Any luck restoring effectiveness of silica packets?

So, calling all chemists: @GDJMSP warned of possible air contaminants by drying silica packets and canisters in the oven. What say you? I suppose his concern is more with the make-up of the paper and plastic than the silica gel (since silica gel is dried in ovens all the time)?

Steve

 

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I was just speaking as a marine engineer, not a real chemist. I live in the tropics and it is HOT and quite humid much of the year. So far I do not see it damaging my coins. I take no special efforts at limiting exposure to the moisture in the air. I do handle coins carefully and never with wet hands.

 

That "Pink to Blue" thing is due to some cobalt chloride indicator. https://chlorine.americanchemistry....y/Cobalt-Chloride-Colorful-Moisture-Detector/

 

Don't know about you, but I generally put food in a pan, then put it in the oven. I don't just put it directly on the oven floor. At least, not on purpose.

 

I use these https://www.coinsupplyexpress.com/SG-40-Hydrosorbent-Dehumid-sku-2280.html
Already referenced by @GDJMSP

 

By that logic if you ever burned a takeout container or some pizza rolls you should replace the oven.

Those packets were used to keep medications dry. Shipped in the summer sun, those packets easily reached 150 degrees F in contact with pills you take internally.

If you are concerned, run a self cleaning cycle.

 

I tried that, @Burton Strauss III, with a quart of prune juice and a dozen warm molasses cookies. Mission accomplished.

Steve

 

The small packets are not worth saving. There is almost as much packaging as there is silica gel. I use the 450 gram cloth bags of silica gel that come in a box with an indicator. You stick the cloth bag in the oven for 3 hours at 240 degrees. No reason to leave the door of the oven open. The moisture cooks away.

 

In fact, our oven has a small chimney under the right rear burner to let out steam. Baking food produces a lot more steam than baking a pound of used silica gel.