright or Satin Stainless; no top-coat
Better - 626/682/625 – Satin or Polished Nickel Chrome on BR/ZN
Good - 643E(316) – Aged Bronze on BR/ZN
Fair - 605, 606, 609, 612, 619, 622 - Powdercoat finishes on BR/ZN (Semi-gloss clear-coats)
NOTE: Metal finishes such as Stainless or Chrome should never be cleaned with soap or other chemicals. Clean Stainless or Chrome with a damp cloth and routinely treat with an appropriate polish and/or corrosion inhibitor.
INFORMATION PROVIDED THROUGH THIS SITE IS PROVIDED TO YOU AS IS WITHOUT ANY EXPRESS REPRESENTATIONS OR WARRANTIES OF ANY KIND, AND WE MAKE NO REPRESENTATION OR WARRANTY THAT THIS SITE(OR ANY INFORMATION PROVIDED IN RESPONSE TO YOUR INQUIRY), WILL BE ACCURATE, COMPLETE, OR ERROR-FREE.
YOU AGREE THAT YOU MUST EVALUATE ALL INFORMATION AND RESPONSES, AND THAT YOU BEAR ALL RISKS ASSOCIATED WITH, THE USE OF THIS SITE, INCLUDING ANY RELIANCE ON THE ACCURACY,COMPLETENESS, OR USEFULNESS OF ANY INFORMATION OR MATERIALS MADE AVAILABLE THROUGH THIS SITE.