Lead (Pb)-Free UHV Viewports
Sustainability Without Compromise
It's important to note that RoHS compliance doesn't automatically guarantee Pb-free status. Contrary to common assumptions, not all RoHS-compliant UHV fused silica viewports are Pb-free. While the RoHS Directive restricts solder content to less than 0.1% Pb, an obscure exemption for solders containing over 85% Pb allows manufacturers to label high-lead products as RoHS compliant.
Surprisingly, most "brazed" UHV fused silica viewports are actually soldered with a 97% lead alloy, exceeding RoHS limits by more than 3,000 times for an equivalent volume of eutectic tin-lead solder. This expedient yet environmentally questionable sealing method disregards the long-term impact, potentially leading to discarded viewports in landfills.
"Lead is a persistent environmental contaminant that can cause toxicity even at low blood lead concentrations (BLC).” [1] "Heavy metals in landfill leachate have significant impacts on both groundwater and surface water quality, even at trace levels in leachate". [2] The lessons learned from incidents such as Flint, MI, underscore the need for urgent attention to such hazards.
At Sealed Optics, we take a different approach. We prioritize the production of Pb-free and RoHS-compliant viewport products, including fused silica viewports. Choose sustainability without compromise—explore our UHV sealed CaF2, MgF2, ZnSe, and SiO2 viewports.
