One way to render a sealed container free of most oxygen without a nitrogen purge: Use the self-heating gizmos sold as 'hand warmers', 'toe warmers', or plasters for sore backs or muscles. They are available at many pharmacies and sporting goods stores, especially 'up north' where we deal with cold winters. These packets are safe for contact with the skin, so I assume they are also harmless to shells. These things use a mix that includes powdered iron, which rapidly oxidizes to produce warmth as it uses up the available oxygen around it. Air is around 20% oxygen, 79% nitrogen, so taking the oxygen out of it also results in a 20% reduction in volume, effectively pulling a partial vacuum in a closed container as the packet uses up the oxygen, or a decrease in the volume of soft packaging. Note: for long term storage in a 'soft container', low density polyethylene (like little zip-lock baggies) is slightly porous, and will allow oxygen to diffuse in over time. Mylar is very impervious to gaseous diffusion, and would be better, but I haven't delved into looking for little mylar bags.... As a demo: take one of these heating packs out of its little mylar envelope, and tape it to the bottom of a quart jar. Turn the jar (without a lid) upside down in a shallow pan of water and wait a few hours. You will observe the water level rises inside the jar as the oxygen is consumed. - John ________________________________ From: Conchologists List <[log in to unmask]> on behalf of Allen Aigen <[log in to unmask]> Sent: Monday, May 11, 2020 11:07 AM To: [log in to unmask] <[log in to unmask]> Subject: Re: [CONCH-L] fading colors. Those shell colors that fade quickly after a live animal was collected, even when the shell was kept in the dark, apparently are reacting to oxygen. It is not practical or aesthically satisfying to vacuum pack your shells in plastic bags, or pump nitrogen in first, but it might be worth it if you are planning to send it to someone else. Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10 ---------------------------------------------------------------------- [log in to unmask]<mailto:[log in to unmask]> - a forum for informal discussions on molluscs To leave this list, click on the following web link: http://listserv.uga.edu/cgi-bin/wa?SUBED1=conch-l&A=1 Type your email address and name in the appropriate box and click leave the list. ---------------------------------------------------------------------- ---------------------------------------------------------------------- [log in to unmask] - a forum for informal discussions on molluscs To leave this list, click on the following web link: http://listserv.uga.edu/cgi-bin/wa?SUBED1=conch-l&A=1 Type your email address and name in the appropriate box and click leave the list. ----------------------------------------------------------------------